by Liem Nguyen, Corporate Communications Manager — December 21, 2009
Here’s some light storage reading for whatever holiday you happen to be celebrating. Last week I got some questions from Phillip Jaenke, an IT consultant and Unix guy I “met” via Twitter @rootwyrm. He recently worked on a project for a customer of ours and got a little experience managing a Compellent SAN, which prompted him to ask some really detailed questions about our automated tiered storage technology. Since they were a bit too long for Twitter I thought I’d answer him via this blog. I asked Bob Fine, our director of product marketing to help tackle some of them.
Thanks to Phillip for his interest and for sending me these great questions. They are reproduced pretty much verbatim except in a couple places where I edited them for length. The result isn’t quite Click and Clack but you get the idea.
Look for future blogs and video conversations with Bob about storage technology trends. If you have questions or would like to send ideas for future posts, please contact me via email at lnguyen[at]compellent[dot]com or Twitter @LiemNguyen.
Q. With automated tiered storage, what level of control does an administrator have over the ATS behavior? For example, would I be able to control the number of hits on a block required to mark it as a 'hot' block for migration to the fastest tier?
BF: Although we do not provide control over the number of hits per block, we do provide a number of other options for control with Data Progression. These include locking specific volumes to a particular tier and control over how fast we move data between tiers. Our core algorithm moves the most active blocks to the highest tier allowed (also controlled by the admin) which is working well for our customers across multiple vertical markets.
Q. Am I able to control how long these blocks would stay on the fastest tier before migrating downward, and what level of granularity? For example, can I configure ATS so that a block needs to be hit 20 times in a 1 hour period to be flagged for migration to 15k disk, and once migrated, would only stay there for four hours when it drops below that hit rate?
BF: The system is taking into consideration the access patterns for all the blocks in a given volume, and the overall space available on any given tier, to make sophisticated decisions on where to best place the data. This decision is ongoing for the life of the block. You can adjust how long before the blocks move from the fastest tier to a slower tier through our profiles. Right now the options are for days not hours.
LN: The idea of managing the number of hits in a given hour is pretty cool, but the vast majority of customers that talk to us about tiered storage needs want something that’s a lot more “set it and forget it.” The reason they want it automated is they don’t want to mess with the different dials and levers.
BF: That being said, if a lot more customers want that level of control, we’d listen. We consult with our Compellent Customer Council (C3) and Enterprise Advisory Board on issues like next-gen automated tiered storage. What we hear from them is interest in expanding support for different drive types and I/O, not more manual intervention. But customers can definitely work with our Copilot team for some one-off scripting services if they really need even more granularity than we provide today, which is quite a lot already.
Q. Could I also configure ATS so that certain LUNs could skip tiers while migrating? For example, in a configuration with 15k FC, 10k FC, and SATA, could I configure a LUN that would only migrate between SATA and 15k FC, completely skipping the 10k FC tier?
LN: Yes, you can set a policy, or profile, to migrate a volume to a specific tier skipping intermediate tiers. This is customized in the Data Progression user interface.
Q. When a block is 'hot,' how are cache hits taken into account for managing these blocks? Would cache hits count as disk hits from the perspective of ATS, or does ATS only consider disk hits for migration measurements? To get a good bit more technical - is it possible to configure migration to also be based cache hit/miss rate, so that blocks sitting in cache constantly can be migrated to slower disk?
BF: Disk access is the primary factor for data movement, not cache hits/misses. What matters to customers most is disk access speed. Moving inactive data off expensive drives, or moving active data off slower rotating will have the most impact.
Q. Is the Storage Center management interface a separate server, or embedded in the controller? If it's embedded in the controller, is there some way for me to manage an environment with multiple controllers from a single point? (e.g. I have Compellent behind an SVC cluster, and have 3 smaller systems rather than one large one to increase performance further.)
LN: The browser-based management interface is embedded in the controller. All the typical storage admin tasks like mounting a LUN, mapping a server, executing a Replay (snapshot) can all handled via wizards. The design principle we used for the GUI was akin to TurboTax. If you can file your taxes online, you should be able to manage TBs of storage without special training or services.
The GUI makes managing storage for one server at a time pretty easy. For automating storage management tasks for hundreds of servers at time in Windows environments we’ve also integrated Microsoft’s PowerShell 2.0 cmdlets. For non-Windows users we also support a command utility for scripting.
