Consider this Before Jumping on the Cloud

Thinking about jumping on the cloud? True, I’ve had no qualms in showing my skepticism towards the marketing of ‘cloud computing’ and it being the mere repackaging of solutions which have existed for years, but the fact is it still addresses a concept and reality that exists and one which holds numerous benefits. Indeed abandoningan existing on site IT infrastructure for a cloud provider that most often or not can’t offer the same level of security, control or performance is not an easy decision but one which CIOs and IT executives are seriously considering when weighing up the economic benefits. As with any change though, a move towards the cloud necessitates a sound and comprehensive assessment to avoid the trap of a short term benefit turning into a long term nightmare.

Integration Considerations:

Firstly your company should assess its business strategy and whether a cloud computing infrastructure could integrate with it. With all the convenience that cloud offers, the risk of data residing beyond your company’s vicinity still presents a significant security risk. Hence depending on your company, whether that be a startup, small, medium or enterprise an assessment of how much risk you are prepared to take in order to cut costs will initially be the first factor in deciding which data / applications to outsource to the cloud. This is what often leads enterprises to be content with using the cloud for archival while smaller business find it easier to go the whole nine yards. Once that’s decided your design for integration should first evaluate each process and system and determine the number of simultaneous requests that need to be handled. As always availability of information also needs to be paramount, regardless of whether the information resides internally or on the cloud. Thus the key for enterprises is to not think of the cloud as a substitute for their processes, policies and security but rather an extension of their existent architecture.

Choosing the Right Cloud:

If your company needs access to e-mail, e-commerce, gaming applications, etc. with cost reduction being the primary concern over security and availability then the public cloud provides the service to access such applications via a thin device with minimal financial overhead. Here the start up business can thrive but companies with an already substantial customer base and Tier 1 applications such as OLTP should think otherwise. In such an instance a hybrid cloud may be most suitable wherein the Tier1 application data remains in house with the cloud being utilized for backup, archiving and testing bringing in the consequent cost savings. Enterprises on the other hand with strict Sarbanes Oxley and security controls on customer data and service levels may outweigh the risk of information access control over cost and leave the cloud altogether, that is until security in the cloud becomes further enhanced.

Testing the Cloud with your Existent Virtualised Infrastructure:

The balance of scales will always alternate between the reliable and secure nature of data centers with the far cheaper ‘pay as you use’ option of cloud computing. Therefore a way to get a taste of the cloud and assess its suitability to your environment is to utilize the virtualization that is already taking place within your data center. If you are one of the few archaic infrastructures that has not already moved towards the virtualization of applications and infrastructure then you are already missing out on immediate cost benefits which could be existent within your own data center or what the marketing teams tag ‘the internal’ or ‘private’ cloud. With the independence of applications from their physical infrastructure, your in house virtualisation already provides the gateway and flexibility to cloud offerings which are based on external virtual infrastructures. By choosing a non-core application to experiment with such as your e-mail archiving you can quickly set up a test environment and get a feel of the bottlenecks, security, performance and billing procedures of the cloud. Upon sufficient testing and having gained an idea of the metrics you required, you will have a better idea and peace of mind on how best to deploy more mature applications to the cloud.

Choosing the Right Applications:

Choosing the right applications is also a serious precursor as not all applications are best suited for the cloud. If PaaS and IaaS are a consideration then a migration may be a necessity if the cloud may not support your application especially if there are incompatibility issues between the platform software and your application. Another issue is related to applications that require real time response that can’t be put at the risk of potential network latency, congestion or bandwidth clogging. Tight backup windows, graphics intensive applications or applications handling large I/O would need serious consideration and investigation of the SLAs provided by the cloud prior to any migration. On the flip side applications linked to your non core business operations may be ideal for deployment such as a marketing campaign website or a standalone application that doesn't require much interaction with other applications. Again applications which are used for testing purposes can easily be deployed to the cloud with minimal costs and risks to the business especially with many cloud providers offering free trial periods.

To conclude while network latency, data availability, security and application support are all valid concerns for customers thinking of utilizing the cloud, a sound approach and pre-analysis could easily alleviate them, bringing in major cost savings to your business. In other words jumping on the cloud bandwagon without the right assessment might see you falling straight through from the sky; but making sure the cloud you do jump on is substantial enough to support and sustain your company could also be the soundest business investment you’ll ever make.

