Datrium go GA

datriumThis week Datrium announced that their DVX system is now generally available. I met these guys at VMworld 2015, and wrote a closer look at Datrium here. If you want a deeper dive into their solution, please read that post. But in a nutshell, their solution uses a combination of host side flash devices to accelerate read I/O, while at the same time writing to the Datrium hardware storage appliance (called a NetShelf). The NetShelf provides “cheap, durable storage that is easy to manage”. The DVX architecture presents the combined local cache/flash devices and NetShelf as a single shared NFS v3 datastore to your ESXi hosts.

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VSAN Stretched Cluster – some possible warnings

vsan_stretch_graphic_v02_300dpi_01_square140We are hearing about a number of VSAN stretched cluster implementations going on at the moment, which is great news. I just set up such a configuration once again in my lab as we look at some various scenarios for the next release of VSAN. Now, for anyone looking at implementing VSAN stretched cluster, there is the VSAN 6.1 stretched cluster guide which should be your first port of call. However I noticed that once VSAN stretched cluster is implemented, you get a few warnings that you typically wouldn’t see in standard VSAN deployments. That is what I want to call out here.

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Where are they now? Recent changes in the storage space

watnThe storage space has been a very exciting space over recent years. There have been so many new start-ups and new innovations, that it becomes difficult to keep track sometimes. More recently, there has been a lot of news around mergers, acquisitions and IPOs in the storage industry. It got me thinking about a lot of the changes we have seen over the past 3-4 years in the storage market. Just for my own interest, I went back over many of my blogs, and the various conversations I had with people at various VMworld events and VMUG meetings, and tried to see where a lot of these companies/products are now, and what they are currently doing. Now, I am not going to mention every single vendor here. I’m simply trying to highlight the ones that were acquired or merged or indeed IPO’ed (and in some cases are no longer with us) during this period.

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Snapshot Consolidation changes in vSphere 6.0

This is something I only learnt about very recently, and something I was unaware of. It seems that we have made a major improvement to the way we do snapshot consolidation in vSphere 6.0. Many of you will be aware of the fact that when they VM is very busy, snapshot consolidation may need to go through multiple iterations before we can successfully complete the consolidation/roll-up operation. In fact, there are situations where the snapshot consolidation operation could even fail if there is too much I/O.

What we did previously is used a helper snapshot, and redirected all the new I/Os to this helper snapshot while we consolidated the original chain. Once the original chain is consolidated, we then did a calculation to see how long it would take to consolidate the helper snapshot. It could be that this helper snapshot has grown considerably during the consolidate operation. If the time to consolidate the helper is within a certain time-frame (12 seconds), we stunned the VM and consolidated the helper snapshot into the base disk. If it was outside the acceptable time-frame, then we repeated the process (new helper snapshot while we consolidated original helper snapshot) until the helper could be committed to the base disk within the acceptable time-frame.

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VSAN.ClomMaxComponentSizeGB explained

In the VSAN Troubleshooting Reference Manual, the following description of VSAN.ClomMaxComponentSizeGB is provided:

By default VSAN.ClomMaxComponentSizeGB is set to 255GB. When Virtual SAN stores virtual machine objects, it creates components whose default size does not exceed 255 GB. If you use physical disks that are smaller than 255GB, then you might see errors similar to the following when you try to deploy a virtual machine:

There is no more space for virtual disk XX. You might be able to continue this session by freeing disk space on the relevant volume and clicking retry.

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Losing the VASA Provider and/or vCenter Server in VVols

VVolsWith the release of vSphere 6.0 earlier this year, VMware introduced the eagerly anticipated VVols or Virtual Volumes. As we see more and more traction around VVols, a specific question has come up a number of times already. The question is basically: “What happens to VVols if I lose my VASA Provider or my vCenter Server, or indeed both of these components? Will I still have access to my devices?”.

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A new vRealize Log Insight Content Pack for VSAN

loginsight-logoAttention VSAN users. A new Log Insight content pack has just been released specifically for Virtual SAN. For those of you not familiar with Log Insight, this product does automated log management through log analytics, aggregation and search. It allows administrators to analyze terabytes of logs, perform smart parsing to discover structure in unstructured data, and enable interactive, real-time search and analytics through a GUI-based, easy to use interface.

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