VSAN Part 23 – Why is my Storage Object Striped?

Those of you familiar with VSAN will know that one of the capabilities which can be placed in a VM Storage Policy is Number of Disk Stripes Per Object (stripe width for short). I covered this in an earlier post which looked at the various VSAN capabilities. Recently, a customer who had not specified a stripe width in the VM Storage Policy was perplexed to find that his storage objects had indeed been striped across a number of disks. He reached out to me if I could provide an explanation.

SolidFire demo: SIOC & QoS Interoperability

I watched a very cool demonstration this morning from the All Flash Array vendor, SolidFire. I spoke with SolidFire at the end of last year, and did a blog post about them here. One of the most interesting parts of our conversation last year was how SolidFire’s QoS feature and VMware’s Storage I/O Control (SIOC) feature could inter-operate. In a nutshell, QoS work at the  datastore/volume layer whereas SIOC deals with the VM/VMDK layer. Last week, Aaron Delp and Adam Carter of SolidFire did an introduction to QoS, both on vSphere and on the SolidFire system. And they also did…

Heads Up! VAAI UNMAP issues on EMC VMAX

We just got notification about a potential issue with the VAAI UNMAP primitive when used on EMC VMAX storage systems with Enginuity version 5876.159.102 or later. It seems that during an ESXi reboot, or during a device ATTACH operation, the ESXi may report corruption. The following is an overview of the details found in EMC KB 184320. Other symptoms include vCenter operations on virtual machines fail to complete and the following errors might be found in the VMkernel logs: WARNING: Res3: 6131: Invalid clusterNum: expected 2624, read 0 [type 1] Invalid totalResources 0 (cluster 0).[type 1] Invalid   nextFreeIdx 0…

vSphere 5.5, RDMs and Microsoft Clustering

I was having a conversation with one of our tech support guys (Greg Williams) recently about the relaxation on the requirement to allow Raw Device Mappings (RDMs) to be presented to different hosts using different SCSI identifiers and still do vMotion operations in vSphere 5.5. You can read that post here where I described how the restriction has been relaxed. Greg mentioned that he was handling a case where customers wished to share a physical mode/passthru  RDM between VMs on different ESXi hosts with a view to running Microsoft Clustering Services (MSCS) on top. We call this CAB or Clustering…

Heads Up! SW iSCSI, hostd and ESXi 5.5 U1 Driver Rollup ISO

My good pal Duco Jaspars pinged me earlier this week about an issue that was getting a lot of discussion in the VMware community. Duco also pointed me to a blog post by Andreas Peetz where he described the issue in detail here. The symptom is that the ESXi hostd process becomes unresponsive when software iSCSI is enabled. There is another symptom where an ESXi boot hangs after message “iscsi_vmk loaded successfully” or “vmkibft loaded successfully”. This has only been only observed with the ESXi 5.5 U1 Driver Rollup ISO. It has not been reported by customers using the standard…

VSAN Part 22 – Policy Compliance Status

I thought it might be useful to share some of the various VM Storage Policy status that I  have observed whilst testing Virtual SAN (VSAN). I’m sure this is by no means a complete list but as I said, these are the ones that I have come across and I am sure these are the status that you will observe most often too.

VSAN and vCenter Operations Interop

Continuing on my set of posts related to Virtual SAN (VSAN) interoperability, let’s take a look at how vCenter Operations Manager (vC Ops for short) integrates with Virtual SAN. vC Ops version 5.8, which was released in December 2013, recognizes the VSAN datastore and can report various characteristics, as you might expect. Although vC Ops 5.8 was released around 3 months before VSAN GA’ed, this release works with ESXi 5.5U1 and vCenter 5.5U1, the vSphere release which introduced VSAN. However, this release of vC Ops does not present all the ‘storage’ metrics for VSAN like it does for datastores based…