Some think it's as easy as building bricks:

Are SUN to end Hitachi Data Systems OEM Relationship?

On January 26th just prior to the official announcement of Oracle’s takeover of SUN Microsystems, I confidently predicted in my article “SUN’s Oracle Merger” with regards to SUN’s storage portfolio that “One certainty is that the OEM partnership with HDS’ enterprise arrays will continue.” Perhaps it’s time to eat some humble pie. If current indications are anything to go by, it’s more than likely that the SUN agreement of reselling HDS Enterprise Storage may be coming to an abrupt end.

Oracle clearly have a different business approach to their customers than SUN Microsystems did, and that includes dealing with Hitachi Data Systems. Admittedly I‘ve never been a great fan of SUN’s storage systems, often finding them to be the epitome of a server company that builds storage i.e. a box with lots of disks and sparse in-built intelligence. But with the recent launch of the 7000 series (which still may come under scrutiny by NetApp considering it’s more than coincidental similarities) and the intelligent storage systems built by Larry Ellison’s other plaything Pillar Data Systems, their modular market is now pretty well covered. How Oracle/SUN could plan to cover the gap that will be left from a potential removal of the USPV / USPVM (ST9990V /ST9985V) could lie with the approach shown with the recent Exadata V2. Oracle databases that are directly attached to boxes chocked full of flash drives may well be the answer Oracle/ SUN will be offering to get themselves free from the entanglement of Enterprise storage vendors.

While there seems to be a game plan of some sort in the Oracle/SUN camp, if this supposition were to come true it will have major implications on Hitachi Data Systems and their next steps forward. Personally I’m happy if this will happen as it may at last be the kick up the ‘Back End Director’ that HDS need to finally start marketing and addressing a customer base, certainly within the EMEA region that is still oblivious to its existence. I’ve often shown my frustration at HDS and their inability and lack of drive to push forward their brand and products to consumers who have settled for inferior products from other vendors that were merely marketed better. Resting on the laurels that HP and SUN were rebadging and reselling their Enterprise Systems and doing all the hard work for them, the downside was that HDS’ cross bar architecture storage systems and virtualization technology were firmly placed in thousands of datacenters, unbeknownst to the IT Directors that bought them. Another issue was that unlike the SUN relationship in which only the colour of the doors and the SUN badge changed, HP buy HDS Enterprise Storage Systems and actually change the microcode making them more ‘HP’ than ‘HDS’. So a true untainted HDS USPV could now potentially only be purchased from Hitachi Data Systems themselves. This could be the beginning of a HDS revolution or a slow withering death of sales.

But I’m confident if the leadership at HDS takes the right steps and investment, this could finally be the key to a future market share they have been lacking in. There is no doubting the quality of the HDS Enterprise range from the still reliant cross bar architecture and vIrtualisation through the array USPV systems. Hence maintaining those sales and support deals with existent SUN customers may not be such a great overhaul especially with an updated USPV on the horizon. Where the real challenge lies is drawing customers to the equally good modular AMS and WMS range which are rarely found in Datacenters yet alone virtualized behind their own Enterprise Storage Systems. Also the HNAS range made by BlueArc are also a range to be reckoned with but are hardly making NetApp sales guys break a sweat as potential customers are often unaware of their existence. Plus all the latest initiatives which HDS have taken such as High Availability Manager, IT Operations Analyzer, or the Hitachi Content Archive platform HCP, as excellent as they are, are still not making the waves and marketing noise their credentials deserve.

So in a twist of fate, should the continuation of the SUN OEM relationship fall through, Hitachi Data Systems may be forced into being the marketing machine it up to now has shied away from in order to maintain and advance its presence in the industry. The positive thing is that the products are and always have been good enough – now it’s time for the marketing guys to promote it.

The Best Back Up Solution for VSphere4?

When VMware first introduced VCB as part of the ESX package, it never did seem more than a temporary / complimentary solution for customers who had a small environment of 100 VMs or less. With the launch of VSphere4 and the subsequent introduction of APIs which allowed external applications and scripts to communicate directly to the ESX, it was apparent that VMware was beginning the gradual move to offload the backup solution to the Backup experts. Now having run with VSphere4 for more than six months, it seems a good time to assess and evaluate who has taken advantage and the lead with incorporating all the latest features of ESX4.

