LUNs on a storage system represent the blobs of storage that are allocated to a server. A (VNX) storage admin creates a LUN on a RAID Group or Storage Pool and assigns it to a server. The server admin discovers this LUN, formats it, mounts it (or assigns a drive letter) and starts to use it. Storage 101. But there’s more to it than just carving out LUNs from a big pile of Terabytes. One important aspect is LUN ownership: which storage processor will process the I/O for that specific LUN?!
Once your Isilon cluster is up and running you’ll want to keep an eye on it. A piece of software that’s extremely useful to monitor both performance and capacity usage is InsightIQ. Very easy to set-up, it’s extremely powerful both in pro-active and reactive monitoring scenarios. Either sit back and watch the scheduled reports land in your mailbox or take a more active approach and drill down to find the source of a performance problem. Let’s explore further!
Earlier this month EMC announced the new VNX series which promises more performance and capacity at a lower cost per GB and a smaller footprint. The hashtag for the event was #Speed2Lead which was trending on Twitter during the official event and the weeks leading up to the Mega Launch in Milan, Italy. With performance being key in the new systems, the announcement was built around the Monza race track which had the Formula 1 circus in town. Guess what the logo for the launch was?
I myself was on summer holidays during the big event (ending up only a hundred miles away from Milan, albeit a week late ;)), so I couldn’t do much more than refresh twitter and get my timeline blasted to bits. So consider this a catch-up post!
In my previous posts I’ve discussed how to rack and stack your Isilon and how to get it powered up and running. With the Isilon systems operational it was time to put them into production and start the PACS data migration to Isilon. Which is actually easier than you might think!
When migrating servers from one storage system to another there are basically two options: Migrate using storage features like SAN Copy or MirrorView, or migrate using server based tools like PowerPath Migration Enabler Host Copy, VMware Storage VMotion or Robo Copy. Which option you choose depends on a lot of factors, including the environment you’re in, the amount of downtime you can afford, the amount of data, etc. I’ve grown especially fond of PowerPath Migration Enabler due to its ease of use. You can throttle its migration speed, your “old” data is left intact (so you’ve got a fallback) and once you’ve gotten use to the commands it’s child’s play to migrate non-disruptively and quickly.
I’ve treated myself to a shiny toy not too long after I started working in IT: a 2004 Honda VTR 1000 SP-2 (branded the RC51 in the US). It’s immense fun to ride and makes all the right noises when you twist your wrist. I’ve spent two summer holidays in the Alps on this bike and another three days on a race track in the south of France. With riding comes maintenance, something I enjoy doing myself. I’ve always had a fascination and curiosity with technology: if it makes a lot of noise, looks pretty and goes fast that’s even better. It’s a chance to get my fingers dirty, learn something new, assure myself it’s done correctly and save some money while I’m at it. A while ago I had to perform a valve clearance adjustment due to hitting the 30k km mark. A job that scares most people right from the start, but actually isn’t that hard if you pay attention. Read on to find out how to do it on a VTR SP-2 / RC51!
Yesterday we racked and stacked the EMC Isilon systems, prepared most of the cabling and pretty much prepared to start the Isilon systems. Which is pretty uneventful if you consider we’ve been dragging along hundreds of kilograms of equipment all day yesterday… The whole process can be pretty much split in four parts: configure the cluster and initial node, join the remaining nodes, configure the network, configure the rest.
I’m currently contracted by a customer that has been experiencing chronic capacity and performance issues in their storage environment. After analyzing the environment and writing an advisory report we got to work and started correcting and improving many aspects of the storage systems. One component of this overhaul is installing a pair of new Isilon systems which will store PACS (Picture Archiving and Communication System) data generated by the radiology department. The planning and design phase took place over the last couple of months, in which we involved both internal IT people and external resources such as the PACS vendor and the suppliers. All said, discussed and done: the actual implementation of the Isilon systems is scheduled for this week. Today: Isilon rack and stack!
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.
Recently I ran into an environment with a couple of VNX5700 systems that were attached to the front-end SAN switches with only two ports per storage processor. The customer was complaining: performance was OK most of the time but at some times during the day the performance was noticeably lower. Analysis revealed that the back-end was coping well with the workload (30-50% load on the disks and storage processors). The front-end ports were a bit (over)loaded and spewing QFULL errors. Time to cable in some extra ports and to rebalance the existing hosts over the new storage paths!