Around The Block Blog
by Jim Lester, Product Specialist, Dell Compellent — June 29, 2011
With the release of Red Hat Enterprise Linux 6, Dell Compellent’s already great thin provisioning just got that much better. Thanks to the adaptation of new SCSI commands defined under the SBC-3 specification by the T10 Technical Committee, Dell Compellent Storage Center can now reclaim freed space from Red Hat systems. This is possible without any agent that has to be maintained, versioned and tested on each server.
Red Hat Enterprise Linux 6 introduced the SCSI UNMAP command to the ext4 file systems to support releasing space on SAN platforms that also implemented the UNMAP command. Compellent began working on implementing the UNMAP command early, recognizing the great value it could have with our thin provisioning. Starting with Storage Center 5.4 all the necessary pieces were in place to provide free space recovery to platforms like Red Hat 6.
Since this is all built in natively to the system, users don’t have to maintain a proprietary plug-in on every system deployed. All that is needed are the built-in tools.
Step-by-Step Guide on How to Use It
- Make a new ext4 file system and mount it using the new ‘discard’ option. This is the piece that tells Red Hat to send the SCSI UNMAP command to Storage Center when it is done with blocks of storage.
- Throw some files onto the new file system. Below is the screen shot from the Storage Center manager showing how much space has been allocated, about 24 GB.
- Compare that with the output from df. We can see that they are relatively close.
- Now for the magic, delete some data off the volume and look at the file system.
- We can see that the Storage Center has released the space back into the pool and is now only reserving about 15 GB of space.
This technology will allow customers to get even better efficiency out of their storage. Stop having stranded blocks allocated and not doing anything. This could also help increase the overall performance of the system as Dell Compellent’s other features like Fast Track and Data Progression can do an even better job of ensuring that the best performing space is utilized by real active data. All of this is achieved through native standards that don’t require the administrator to maintain any custom utilities on their servers. It just works, and that’s the way it should be.
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by Tim Plaud, Principal Storage Architect, Dell Compellent — October 12, 2010
My name is Tim Plaud and I'm a principal storage architect with Compellent, a partner of Intel. An evolving set of concepts for the better part of four decades, cloud computing has evolved from being a marketing buzz word with little clarity and even less credibility to a real IT strategy built on a set of proven technologies for data centers. Cloud computing now has a stronger-than-ever foothold and it only seems to be getting stronger.
Many end users I talk to understand the value of cloud services, whether the infrastructure to deliver IT as a service is built on-premises or owned by a service provider. However, the big issue for these companies is how they can go about architecting a solution. To help these companies build their own private clouds, we’re working with Intel and VMware to demonstrate a “Cloud on Wheels” solution in the Intel booth (#206) at SNW, taking place during expo hours on Tuesday, Oct. 12 and Wednesday, Oct. 13. Christian Black, researcher and architect, Intel IT, and I will be in Dallas to drive the demos and talk about how the different technology building blocks go together.
I’m excited to have worked with Intel and VMware on Cloud on Wheels, which will combine Intel Xeon 5600 processors, a converged IP/storage fabric on 10Gb iSCSI, VMware virtual servers and vSphere, and Compellent Fluid Data technology. The demo will illustrate how end users can experience the performance advantages of wide-striping and dynamic RAID, as well as the efficiency advantages of thin provisioning and automated tiered storage. In fact, automated tiered storage plays a particularly important role in this private cloud because application data always finds the right level of storage performance and capacity, without requiring any manual intervention. That’s critical for simplifying administration especially if organizations are tight on resources and don’t have a lot of time to manage storage.
Naturally, virtualized storage resources are just one piece of the private cloud puzzle. Cloud environments require the processing power, the virtual servers and the network connectivity to handle scalability, performance and management requirements. With Intel, VMware and Compellent technologies making up the foundation of the Cloud on Wheels solution, all the pieces work together in a self-tuning data center. Customers can manage large pools of IT resources, including networking, storage and servers, as part of an integrated modular, flexible and scalable cloud requiring very little management. After all, isn't that what this whole cloud thing is all about?
by Liem Nguyen, (former) Director of Communications and Social Media, Dell Storage — June 11, 2010
Five years is a long time in the storage industry. Five years ago, Compellent’s thin provisioning technology was a year old, and we introduced sub-LUN, block-level automated tiered storage to the world. Five years ago, Beth Pariseau, @PariseauTT, started covering the storage industry over at SearchStorage.com. That’s when Compellent first started working with her, offering our perspective on storage issues and connecting her with our customers across various industries, and we’ve enjoyed a great working relationship ever since. She was always willing to hear our point of view, and that means a lot to a growing company in this competitive market. Today Beth announced she’s moving on from the storage beat and will cover broader IT topics in the Data Center and Server Virtualization Group for TechTarget (the parent company to SearchStorage).
While I’m sure we’ll continue to share ideas on the role of storage virtualization in the data center, we’re going to miss regularly working with Beth. When I joined Compellent in 2007, I already knew of Beth’s reputation for balanced reporting, always digging at the story behind the story and never taking any vendor’s claims at face value. I first met Beth in person over dinner (Chinese) while at SNW Spring 2007 in San Diego. I found out that besides being a good reporter, she was a die-hard fan(atic) about all sports teams Boston, and we also compared notes about digital photography. She clearly knew more about ISO and F numbers than I did, and who was playing well or playing hurt. News briefings and phone calls since then have tended to include sideline discussions about the unimaginable life of Tom Brady or whether David Ortiz’s bat swing evoked fear or regret. Regrettably, I was supposed to take her to lunch last year but I broke my leg (playing touch football of all things) and had to take a raincheck.
Beth, the Compellent team wishes you all the best in your new role and thank you for sharing our passion for storage and sports. It’s been a fun and exciting journey for all of us as the market has changed so much over the past five years. We look forward to working with you on new stories, and also following you over @Cursed_to_First . Hopefully you and I will have that lunch soon.