To recap; with VMs being encapsulated in a single disk file the principal was that image-level backups instead of traditional file-level allowed backups to be much faster. With VSphere4, VMware introduced improved support for thin provisioning which not only had the potential to reduce the amount of actual storage allocated but also shorten backup windows. The idea was straightforward; by using thin provisioning the system admin is given the ability to over-commit disk space, especially handy as the majority of VMs don’t use all of their allocated disk space. Thus this eradicates the problem with the majority of disk-to-disk backup applications using image-level backups i.e. no more backing up of a complete virtual disk file of a VM when most of it wasn’t actually used.

Another new addition to VSphere4 and it’s vStorage APIs was the feature of CBT (Changed Block Tracking). With CBT the VMkernel could now track the changed blocks of a VM’s virtual disk. Just by querying the information using an API call to the VMkernel, CBT alleviates the burden from the backup applications having to scan or keep track of changed blocks. This results in much quicker incremental backups as the overhead of scanning the whole VM image for changes since the last backup could now be eradicated.

So in looking around for solutions which best incorporated these new features I eventually came across Veeam. Utilising the thin provisioning feature to remove the overhead of no longer seeking out empty disk blocks and the unnecessary backing up of those empty blocks, Veeam also incorporates compression algorithms on the target backup device. Hence Veeam have a solution that not only reduces the amount of space used on the source host datastores but also the target backup storage device.

Furthermore Veeam are currently the only third party API that offer support for CBT, although ESXpress are promising something similar with their upcoming version 4. Veeam have come up with several different modes to utilise the CBT feature namely, SAN mode, Virtual Appliance mode and Network mode. Each mode brings less I/O to each device depending on your setup and thus less resource consumption when performing backups consequently leading to reduced backup windows.

So while Veeam are currently leading the way, the time is certainly ripe for more third party APIs to be developed and incorporated making VM backup nightmares a thing of the past.

Infiniband – Boldly Going Where No Architecture Has Gone Before

Back in 2005 we all knew that Fibre Channel and Ethernet would eventually support transmission rates of 10 Gbit/s and above and now in 2010 that day has pretty much dawned on us. In the excitement of those days what was always a concern was that the host’s I/O bus would need to transmit data at the same rate. But with all the advancements of PCI-E, the nature of all parallel buses is that their transmission rate can only be increased to a limited degree so how was this potential barrier ever going to be solved? The solution being penned around at the time was InfiniBand. Not only did it carry a name that seemed straight out of a Star-Trek episode but it also promised a ‘futuristic’ I/O technology which replaced the PCI bus with a serial network. That was five years ago and bar a few financial services companies that run trading systems I hadn’t really seen any significant implementations or developments of the technology that was marketed with the phrase ‘to Infiniband and beyond’. But two weeks ago that suddenly changed.

Before I delve into the latest development of the architecture that’s bold enough to imply ‘infinity’ within its name one should ascertain as to what exactly justifies the ‘infinite’ nature of Infiniband. As with most architectures the devices in Infiniband communicate by means of messages. That communication is transmitted in full duplex via an InfiniBand switch which forwards the data packets to the receiver. Also like Fibre Channel, InfiniBand uses 8b/10b encoding enabling it to package together four or twelve links to produce a high transmission rate in both directions. Using Host Channel Adapters (HCAs) and Target Channel Adapters (TCAs) as the end points, the HCAs act as the bridge between the InfiniBand network and the system bus while the TCAs make the connection between InfiniBand networks and the peripheral devices that are connected via SCSI, Fibre Channel or Ethernet. In other words for SAN and NAS folk that basically means HCAs are the equivalent to PCI bridge chips while the TCAs are in the same vein as HBAs or NICs.













Additionally HCAs carry the ability to be used for not just interprocessor networks, attaching I/O subsystems, but also for multi-protocol switches such as Gbit Ethernet switches. Herein lies the promise of a sound future with Infiniband due to its independence from any particular technology. Indeed the standard is not just limited to the interprocessor network segment, with error handling, routing, prioritizing and the ability to break up messages into packets and reassemble them. Even messages can be a read or write operation, a channel send or receive message, a multicast transmission or even a reversable transaction-based operation. With RMDA existent between the HCA and TCA, rapid transfer rates are also easily produced as the HCA and TCA each allow permission to read or write to the memory of the other. Once that permission is granted write or read location is instantly provided thus enabling the superior performance boost. With such processes, control of information and it’s route occurring at the buslevel, it’s not surprising that the InfiniBand Trade Association view the bus itself as a switch. Add to the equation that InfiniBand uses Internet Protocol Version 6, you’re faced with an almost ‘infinite’ amount of device expansion as well as potential throughput.

