Storage

Last week I attended the Virtualization Field Day 3 put on by the amazing staff at GestaltIT. One of the sessions was hosted by the folks at Atlantis Computing and they were giving us an overview of their Atlantis USX product. All travel expenses and incidentals were paid for by Gestalt IT to attend Virtual Field Day 3. This was the only compensation given. Atlantis USX Overview Before we get to the crux of the issue, a quick refresher on what Atlantis USX does. The USX product will utilize existing SAN, NAS and DAS and combine it with a server ram to do caching. The value proposition is that Atlantis USX can carve out RAM to be used as either a whole datastore (SUPER FAST) or combine it with existing storage and have it act as a cache. Keeping the cache so close to the processor without having to go across a bus or HBA, which can add additional latency, can be an important addition to a performance strapped storage solution. ...

If you are coming up on a storage refresh cycle soon, Pure Storage is worth taking a look at as your new storage array. I was fortunate enough to see them present their solution at Virtualization Field Day 3 this year and got a good look at their storage. All travel expenses and incidentals were paid for by Gestalt IT to attend Virtual Field Day 3. This was the only compensation given. ...

Good news for all of you eagerly awaiting the next iteration of the PernixData FVP software. Version 1.5 is now in Beta and you can request the download for your own testing from the following link http://info.pernixdata.com/Betaprogram. Disclosure: At the time of this writing I am a PernixPro which entitles me to early access to software, licenses or other merchandise. The thoughts expressed in this post are my own and have not been vetted by PernixData. ...

Microsoft has a new file system designed to increase data integrity, scalability and availability called the Resilient File System (ReFS). This file system has leveraged many of the NTFS file system goodies and expanded them to make it more scalable and prevent corruptions. ReFS was released with Server 2012 and at the moment is designed for use with file shares. It cannot be used as a boot volume at the present time, but this file system seems poised to replace NTFS down the road. ...

Microsoft Storage Spaces feature used to handle data redundancy, scalability and performance. Storage Spaces takes a set of Just a Bunch of Disks (JBOD) and pairs them together to allow for; either failures of a disk, gaining the performance of multiple spindles, or gaining the space of multiple disks. Traditionally this has all been handled by creating a Redundant Array of Independent Disks (RAID) group. Some examples of RAID would be: Striping (RAID 0) Mirroring (RAID 1) Parity (RAID 5 or 6) Storage Spaces create a similar type of RAID Group but then throw a virtual disk on top of them so that multiple types of stripes can be used on the same disks. For example, three physical disks can be put into a storage space. From there, three separate types of VDISKs can be created, Mirrored, Spanned and Parity can then be placed on the same set of disks with no issue. The diagram below shows an example. ...

I was fortunate enough to get to spend an hour with Dmitriy Sandler from Nimble Storage to see what all the fuss was about with their product and more specifically their Cache Accelerated Sequential Layout (CASL) File System. Hardware Overview Let’s cover some of the basics before we dive into CASL. The storage array comes fully loaded with all the bells and whistles, out of the box. All the software features are included with this iSCSI array and include items such as: ...

Solid State drives are much faster than their spinning disk predecessors, but can also have performance degradation due to how they interact with Operating Systems. Flash consists of blocks of data and those blocks are full of smaller items called pages. A typical SSD might have block sizes of 512KB and 4KB pages. There are 3 statuses that a healthy page could be in on a flash disk. Written to: Data from the OS has been written to the page. Unwritten to: The page is free and available to be written to by the Operation System. Invalid: The page has data in it, but is available to be overwritten by the Operating System. ...

I’m often asked about how to provision virtual machine disks. This almost always comes down to, “Should I use thick or thin disks?” and then “Should I do thin provisioning on the array or on the hypervisor?” So here we go: Thin vs Thick Thin provisioning: Thin provisioned disks don’t allocate all of the space during the provisioning of the storage. Instead, they allocate the space on demand. This is a great way to get more bang for you buck out of your storage. Let’s take a closer look with an example. ...

If you’re an engineer and you’re trying to get more experience with a variety of different storage devices, you might find yourself in a bit of a pickle. Most customers settle one one or two storage vendors and that’s it. So if you work for one of these companies you can learn EMC or Netapp, etc. I highly doubt your company would be interested in purchases a few different types of storage devices so that you can learn them as they are quite expensive. ...

Jumbo frames can be useful to optimize IP networks, especially in storage networking. This post should help to explain why using jumbo frames can be useful. I’m not Jumbo, I’m just big boned! First, let’s define what we mean by the term jumbo frame. As you can imagine it’s bigger than a normal frame. A Jumbo frame simply means any frame with an MTU larger than 1500 bytes. What exactly does that mean? To really understand that we need to look at an Ethernet frame. The diagram below shows a hastily thrown together Ethernet frame and most of the frame we’re not concerned with for this topic. Parts of the frame are used for determining where the frame is headed, where it came from and to make sure it arrived intact. The section we’re looking at is the “Data” or “Payload” section of the frame. ...