Enterprise Storage

• HDS’ HAM-Fisted Announcement did not impress, with many wondering (So Long And Thanks For All The Fish) what exactly the company had announced. But by week’s end (USP-V and Hitachi High Availability Manager) we had figured out How It Works and even had some time for jokes.
• What should be in the cloud? How about some profiling questions nobody’s asking re: cloud applications
• Want your own iSCSI array? StarWind has responded to your comments, 2TB at no cost!
• What Is a Backup? Some great discussion (Backup to the Future) and a solution: When Is A Copy A Backup?
• Howard Marks is also doing a great job with backup and archiving: See Of Backups and Archives, Storing Archival Data – Part Deux, and All Archive Data is Not Alike
• I joined Chris Evans, Marc Farley, and Greg Knierieman for Infosmack Episode #6 – HDS USP-V announcement, EMC non-competes and changes at VMworld
• ‘Nuff said: And people wonder why I hate HP, Google Could Learn a Thing or Two from EMC, Virtualization: Why Microsoft cares

Misc

• Tim O’Reilly took a look at a technology I just didn’t get, but changed my mind with Google Wave: What Might Email Look Like If It Were Invented Today?
• Want a crazy car to get your mind off of GM and Chrysler? How about the 500-hp Ariel Atom 500 V8
• A wonderfully long and detailed article: Lessons from the Vaccine–Autism Wars
• Finally, take a look at this amazing video: Louis CK “Everything’s amazing, nobody’s happy”

© sfoskett for Stephen Foskett, Pack Rat, 2009. | Back From The Pile: May 30, 2009
This post was categorized as Enterprise storage, Personal, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

This is how we used to avoid hotspots in 1998: Carefully planning every detail of the storage layout.

Each disk drive consists of a spindle of spinning platters with read/write heads move back and forth. Each time you access a piece of data that’s not in cache, the drive moves its arm over the platter to access the correct piece of data. Since each drive can only access one piece of data at once, and since caches can only hold so much data, tuning a system to minimize the number of requests per drive is essential.

Manual storage array layout was an art, but we never fooled ourselves into thinking our designs were optimal. There were just too many intractable problems, so we had to compromise at every turn:

• We usually had no performance data to base our layout decisions on, so we had to rely on guesses and rules of thumb
• Workloads tend to change over time and manual layouts are painful to modify
• The smallest unit of allocation was an entire LUN or drive, so even the best disk layout mixed hot and rarely-accessed data everywhere
• Much of the allocated space was unused, so we used expensive disks to store nothing

One might think that, 10 years later, advances in technology would have solved these basic issues. But for many people using many of the so-called modern mainstream enterprise storage systems, these problems remain.

Like all good systems administrators, I’m a natural control freak. I am uncomfortable letting the system manage itself, having been burned too many times by computers (well, software really) making stupid decisions. It’s analogous to the backlash against anti-lock brakes, traction control, and automated transmissions among racing enthusiasts.

Do we allow technology to help us get better performance, or do we try to micro-manage everything? Photo by ClearInnerVision

But the time has come to let go. We don’t have to micro-manage storage anymore, and we have much to gain by letting the array do the work:

• Just as traction control can manage each wheel independently, something a driver could never do, modern virtualized storage systems can allocate small “chunks” to the optimal drive type, creating a better layout than anyone could manage with LUNs
• Dynamic optimization technology can move these chunks around, adapting as loads change
• Thin provisioning can go a step further, not wasting drive capacity for unused space
• Wide striping and post-RAID storage systems have a higher threshold before performance suffers due to spindle hotspots
• Widespread availability of tiered storage, including advanced caches, solid state drives, high-performance SAS and FC, and cheap bulk disks, gives us many more options

As I mentioned, not all systems have these capabilities, and not all implementations are created equal. I’m concerned about misuse of thin provisioning, for example, but it’s hard to argue with its effectiveness in many circumstances. Find out how granular your system’s allocation is – some remain LUN-only, while others are much more effective, using tiny chunks.

These new storage automation technologies really become essential once high-dollar flash storage is added to the mix. If you’re paying 30 times more for a flash drive, you want to make sure you’re making the best use of it that you can! Look at IBM’s recently-announced SAN Volume Controller (SVC) and solid state drive (SSD) combination, for example: It will almost certainly have fine-grained thin provisioning of SSDs, and should be able to dynamically move data between flash and disk storage and even between different storage arrays, but I still have questions on how granular this capability will be. HDS can do similar things with their USP-V. NetApp’s V-Series NAS systems will do dynamic allocation, thin provisioning, and data deduplication to enable a better return on the flash drive investment. I’d love to see 3PAR, Compellent, Dell/EqualLogic, and HP/LeftHand apply their solid dynamic allocation tech to solid state storage as well!

Then there’s the 800 lb gorilla: EMC. More enterprise SSD has probably been shipped out of Hopkinton than every other vendor combined, and both the CX and DMX support (optional/expensive) “virtual provisioning” (aka, thin provisioning) of flash storage. But EMC’s Optimizer is not widely used, and only migrates entire LUNs based on user input – hardly the kind of dynamic and granular technology needed to optimally use all of that flash storage. I’m sure the company is working on addressing this issue, though. Perhaps it will appear in the DMX-5 announcement we are all expecting this year?

This article can also be found on Gestalt IT: How I Learned to Stop Worrying and Love Storage Automation

© sfoskett for Stephen Foskett, Pack Rat, 2009. | How I Learned to Stop Worrying and Love Storage Automation
This post was categorized as Enterprise storage, Gestalt IT, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

The Register did a nice job of summing up the (late 2008) flash positioning of the various storage companies, and I recently posted a strategic look at this core issue. Note that some, like HP and Sun (and probably IBM), seem to have an end-to-end strategy, while others are firmly in one camp or the other. In the “not yet” column, apparently, are 3PAR, BlueArc (though they offer TMS RAM), Dell/EqualLogic, HP/LeftHand.

Update: 3PAR has joined the “disk” camp.

It’s a Cache

Fusion-IO has rocketed to the forefront of the cache side with their PCI Express flash boards for servers. Joining them in this position are the following companies:

• HP (blades and servers)
• NetApp (PAM read cache card)
• Pillar (Slammer cache)
• Sun (read and write cache)

It’s a Disk

STEC is the darling of the flash-as-a-disk world, though Intel, Marvell, and Samsung are also playing here. Joining them in the corner are the following:

• EMC (STEC flash drives shipping the DMX now and CLARiiON in the future)
• Compellent (flash drives)
• HDS (flash drives in the USP-V)
• HP (flash drives in the MSA, perhaps, and maybe that Oracle thing)
• IBM (Fusion-IO storage behind SVC and standard flash drives in the DS5000)
• LSI (flash drives in the 7900)
• NetApp (ssd drives)
• Pillar (flash drives)
• Sun (flash drives in Thumper and JBOD)
• Xiotech (flash drives in the next Emprise canisters)
• 3PAR (flash drives in InServe)

So there you have it. It’s both a disk and a cache, depending on whether you sell servers or arrays apparently. If you sell both, it’s both. Simple!

If anyone wants to correct any of this, drop me a line or comment below!

See my posts on Gestalt IT for similar enterprise IT infrastructure commentary

© sfoskett for Stephen Foskett, Pack Rat, 2008. | Is Flash A Disk Or A Cache?
This post was categorized as Enterprise storage, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.