So fast forwarding to the end of January 2010 and I finally read headlines such as ‘Voltaire’s Grid Director 4036E delivering 2.72 terabits per second’. At last the promise of Infiniband is beginning to be fulfilled as a product featuring 34 40 Gb/s InfiniBand ports i.e. a collective 2.72 terabits per second proved this was no longer Star Trek talk. With an integrated Ethernet gateway which bridges traffic between Ethernet-based networks via an InfiniBand switch, the Voltaire 4036E is one of many new developments we will soon witness utilsing Infinband to provide unsurpassed performance. With high performance requirements for ERP applications, virtualization and ever growing data warehouses always increasing, converging Fibre Channel and Ethernet with InfiniBand networks into a unified fabric now seems the obvious step forward in terms of scalability. Couple that with the cost savings on switches, Network interface cards, power /cooling, cables and cabinet space and you have a converged network which incorporates an already existent Ethernet infrastructure.











InfiniBand suppliers such as Mellanox and Voltaire may have their work cut for them with regards to marketing their technology in the midst of an emerging 10gigE evolution but by embracing it they may just ensure that Infinband does indeed last the distance of ‘infinity and beyond’.

Sun’s Oracle Merger – A marriage made in heaven or a deal with the devil?

With only the ‘you may now kiss the bride’ custom to follow, the ORACLE/SUN marriage (or dare I say SUN/ORACLE) is now finally complete. After months of legal wrangling which has caused nothing but embarrassment and dwindled SUN’s stature within the market sphere, reports also came out that half of Sun's 27,000 staff will be made redundant. Thus initial indications are clear that Oracle, known for its past agnosticism to open source has an eye for the merger being based on maximizing profit. In the meantime Sun’s competitors are probably smiling wryly as the delay of the merger played into their immediate interests but what threats and challenges does this partnership now pose to the once great open source vendor which did so much for developing the tech and e-commerce industry.

One thing which Oracle will most probably do is address and remediate the main cause for Sun’s tragic decline prior to the days when talk of ‘takeovers’ and ‘falling stock shares’ became the norm. In my humble opinion that was linked to Sun failing to consolidate on its strengths by audaciously venturing into unknown avenues only to find that it couldn’t compete with the existent competition. By spreading itself too thinly the ambitious nature of the company soon led it into labyrinths it couldn’t escape from. One such adventure was its acquisition of StorageTek.

StorageTek, known for their solid modular storage arrays and robust tape libraries had a decent reputation of their own prior to Sun’s takeover. Data Center managers, IT Directors and their like knew they had solid products when they purchased the brand StorageTek but in a miscalculated maneuver, Sun decided to rename all their Storage products with the Sun Microsystems brand. Suddenly Sun’s Sales team had to sell what for the average IT Director was seemingly a new and unproven product based on an unneeded name change. Additionally when these storage products took on the same name as Sun’s other storage company, StorEdge further confusion came into the mix. Couple that with an emerging market for disk based backups, purchasing a company that’s forte was tape libraries didn’t particularly make the best business sense.

So what future does Oracle have in plan for Sun’s current Storage portfolio? One certainty is that the OEM partnership with HDS’ enterprise arrays will continue, but as for their own range of modular arrays the future doesn’t look so promising. In a market with products such as EMC’s Clariion, HDS’ AMS range and ironically Larry Ellison’s Pillar Data systems, the truth of the matter is that Sun’s current modular range simply can’t compete. As cost effective as they are, their performance and scalability were always limited in relation to their direct competitors, something that was already acknowledged by Sun prior to the takeover when they disbanded the SE6920 due to its direct competition with the HDS equivalent USPVM.

Furthermore if Oracle’s push with the Exadata V2 is a sign of things to come, one can hardly see them developing an integrated backup model based on an increasingly frowned upon tape infrastructure made by StorageTek. Don’t get me wrong, I’ve worked with the SL8500 tape library and often wonder in amazement as the robotic arms gesticulate as if they were in the climactic scene from a Terminator movie. But that’s the problem …. it’s so 1990s. Add to the equation the NAS based SUN 7000 Unified Storage System which has received rave reviews and the question resonates as to whether Oracle will forsake its modular storage and tape libraries to further focus on just this trend.

