Category Archives: Configuration tuning hosts

Format of CSV on Hyper-V hosts is very slow

Hard Drive

When formatting a newly added disk (LUN) to Hyper-V, often you’ll notice the formatting takes forever. Dell EMC therefore advises to disable VAAI on VMware hosts for the same issue, however modern VMware hosts don’t seem to have this problem. Hyper-V however still have this issue. To disable the UNMAP / TRIM from happening, use the following command:

fsutil behavior set DisableDeleteNotify 1

After formatting was performed, you’ll need to re-enable UNMAP / TRIM by issuing the following command:

fsutil behavior set DisableDeleteNotify 0

 

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.

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Gridstore – Virtualization changes everything and nothing

GridStore

George Symons, Gridstore

Gridstore as a storage company is obviously focussing on SDS. Virtualization has changed the way storage vendors need to look at their storage solutions, because their storage now needs to react on how applications work to be able to provide an optimal performance. And of course cost. How customers want their storage solutions is about cost. It needs to be cheaper, perform better and provide more insight in what the data is actually doing there.

Virtualization changes everything and nothing

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Reaching USPEED – EMC Walhalla

It sure took me a while to read through the tons of performance related materials, but I admit that having done the Clariion IE Expert, Clariion TA and of course the latest VNX IE Expert and VNX TA Expert exams also helped. I got my invitation to join the USPEED gang a little over a year ago, in early 2013 and just like my fellow colleagues I was swamped in work and unable to even start reading through all the material.

During a beta I did for EMC in February ’14 I became interested again in actually getting that certification and all the goodies that come with it and I started reading and testing myself. For a test I just did the free VNX IE Specialist and Expert test exams as well as the TA specialist and expert exams: these are wonderful exams that can prepare you to actually enter the major league of storage gods (ahem).

EMC Walhalla!

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Migrating hosts to new storage ports, LIVE

Migrating hosts to new storage ports, LIVE!

Many SAN administrators will face this challenge from time to time: certain hosts need to start using new storage ports. Reasons vary, but in the EMC Clariion/VNX world this might happen because it’s decided to dedicate the mirrorview ports to mirrorview only instead of allowing hosts to use these ports as well. Obviously having dedicated replication ports will improve replication performance and for synchronous replication this will also improve the production host performance since the write acknowledgement from the remote array will be quicker and the extra latency is limited to a minimum.
So you end up wanting to free the SPA1 and SPB1 ports (most Clarrions) or SPA0 and SPB0 (VNX). But disalowing hosts to use these ports means they will loose access to these paths. This just might be disruptive! Or not?

There’s a way to migrate nondisruptively!

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VMware: “adaptive queue depth” setting

What is the recommended LUN queue depth throttling in VMware ESX/ESXi?

According to EMC this “adaptive queue depth” setting is not yet supported (June 2013). The full article can be found on this link. It is known as Primus solution id emc279718.

My advice would be not to use this setting until EMC certifies this setting for use with their arrays.

The exact Article is as follows:

What is the recommended LUN queue depth throttling in VMware ESX/ESXi?
 
  • Need to know QFullThreshold,QFullSampleSize & Queue Fulls values for VMware.
  • Host Connectivity Guide does not include any standard values.
  • Performance issues.
 
OS: VMware ESX / ESXi
Product: CLARiiON / Symmetrix and I assume VNX as well
 
According to Engineering, enabling the adaptive queue depth algorithm is NOT documented in the Host Connectivity Guide or the EMC Support Matrix.
The recommendation is to use the default setting which is disable adaptive queue depth.
Additional checks with E-Lab VMware quality engineers, E-Lab testing is done with the default setting.
 
See emc274169 for additional information and or changes.  Also see these two documents on support pages support.emc.com or Powerlink.Using EMC VNX Storage with VMware VsphereUsing EMC Clariion Storage with Vmware Vsphere & VMware Infracture Version 4.0