You can manage multiple controllers and sites using a "single pane of glass" via our Enterprise Manager software, which is installed on a separate server. Some of the things you can do with Enterprise Manger are resource reporting across all sites (e.g. amount of SSD and SAS used), administering replication (including bandwidth shaping, live verification), administering chargeback, and creating handy charts that you can hand over to your CFO or CIO.
Q. Does Compellent provide an SMI-S for performance monitoring or array management? (Otherwise known as "can I hook it to IBM TotalStorage Productivity Center, BMC Patrol, Tivoli NetCool etcetera?") In a Tier0 / Telco environment, does it have alarm capability either through SNMP trap or dry contact?
LN: Yes, we support SMI-S 1.2 and SNMP traps. Our PhoneHome proactive monitoring also alerts the administrator of issues and admins can get prompted to do certain tasks like add more physical storage.
BF: We’re doing additional testing with SMI-S 1.4 on enterprise management frameworks from IBM, HP etc.
by Compellent Technologies, — June 15, 2009
On June 16th, Compellent will be participating in an exciting virtual trade show hosted by CIO discussing the benefits of virtualization and how it’s helped organizations cut costs, optimize resources and enable disaster recovery and business continuity.
During the event
Compellent CTO, Larry Aszmann, Burton Group analyst, Chris Wolf, and Compellent customers Tom Gonzales (Credit Union of Colorado) and Ping Ooi (Ares Management) will take part in a “Virtualization at Work” panel discussion. They will address ways virtualization can answer pressing budget questions, the current and future state of virtualization and cloud computing, industry trends and personal experiences with the technology.
The event will air live on Tuesday, June 16th, and be
available on demand from June 17 – September 17, 2009. All attendees who visit the event on June 16, 2009 may win an Apple® iPod touch® 8GB MP3 Player compliments of CIO.
Session Panelists Information:
- Vendor: Larry Aszmann, CTO, Compellent – Larry serves as the pacesetter for the panel discussion, speaking first on almost every topic and dictating the direction and tone of the panel.
- End User 1: Tom Gonzales, Credit Union of Colorado – Tom serves as the primary back-up for Larry, offering an end-user example to many of the points Larry initiates. Like usual, Tom does an excellent job discussing CUoC, while promoting Compellent.
- End User 2: Ping Ooi, Ares Management – Ping has a limited role throughout the first half of the discussion, but begins to speak more effectively towards the end. He seems to miss a few opportunities to discuss Compellent.
- Analyst: Chris Wolf, Burton Group – Chris seems to serve as the impartial participant, providing a general industry perspective. He often speaks for long periods of time without interruption.
CIO’s Virtualization Virtual Conference will provide a drill down into the trends shaping how CIOs are leveraging virtualization. It’ll look at wringing out the maximum cost savings; hidden benefits like green IT and disaster recovery; how virtualization is poised to push cloud computing past the tipping point; best practices for managing your virtual environment; Open Source Virtualization: Ready for Prime Time?; and virtualization and security: the critical issues confronting CIOs.
by Bob Fine, Director of Product Marketing — March 23, 2009
Today, we
announced plans to integrate STEC ZeusIOPS enterprise SSDs, offering intelligent SSD support to our customers. By coupling the drives with our block-level automated data tiering software, Data Progression, we allow users to keep only frequently accessed blocks of data on “tier 0” SSD storage and dynamically migrate inactive data to less expensive, lower tiers of storage. Customers can purchase drives in quantities of two or more and won’t have to dedicate entire volumes to SSD. In other words, we’re supporting SSD just like any other drive. This pay-as-you-grow approach can reduce overall costs and allow customers to more accurately plan SSD and other storage purchases.
The Register’s Chris Mellor wrote an
interesting piece on the news, highlighting our automated tiering, seamless integration and storage efficiency, which you can read
here. In contrast to other SSD offerings, Compellent’s virtualized storage makes it easy for multiple applications to simultaneously access the same SSDs on-demand, and the entire solution can be easily managed via Compellent’s single, intuitive interface. Additionally, Compellent’s persistent hardware architecture allows customers to plug these SSDs into their existing Compellent Fibre Channel enclosures and into production without requiring downtime or a rip-and-replace upgrade.
We will preview our SSD technology at
C-Drive 2009 (May 3 – 7, 2009) so if you haven’t registered yet, what are you waiting for?