Another venture in which Sun entered yet in hindsight did little to further their reputation was server virtualization. While VMware was taking off at the time with ESX 3 and the magic of Vmotion, DRS, HA, VCB etc. Sun had the dilemma that the server virtualization revolution taking place was compatible on x86 architecture and not Sun’s mainstay SPAARC. Not satisfied with reselling VMware for its x86 platforms, Sun decided to introduce their own version of virtualization which was compatible with their SPAARCs, namely Global zones. With huge monster servers such as the M series, the concept was to have numerous servers (zones) utilizing the resources of the one physical box i.e. the global zone. But in an industry that was moving further towards blade servers and consolidation via virtualization, the concept of having huge physical servers housing several virtual servers that couldn’t be Vmotioned and could only offer high availability by having a cluster of even more huge servers, seemed bizarre to say the least. No one disputes the great performance and power of Sun’s SPAARC servers but to offer them as a virtualization platform is completely unnecessary. Moreover the x86 platforms which haven’t radically changed over the years apart from their purple casing now being a slicker silver one, have also proved to be less than reliable when ESX is installed upon them. Indeed my only experience of the legendary PSOD was on the one occasion I had witnessed ESX installed on Sun x86 hardware. As RedHat and others make moves into the virtualization sphere with solutions superior to the Sun model, the questions begs as to what role virtualization will hold for Oracle. Larry Ellison has already made it evident that he wants to give full support for the SPAARC, but I’m not so sure, especially when Oracle decided to house Intel Xeons and not Sun SPARCs as the core of their Exadata V2.

As for the excellent host based virtualization of VirtualBox, the opensource nature of the product simply doesn’t fit in with Oracle’s approach of utilizing its dominant position to leverage big bucks from its customer base. With Oracle also already having Xen-based virtualization technology, I doubt virtualization will remain in the development radar of the newly occupied Sun offices. Come to think of it, will any of the opensource products remain?

Another aspect which worries me even further is the future of Solaris and ZFS. Despite Larry Ellison’s quotes of focusing on Java and Solaris, Solaris administrators still feel a touch uneasy, something which RedHat have taken advantage of by offering discount Solaris to RedHat conversion courses. As for ZFS, I’ve made no qualms as to my admiration of what is the most system admin friendly file system and logical volume manager on the market. But the recent legal wrangling over copyright with NetApp which is sure to escalate and Apple’s subsequent rejection for their OS leaves the revolutionary filesystem in a rather precarious position. Is Oracle going to put up a fight or will it be a case of no profit means no gain?

Despite the great wedding celebrations and fanfare which will inevitably occur during the honeymoon period, I will sadly shed a tear as a fair maiden that believed and stood for the virtues of platform independent technologies is to be whisked off into the sunset by another burly corporate man. One can only hope that the aforementioned kiss is one of love and understanding which will rejuvenate Sun and not a fatal kiss of death.

Green Storage: MAID To Do More Than Just Spin Down

The fundamental Green problem of all data centers is that they cost a fortune to power up, which in turn produces heat which then costs a fortune to cool down. Within this vicious circle a bastion was set up to counter this, namely ‘Green Storage’, which has mostly taken shape in the form of virtualized storage, data deduplication, compression, thin provisioning, DC power and SSDs. Add to the circle power conservation techniques such as server virtualization and archiving onto nearline storage, and you have most companies claiming they are successfully moving towards being ‘Green’. Hence bring forth the proposition of MAID storage and many users would not see the need for it. Further reluctance towards the technology would also come from the fact that MAID has now somewhat tragically become synonymous with being merely a disk spin down technique, despite having the potential to be far more and concurrently bringing greater cost savings.

First coined around 2002, MAID (a massive array of idle disks) held a promise to only utilize 25% or less of its hard drives at any one time. As Green technology became fashionable, major storage vendors such as EMC, HDS, Fujitsu and NEC began incorporating MAID technology promising that drives could power down when they weren't in use, thus extending the lifecycle of cheap SATA drives and in turn reducing the costs of running the data center. But caught in the midst of being one of many features that the larger vendors were trumpeting, the development and progress of MAID failed to advance from its disk slowdown tag, leaving Data Center and Storage managers oblivious of its full potential. Furthermore MAID became associated with being a solution only suited for backups and archive applications as users were cautious of the longer access time that resulted as disks spun up after being idle.

