Reliability of a system is usually expressed as a percentage of uptime. A system that has an uptime of at least 99,9% should typically not exceed an unplanned downtime of roughly 8 hours and 45 minutes each year. ‘Five nines’ or 99,999% of availability is often used in IT: this equates to roughly 5 minutes of downtime on a yearly basis. For Infinidat this wasn’t good enough, so they built the Infinibox with a reliability of 99,99999%. That’s only 3.2 seconds of downtime per year. Yikes!
A big change in the VNX2 hot spare policy compared to earlier VNX or CLARiiON models is the use of permanent hot spares. Whereas the earlier models would have dedicated, configured hot spares that would only be used during the drive failure, the VNX2 will use any eligible unused drive to spare to and NOT switch back to the original drive. I’ve written about this and other new VNX2 features but didn’t get to try it first hand yet. Until now: a drive died, yay! Continue reading to see how you can back-track which drive failed, which drive replaced it and how to move the drive back to the original physical location (should you want to).
In September 2013 EMC announced the new generation VNX with MCx technology (or VNX2). The main advantage of the new generation is a massive performance increase: with MCx technology the VNX2 can effectively use all the CPU cores available in the storage processors. Apart from a vast performance increase there’s also a boatload of new features: deduplication, active-active LUNs, smaller (256MB) chunks for FAST VP, persistent hotspares, etc. Read more about that in my previous post.
It took a while before I could get my hands on an actual VNX2 in the field. So when we needed two new VNX2 systems for a project, guess which resources I claimed to install them. Me, myself and I! Only to have a small heart attack upon unboxing the first VNX5400: someone stole my standby power supplies (SPS)!
XtremIO is the new all-flash array from EMC, announced not too long ago. Flash has an enormous performance advantage over traditional spinning disks. Although there are no moving parts in a solid state drive, they can still fail! Data on the XtremIO X-Brick will still need to be protected against one or multiple drive failures. In traditional arrays (or servers) this is done using RAID (Redundant Array of Independent Disks). We could simply use RAID in the XtremIO array, but SSDs behave fundamentally different compared to spinning disks. So while we’re at it, why not reinvent our approach of protecting data? This is where XtremIO XDP comes in.
Anyone working in IT knows that there are usually enormous amounts of whitepapers available to help you install, configure and run a new system or software suite. The fun more than doubles when the whitepapers start conflicting themselves. But even when they’re crystal clear, sometimes you run into a different problem: budget! With all planning and designing done, sometimes the budget or the purchased equipment does not allow you to follow ALL best practices to the letter, or at least make it a bit more challenging. In this example there’s the need to span a storage pool across DAE 0_0.
Yesterday I received a call about a drive failure in a CLARiiON CX3-80 storage array. Since every system has at least a couple of hot spares configured, usually this does not pose a problem. But this drive failure happened on drive position 0_0_0: a vault drive failure.
The vault drives host (amongst others) the operating system and configuration of the storage array. They are also used to destage the write cache in case of an event that might threaten data integrity.