Virtual SAN – free 6 month trial – thank you VMUG

vsan-vmware-virtual-san-boxA short post again today. For those of you who are considering evaluating Virtual SAN, our friends over at the VMware User Group (VMUG) are giving you the opportunity to trial VSAN for 6 months. This offer is only available to VMUG members, but joining VMUG is free. And really, if you are not already a member of your local VMUG, shame on you. This is a great way to get hands-on experience with VSAN. What are you waiting for? Click here to get your six month trial of VSAN.

VMUGOn the topic of VMUGs, I will be presenting on VMware’s Software Defined Storage initiatives at the Germany/Deutschland West VMUG User Conference in Frankfurt on June 17th, and again at the Poland/Polska VMUG in Warsaw on June 18th. Please sign up and support your local VMUG. If you are attending either of these VMUGs, I look forward to seeing you there.

Heads Up! Horizon View 6.1 and AF-VSAN Policies

I had a query recently from a partner who was deploying VMware Horizon View 6.1 on top of an all-flash VSAN 6.0. They had done all the due diligence with configuring the AF-VSAN appropriately, marking certain flash devices as capacity devices, and so on. The configuration looked something like this:

config.jpgThe they went ahead and deployed Horizon View 6.1, which they had done many times before on hybrid configurations. They were able to successfully deploy full clone pools on the AF-VSAN, but hit a strange issue when deploying linked clone pools (floating/dedicated). The clone virtual machine operation would fail with an “Insufficient disk space on datastore” error, similar to the following:

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A closer look at Rubrik

rubrik2A couple of months back, I wrote a short article on Rubrik. They were just coming out of stealth mode and had started an early access program. Since they had not officially launched, there wasn’t a lot that I was allowed to say about the company, other than give a high level overview. As they have now officially launched their r300 series of products, along with news of a massive $41 million Series B of funding, I can now share some additional details about their products and technology. Just to recap on what Rubrik do, they are offering a converged and scale-out backup software and backup storage appliance. The Rubrik appliance (Brik) is a “rack and go” architecture, with the ability to scale from three to thousands of nodes (unlimited) using industry standard 2U commodity appliance hardware.

The whole pitch is the idea that “backups suck”, and they want to give administrators a much better back and restore experience, similar to Apple’s ‘Time Machine’ feature.

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VAAI now available with vSphere Standard Edition

A short post today, but it highlights what I feel is an important enhancement to vSphere licensing. I’ve had lots of questions recently about why VAAI (Storage APIs for Array Integration) is not available in the standard edition of vSphere. This is especially true since I began posting about Virtual Volumes earlier this year, and it was clear that Virtual Volumes is available in the standard edition. One reason why this was confusing is that if a migration of a VVol could not be handled by the array using the VASA APIs, the migration would fall back to using VAAI offload primitives. But if you only had standard licensing for VVols, would you still be supported?

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vSphere 6.0 HA and Component Protection with vMSC

I had a query recently about changes to vSphere 6.0, especially when it comes to vSphere HA and Component Protection (VMCP) with vMSC, vSphere Metro Storage Cluster. The question is very straight forward – do all the same advanced setting recommendations for PDL and APD apply to vMSC on vSphere 6.0 as they did for vSphere 5.5? Or do we have some new recommendations now around PDL and APD for vMSC with the introduction of VMCP in vSphere 6.0?

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VSAN 6.0 Part 10 – 10% cache recommendation for AF-VSAN

AF-VSAN-BWith the release of VSAN 6.0, and the new all-flash configuration (AF-VSAN), I have received a number of queries around our 10% cache recommendation. The main query is, since AF-VSAN no longer requires a read cache, can we get away with a smaller write cache/buffer size?

Before getting into the cache sizing, it is probably worth beginning this post with an explanation about the caching algorithm changes between version 5.5 and 6.0. In VSAN 5.5, which came as a hybrid configuration only with a mixture of flash and spinning disk, cache behaved as both a write buffer (30%) and read cache (70%). If a read request was not satisfied by the cache, in other words there was a read cache miss, then the data block was retrieved from the capacity layer. This was an expensive operation, especially in terms of latency, so the guideline was to keep your working set in cache as much as possible. Since the majority of virtualized applications have a working set somewhere in the region of 10%, this was where the cache size recommendation of 10% came from. With hybrid, there is regular destaging of data blocks from write cache to spinning disk. This is a proximal algorithm, which looks to destage data blocks that are contiguous (adjacent to one another). This speeds up the destaging operations.

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vSphere 6.0 Storage Features Part 8: VAAI UNMAP changes

recycle2A few weeks, my good pal Cody Hosterman over at Pure Storage was experimenting with VAAI and discovered that he could successfully UNMAP blocks (reclaim) directly from a Guest OS in vSphere 6.0. VAAI are the vSphere APIs for Array Integration. Cody wrote about his findings here. Effectively, if you have deleted files within a Guest OS, and your VM is thinly provisioned, you can tell the array through this VAAI primitive that you are no longer using these blocks. This allows the array to reclaim them for other uses. I know a lot of you have been waiting for this functionality for some time. However Cody had a bunch of questions and reached out to me to see if I could provide some answers. After conversing with a number of engineers and product managers here at VMware, here are some of the answers to the questions that Cody asked.

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