Fast forward to 2010, with government regulations demanding more power savings, and the back of a year which saw data grow while budgets shrank, suddenly users are looking for further ways to maximize the efficiency of their data storage systems. Hence in a world where persistent data increases a hero in the vein of MAID may just be ideal.

To be frank, the detractors did have a point with the original MAID 1.0 concept which in essence was simply to stop spinning non-accessed disk drives. Also with a MAID LUN having to use an entire RAID group, the prospect of a user with less than a large amount of data meant an awful lot of wasted storage. Add in the scenario of data put on MAID that suddenly requires more user access and hence constant disk spin and the overall cost savings became miniscule. Therefore those that did go for MAID ended up utilizing the technology for situations where access requirements and data retrieval were not paramount, i.e. backup and archiving.

In retrospect what often gets overlooked is that even with tier 2 and tier 3 storage data only a fraction is frequently accessed therefore leaving MAID as a suitable counterpart to the less-active data sets. In conclusion the real crux of the matter is the potential access time overhead that occurs as disks have to be started up, which is a given when only one spin down level is available.

Now with updated ‘MAID 2.0’ technologies such as AutoMAID from Nexsan, varying levels of disk-drive ‘spin down’ are available which utilize LUN access history to adjust the MAID levels accordingly. With Level 0 you have hard drive full-spin mode, with full power consumption and the shortest data access time while Level 1 allows the unloading of disk read/write heads giving 15%-20% less than Level 0 in power usage and only a fraction of a second less in access time. Additionally you have Level 2, which not only unloads the disk heads but also slows the platters a further 30-50% from full speed, giving a 15 second range for access time on the initial I/O before being jolting up to full speed. Similar to MAID 1.0, Level 3 allows the disk platters to stop spinning; bringing power consumption down by 60%-70% with an access time of 30-45 seconds on the initial I/O. In a nutshell these various levels of MAID now open up the doors for the technology to be a viable option for both tier 2, 3 and 4 storage data without the apprehension of delayed access times.

Some companies have gone even further with the technology by adding the ability to dedupe and replicate data in its libraries. Thus users have the option to isolate drives from the MAID pool and dedicate others for cache, leaving the cache drives to continuously spin while simultaneously increasing the payback of deduplication. The possibilities for remote replication as well as policy-based tiering and migrations are obvious. An organization with a sound knowledge of their applications could make significant savings moving data off expensive tier 1 disks to a MAID technology that incorporates both deduplication and replication capabilities with minimum if any performance loss.

Moreover using MAID technology in a context where data becomes inactive during the night (user directories, CRM databases etc.), disks can easily be spun down when users leave their office. Saving on unnecessary spin cost and energy for numerous hours each evening, by also using an automated process for long periods of inactivity such as holiday periods, users would quickly increase energy savings as well as decrease man management costs.

No doubt that in the current mainstream MAID is still best suited for persistent data that's not static and depends largely upon accurate data classification practices. But once MAID 2 and its features of variable drive spin-down, deduplication and replication begin to get the attention they deserve, we may well see a ‘Green’ solution which really does bring significant cost savings and energy savings. With the real ‘Green’ concern of most IT Directors being that of the paper kind with Benjamin Franklin’s face on, that attention may just occur sooner than we think.

When RAID 10 Is Worth The Economic Cost

Faced with the prospect of the extra disks needed for RAID 10 or the heavily marketed RAID 5, most users would go with the economic option and choose the latter believing they avoided themselves potential capacity problems for the future. But with 15k FC disks now seen as a norm for an OLTP (with some users even going for SSDs), the need to decide between RAID 10 or RAID 5 is something that needs to go beyond economic considerations.

The benefits of Storage administration becoming easier and more accessible via GUIs and single management panes has ironically led to the downside of an emergence of poor storage practices becoming more common place. Enterprise storage systems with unbalanced loads on their BEDs and FEDs, write pending cache levels which are too high despite an abundance of cache, array groups hitting maximums while others are dormant are just some of the situations occurring and causing unnecessary strains and performance problems. Coupled with the sometimes negligent approach to equating the application demands with the relevant storage, performance degradation of expensive high end arrays often leads to hard to trace degraded replication and back up procedures.

Hence the obvious case for RAID 10 to be considered instead of RAID 5 for an OLTP or Exchange database falls in a similar category, with an onset of Storage administrators ready to shake their heads in disagreement, content with the current performance they’ve attained with RAID 5. While on the surface that may be the case, a closer inspection as to how the arrays are affected with regards to the variations in read/write combinations coming from different hosts quickly paints an alternate picture.

