HP Tech Day – StoreServ Flash Optimizations

Attended HP Tech Field Day late last month in Disneyland. Must say the venue was the best ever for HP, and getting in on Nth Generation Conference was a plus. Sorry it has taken so long for me to get around to writing about it.

We spent a day going over HP’s new converged storage, software defined storage and other storage topics. HP has segmented the Software Defined Data Center (SDDC) storage requirements into cost optimized, Software Defined Storage and SLA optimized, Service Refined Storage. Under Software Defined storage they talked about their StoreVirtual product line which is an outgrowth of the Lefthand Networks VSA, first introduced in 2007. This June, they extended SDS to include their StoreOnce VSA product to go after SMB and ROBO backup storage requirements.

We also discussed some of HP’s OpenStack integration work to integrate current HP block storage into OpenStack Cinder. They discussed some of the integrations they plan for file and object store as well.

However what I mostly want to discuss in this post is the session discussing how HP StoreServ 3PAR had optimized their storage system for flash.

They showed an SPC-1 chart depicting various storage systems IOPs levels and response times as they ramped from 10% to 100% of their IOPS rate. StoreServ 3PAR’s latest entry showed a considerable band of IOPS (25K to over 250K) all within a sub-msec response time range. Which was pretty impressive since at the time no other storage systems seemed able to do this for their whole range of IOPS. (A more recent SPC-1 result from HDS with an all-flash VSP with Hitachi Accelerated Flash also was able to accomplish this [sub-msec response time throughout their whole benchmark], only in their case it reached over 600K IOPS – read about this in our latest performance report in our newsletter, sign up above right).

  • Adaptive Read – As I understood it, this changed the size of backend reads to match the size requested by the front end. For disk systems, one often sees that a host read of say 4KB often causes a read of 16KB from the backend, with the assumption that the host will request additional data after the block read off of disk and 90% of the time spent to do a disk read is getting the head to the correct track and once there it takes almost no effort to read more data. However with flash, there is no real effort to get to a proper location to read a block of flash data and as such, there is no advantage to reading more data than the host requests, because if they come back for more one can immediately read from the flash again.
  • Adaptive Write – Similar to adaptive read, adaptive write only writes the changed data to flash. So if a host writes a 4KB block then 4KB is written to flash. This doesn’t help much for RAID 5 because of parity updates but for RAID 1 (mirroring) this saves on flash writes which ultimately lengthens flash life.
  • Adaptive Offload (destage) – This changes the frequency of destaging or flushing cache depending on the level of write activity. Slower destaging allows written (dirty) data to accumulate in cache if there’s not much write activity going on, which means in RAID 5 parity may not need to be updated as one could potentially accumulate a whole stripe’s worth of data in cache. In low-activity situations such destaging could occur every 200 msecs. whereas with high write activity destaging could occur as fast as every 3 msecs.
  • Multi-tennant IO processing – For disk drives, with sequential reads, one wants the largest stripes possible (due to head positioning penalty) but for SSDs one wants the smallest stripe sizes possible. The other problem with large stripe sizes is that devices are busy during the longer sized IO while performing the stripe writes (and reads). StoreServ modified the stripe size for SSDs to be 32KB so that other IO activity need not have to wait as long to get their turn in the (IO device) queue. The other advantage is when one is doing SSD rebuilds, with a 32KB stripe size one can intersperse more IO activity for the devices involved in the rebuild without impacting rebuild performance.

Of course the other major advantage of HP StoreServ’s 3PAR architecture provides for Flash is its intrinsic wide striping that’s done across a storage pool. This way all the SSDs can be used optimally and equally to service customer IOs.

I am certain there were other optimizations HP made to support SSDs in StoreServ storage, but these are the ones they were willing to talk publicly about.

No mention of when Memristor SSDs were going to be available but stay tuned, HP let slip that sooner or later Memristor Flash storage will be in HP storage & servers.

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Photo Credits: (c) 2013 Silverton Consulting, Inc

A day and a half with HP Storage

A photo of bloggers and HP personnel waiting to go on the lab tour
Bloggers and HP people waiting to tour lab

[long post 945 wds] HP held their (annual?) HP Tech Days in Fort Collins, Colorado this last week. We had presentations from a number of HP product managers and got to meet a number of new and old bloggers there.

In attendance from the blogosphere were: Alastair Cooke (@DemitasseNZ), Brian Knudtson (@bknudtson), Howard Marks (@DeepStorageNet), John Obeto (@JohnObeto), Jeff Powers (@Geekazine), Rich Schandler (@recklessop), Derek Schauland (@webjunkie), Justin Vashisht (@3cVGuy), and Matt Vogt (@MattVogt).

