Tag Archives: VMware

Reclaim thin provisioned space in VMware datastore

We were using a portable storage array as temporary storage array to store data from an older array that had to be reconfigured. Capacity was quite an issue and everything would barely fit (with dedupe and compression doing its best on the Dell EMC XtremIO we were using for this), but we discovered that provisioned space wasn’t immediately reclaimed, so we got a bit into trouble when space wasn’t immediately reclaimed when data was deleted from a VMware version 5 datastore.

We were facing two options:

  • Datastore VMFS version 6: Unmap automatically every 12 hours (not 100% sure about this interval)
  • Datastore VMFS version 5: Unmap manually from the ESXi command line:

esxcli storage vmfs unmap -l XIO-05-VMFS-013

Read more »

How to enable SSH on a VMware 5.5 ESXi host using the vSphere client

virtual machine

Recently I needed to make some edits on vmdk files in order to get rid of a reference to the change tracking files, as mentioned in Gabrie’s post: Cannot open the disk and could not open change tracking file. An SSH connection to a VMware ESXi host was required. SHH was disabled and I needed to enable it temporarily.

How to enable SSH on an ESXi host using the vSphere client

In vSphere, select the host you want to enable SSH on.

Select the “Configuration” TAB, then “Security Profile”. In the upper right select “Properties.

A new window opens, now select SSH (you may need to scroll down a bit) and in the lower right select “Options”.

Again a new window opens and here you can either “Start” or “Stop” the SSH daemon.

enable SSH

Want to play around with VMware VVOLs? Here’s your chance! The Software Defined VNX is here!

Hard Drive

VMware now has this great new feature to be more in control of where its data blocks actually land on the storage system: VVOLs. But up until now EMC didn’t have a system capable of actually providing the back end for that. Until now I said. Starting with the VNXe 3200 all storage arrays are made vVOL capable and you can play around with that yourself. FOR FREE!

The Software Defined VNX is now a reality!

Read more »

Optimizing performance using VAAI and the ESX MaxHWTransferSize setting

xcopy transfer size

If you’re running an EMC VNX using a lower version than block OE version 05.32.000.5.209, you might want to upgrade to the latest and greatest version (patch 209 or newer). The 209 offers EMC’s latest fixes and enhancements for VAAI performance. Many of the found performance issues have been fixed in the 209 code. However, in some environments sub-optimal performance has been detected with xcopy operations, or in some cases with the performance of non-xcopy IO during xcopy operations to the same pool.

Read more »

How to translate Windows disk ids to storage array’s LUNs

Converting disk information in a VM into the actual LUN information

We’ve all been there: you have a certain Windows virtual machine with several disks of the same size and you don’t know which Windows-disk is in fact which storage LUN.

The VMware settings for this VM might look like this:

VM-config

Read more »