In the case when several hundred reads and writes bombard the system, suddenly the effects on the array become apparent. Even with the best tuned cache you will struggle in such a situation if the amount of data reaching the FEDs can't be passed on at the same rate to the BEDs. The result is a high write pending cache level which will then lead to other problems such as high I/O wait times on the host or even arrays unable to accept further writes due to a chockablock backlog. The point to remember is that just because the host believes it has completed its writes, the actual writes being committed to disk are still the responsibility of the array. Like any Christmas shopping rush, order is maintained by a steady flow of customers going through the shop doors avoiding crushes, stampedes and eventual door blocks. In the same vein, pending writes in cache need to be written to disk at a rate similar to how they come in.

With the parity-based RAID 5, applications with heavy random writes can easily cause high write-pending ratios. Thus the suitability of RAID 10 for such applications becomes evident. For sequential reads and writes RAID 5 works a treat due to the minimized head movement. Yet if you fall for the trap of placing a write-intensive workload on RAID 5 volumes instead of RAID 10, you will soon have the burden of the overhead of parity calculations which will in turn affect the performance of the processors. Therefore the erroneous conclusion that saving costs by utilizing RAID 5 and compensating the performance with more cache will only lead to a high write pending level. Hence establishing the ratio of reads and writes generated at the host level and concurrently matching the appropriate RAID type will lead to better performance as well as optimization of your storage array.

To conclude a high write-pending utilization on your cache, could be the symptom of an imbalance on either your host or storage system. If your host has volume management that has striping deployed on the volumes, chances are you're probably not spreading the stripe across all the BEDs. Furthermore the RAID type is probably not the most suitable. With migration tools / software such as Hitachi’s Tiered Storage Manager (formerly known as Cruise Control) it’s a straightforward process of migrating data from one LUN to another transparently, thus allowing you to change from a RAID 5 to a RAID 10 parity group. In such circumstances the cost of RAID 10 may be higher but the performance costs related to mismatching the RAID to the relevant applications will be more so.

Internal Clouds – Marketing the Non-Existent

I was recently asked my opinion on what were the main considerations for Cloud Computing with specific emphasis on Internal Clouds. Eager to assist I quickly gave a rundown of issues which included SLAs, distinguishing charge rates, security etc, etc. Pleased with the response received our conversation then veered off into another direction but then it struck me – I had just fallen victim to the marketing jargon. Internal Cloud? What on earth was he asking me and what on earth had I just answered with?

I thought back and reassessed my understanding of the Cloud to what I originally understood it as i.e. that the Cloud was beyond the realms of the datacenter and certainly not internal. Facts told me that Cloud storage services whether it be a backup or archive reside outside of the local datacenter and into the ‘clouds’ even to the extent of being in another continent.

So how then does the oxymoron of ‘internal cloud’ exist so much so that in depth conversations are taking place between consultants, IT managers and Storage Engineers at a datacenter near you? The answer is simple; marketing. Not content with pushing Cloud and SAAS as the future low end tiered storage, the term ‘internal clouds’ is now being marketed and ascribed to new and upcoming products which in essence are only offering added support for virtualization or clustering.

The metaphor of an ‘internal cloud’ i.e. a cloud which now exists within the datacenter leads to a rather ironic image of a misty atmosphere that causes even more confusion. Blow those ‘internal clouds’ away from your datacenter and what you’ll see are flexible solutions for scalability whether they are in the guise of global namespaces, clustering, grid storage or virtualization; solutions which were already known about and quite possibly already existed within your datacenter but were now coined as ‘internal clouds’. Hence once the haziness has disappeared it’s clear to see that the internal cloud that we’ve been marketed with never really existed in the first place.

So should I be asked my opinion on internal clouds again, let’s just say that this time my answer will require no words but a straightforward raise of the eyebrow and a protruding of the chin.

'NetApp & Microsoft' vs 'EMC Cisco VMware'

2009 seems to have been the year of corporate marriages but whether they are marriages made in heaven is yet to be seen. The ongoing saga between Oracle and Sun and their child ZFS is already suffering from the clutches of the scorned mistress ECC, while the Dell/ Perot and HP/3Com matches are still in their honeymoon period. One partnership though which does look likely to stand the test of time and causes the biggest threat to all others is that of Cisco, EMC and their wonderkid Vmware.

