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VSA / ESXi performance tuning

Occasional Visitor

VSA / ESXi performance tuning



We've fairly recently deployed HP DL380s with SmartArray P420i controllers and VSAs running under ESXi 5.1.  We'd been seeing behaviours similar to those reported by others in this forum relating to occasional clagging aparrently due to the IO queue exceeding the physical hardware capabilities as we migrated more VMs to this environment.


We've resolved these issues (currently QAing the results) by setting non-default value for various parameters under ESXi for both the hardware controllers and for the iSCSI adapter:


   - P420i Hardware Controller:

      - queue depth 32 -> 4

      - Max IO 32MB -> 2MB

   - iSCSI adapter:

      - queue depth 128 -> 16


This is a bit of a big stick approach, however we'd like to apply a little more finesse to the selection of the value for these parameters.  Are there published guidelines available for these settings?


What's worked for you?


Many thanks...

Valued Contributor

Re: VSA / ESXi performance tuning

1. Use HP SAAP 2.0 and add an SSD to read only caching - any drive works - faster the better. 750gb max for 1GB FBWC, 1.5TB for 2GB FBWC model! HUGE performance gains (reading!)




Get an ADAPTEC maxcache series or LSI megaraid 9271 with cachecade 2.0 (write back and read caching!)


Write back caching with proper drives allows massive bursting since all writes go to ssd first.


Read back caching (HP SMARTCACHE) is read only and will help with reading only but it does help a lot! And it is much safer.


Either way, do it!


Remember each lun has its own queue depth, so if you have 10 luns, you can push it deeper in queue depth.




use all SSD! and 10gbe nic and really watch it fly!


the S3500 intel are very cheap and don't require overprovisioning like other consumer drives! 7% !! for every other consumer drive you need about 30%. IE Samsung 840 PRO 256gb, only use 192gb. 512gb only use 384gb.


Also start with 1 switch (10gbe) , no flow control, and 1 storage unit to baseline! compare ESXI delayed ACK option (!!) and make sure you have all tweaks for your nic card in place so it can use each core to dispatch i/o. ALSO one VM per VMHOST max to start!



SSD caching will help microbursting.


We have one : DL380 G7 with P420/1gb fbwc (unsupported solution) is very powerful, adding a second p420/1gb FBWC  even more powerful! 


Then the $399 DL180 G6 with dual 6-core L5639 makes a good runner up but it is LAN limited to gigabit due to the 14LFF cage. but the price is awesome.


Only reasont the P420 is unsupported for the G6/G7 is due to weak heatsink design and thermal dissipation but that can be fixed with some engineering (artic silver, fans, better heatsink/heatpump/watercooling) but again its unsupported!


The LSI megaraid and adaptec maxcache support write back caching which massively increase write bursting however it requires heavy duty ssd drives (SLC).


IMO for the VSA, I would work on increasing your local IOPS rather than limiting them!


Given the cheap used prices, you can't beat it! google "L5639" they work in all G6/G7 HP high end servers! (dl180/dl160/dl320/dl360/dl380).


Also remember those servers have one pci-e bus for both sockets, only a few servers have two bus with 2 sockets (ml370  iirc). This allows far more expansion.


The fastest server we have seen was the DL585 with 4 SOCKETS, and 4 BUS you can have 11 RAID controllers in one box!


Why? To run DEV/PROD on the same machine!


You can two VSA on one server, saving energy! or Three! or four!


Then stripe more units for nraid (2 boxes) or nraid-5(3 boxes) etc.


Also you can run light vm's on the same machine which in a 2-box scenario will have a 50% hit rate on reading from local VSA!!


VSA is cool you can bend the rules since its your own solution!


Can you imagine a DL380 G6 with optional riser, $599 dual l5639, 24gb of 1333 ram.

$85 used for 8sff cage, $269 for P420/1g FBWC, $269 for P420/1gb FBWC, $500 for 480gb S3500 * 16, $269 for SAAP 2.0 key for hp smartcache! $99 for Be2 emulex dual SFP nic (buy two!)


P4900 will lose to this! all day long.


Compare the price! used VSA will smoke the highest performance HP P4900 lefthand! for less than $12K a unit!!



Edmund White
Frequent Advisor

Re: VSA / ESXi performance tuning

This is interesting. I have an option to be able to use Fusion-io cards for some DL380p Gen8's. Would this be a viable VSA platform under ESXi, or should I just stick with the Enterprise SSDs and a P420i? 

Re: VSA / ESXi performance tuning



For P4000 SAN solutions querries you can also visit the HP Guided troubleshooting tree.


Below is the link for HPGT:


I work for HP


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