Craig Nunes VP of Marketing, HP Storage got up and led off the day’s discussion talking about recent results. HP disk storage is up 11% for the quarter, 3par is growing by triple digit growth (QoQ maybe YoY?) and channel sales are growing by 10%.  HP storage is gaining market share, grew 3% for the quarter.  Also, HP is #2 is shipped backup appliances (1H11).  The current focus for HP storage is in three areas:

  • Invest in established platforms, MSA and EVA (with a 100K customers)
  • Invest in converged storage aimed at new data centers, 3PAR, Lefthand, IBRIX and StoreOnce.
  • Invest in converged systems knocking down barriers between servers, storage and networking with Virtual Systems.

Craig spent most of his time talking about converged storage. HP’s converged storage includes:

  • built in autonomic storage automating operations with one pain of glass and an orchestration layer on top to oversee everything.
  • scale out storage providing simpler ways to grow storage.
  • built on standardized platforms using off the shelf server platform technology

Craig ended up discussing HP’s Virtual System, their response to VCE’s Vblock, NetApp’s FlexPod and Dell’s vStart Bundle.   HP’s Virtual System was announced earlier last year and has been doing well in the market.

Brad Katz, Product Manager got up next and talked about Lefthand storage solutions.  Lefthand’s portfolio now ranges from the Virtual Storage Appliance (VSA) all the way up to a P4800 SAN storage blade with P4300 and P4500 rackmountable storage systems between those two.   Lefthand systems provide a clustered, scale-out IP/SAN and NAS storage.   Cluster data is striped across all disks in all storage nodes.

The VSA runs as a virtual machine and utilizes any ESX  (direct or SAN attached) storage.  The P4800 operates as a storage blade in an HP blade server and uses storage in the blade system.  The two rackmount systems P4300 and P4500 connect to SAS attached, external disk shelves.

HP's Steve Johnson, at the front of the room discussing slide on StoreOnce
Steve Johnson on StoreOnce

Steve Johnson and Mat Jacoby talked next about the StoreOnce deduplicating backup appliance product line.  StoreOnce is an HP R&D Labs home grown, deduplication technology which provides balanced ingest-restore rates and memory efficient deduplication.  The current product line spans D2D25xx, D2D41xx, D2D43xx and the recently announced, B6200 backup storage blade.

StoreOnce use a variable block, 4K chunksize and a sparse index which saves on server memory size which both lead to great deduplication rates.   Most deduplication functionality is memory intensive making it hard to scale without increasing memory or using different dedupe engines across a product line.  StoreOnce’s sparse indexing fixed that issue and as such, can use the same deduplication engine across their entire product line.

HP's JR (Jim Richardson) at the front of the room discussing 3PAR's advantages
JR talking about 3PAR advantages

Jim Richardson or JR, a 3PAR SE from the start, got up and discussed 3PAR.  Early on, 3PAR brought to the market three characteristics that differentiated it from other enterprise storage products:

  • Multi-tennancy – today’s cloud service providers and just about anyone running enterprise storage needs to support mixed workloads on shared storage. 3PAR’s ASIC allows data to be placed on any storage node and be serviced at direct access speeds to better support these multi-application environments. 
  • Thin provisioning – although certainly not the first to support thin provisioning (Iceberg was the first), 3PAR did much to popularize it.  Once again the ASIC provides automated support for thin provisioning.  
  • Autonomic functionality – optimization of storage performance across nodes and tiers of storage was also helped by their ASIC’s ability to transfer data without involving processor interaction.  Also 3PAR, tried to take the drudgery out of administration by automatically wide striping and making provisioning easier.

Jim Hankins and Chris Duffy came up next and talked about the X9000 IBRIX storage system.  Ibrix has intrinsic scale out NAS support and provides automatic failover across dual processing nodes called couplets. The B6200 backup system (see above) is based on Ibrix technology.  Ibrix supports a 15PB single name space that is segmented across cluster couplets.  Ibrix also comes in a gateway configuration using shared SAN storage behind it.

A picture of a X5000 without skins, and a couple of CRUs taken out
HP X5000 NAS system

Robert Thompson got up and talked about the X5000 Windows Server WSS based NAS product.  It is the industry’s first two node file system with active/active clustering in a box.  As the product runs Windows Server, one can run Anti-Virus or other server applications directly on the storage and is customer maintainable. Robert pulled out every replaceable unit in the system.  Apparently the E5000, HP Storage’s Exchange Appliance is also based on the same hardware.   The two servers in the storage system are clustered together using MSCS.

A photo of an intelligent data center floor tile with remotely controlled mechanical louvres to control air flow.
HPer showing off intelligent floor tiles

In the afternoon we went on a lab tour and got to see some of HP’s storage and data center cooling technology on display.

On the second day, Mike Koponen got up and discussed HP’s Virtual System (or Vblock competitor) and Aboubacar Diare gave some of his opinions on VMware VAAI & VASA integration from his testing perspective.  Finally, Calvin Zito wrapped up the two day event and everyone (except me and a few others) went on a brewery tour.

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All in all, we had a good time with HP.  Too bad, I didn’t get to go on the New Belgium Brewery tour, perhaps next time.

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