The discussion on how in my opinion these three will monopolise the future of ILM and cloud computing is a blog in itself but my thoughts are best expressed and summarised in a response to a recent conversation I had with a Snr Technical Consultant from an unnamed storage vendor. Scoffing at EMC and what he felt was an erratic spending spree of buying out competitor alongside overhyped marketing jargon which lacked any real focus or gameplan, I begged to differ and pointed out my conclusions:

Point 1: Already established with the DMX, when EMC purchased the Clariion, they acquired arguably the best modular storage array on the market such that still today companies such as Pillar and Huawei Symantec find it hard for their own excellent products to compete with. EMC then purchased Vmware, a server virtualisation platform which is now at the forefront of the technology and continues to innovate and lead the way for other companies to try and follow suit – the recent RedHat Virtualisation platform a prime example.

Point 2: More recently the target based deduplication masters DataDomain have been added to the portfolio to accompany their acquisition of Legato Networker and their source based deduplication tool Avamar. Hence Storage, Server virtualisation and Backup and Recovery are bases well and truly covered.

Point 3: As EMC pushed forward the V-Max alongside flash SSDs, the next approach was towards cloud computing and with cloud computing's major concern being security does it come as no surprise that EMC have also purchased the security firm RSA?

Point 4: By bringing Cisco on board, they have a partner whose clout is already proven in the DataCenter such that based on their IP customer base they were able to muscle themselves in on what was quintessentially Brocade's SAN market. With that in mind does anyone really doubt that the UCS platform won't be purchased on a large scale as DataCenter managers look for the best deal to buy in new IP and SAN switches in these economically testing times?

Hence my final point to the vendor consultant - Erratic these decisions have not been but rather well calculated and planned steps towards DataCenter domination.

What I didn't mention to him is that the EMC marketing machine should not be slurred upon with stains of envy but rather commended. The news that FAST is now available for EMC storage systems has the media jumping in a frenzy despite similar products already being available for some time from other vendors. Back in 2008 I had excitedly completed my training on a great new HDS product called Tiered Storage Manager – but rarely did I see the press mentioning its great value to ILM in the same manner.

So what now of the news that Microsoft and NetApp have refused to join the lonely hearts club and concert their efforts to form a new strategic collaboration to enhance the integration of their virtualised server environments? A three year deal, which will probably extend has been pitched as a natural progression which has no relation to the EMC, Vmware, Cisco partnership , (I stroke my chin dubiously) and one that will focus on better offerings in virtualisation, cloud computing, data management and storage. After losing out on Data Domain to EMC, a partnership with Microsoft is good news for NetApp and a step in the right direction as virtualised infrastructure solutions based on Windows Server 2008 R2, Microsoft Hyper-V Server 2008 R2, Microsoft System Center will seamlessly integrate with NetApp's own systems.

This leads us to Hitachi Data Systems, who often seem to me to be the solitary playboy who refuses to chase but banks on the quality of his product such that he expects 'all' to come to him. No doubt, HDS products are still top of their game in terms of reliability and arguably performance but their current position to have not partnered with anyone runs in the same vein as their lack of drive for marketing. For a company that offer a full range from SMB to enterprise solutions I have often found it very frustrating that their lack of marketing has often led to customers purchasing inferior products or technical solutions from either competing vendors or OEMs – point in case - see how few HDS enterprise arrays are actually virtualised with their own HDS modular arrays behind them.

As for Europe and the Middle East if you have a DataCenter with HDS enterprise storage, chances are they probably have a Hewlett Packard or SUN Microsystems badge leaving most IT Directors and CEOs unaware that they have HDS products. Couple that with the inevitable scenario of the world being 'V-Maxed' there still isn't any news on the long awaited replacement for the USPV. Moreover after recently visiting the Storage Expo in Netherlands, it was almost surreal to see the HDS stand merely offering free sushi and sumo wrestling dolls, while opposite them EMC were giving demonstrations on their DataCenter tool Ionix.

As storage and virtualization begin to nurture more partnerships than a dating agency and resources become aligned to gain more market share, HDS still remain taciturn. HDS already have top quality NAS products which most people still don't know about, top of the range archiving platforms and modular arrays so what are they waiting for? Perhaps there's a great plan on the horizon and they are being strategically patient....I hope so.