VMware ESX Server Optimization with EMC Celerra Performance Study TechNote

Question

FYI, for all of you that are using Celerra as VMware storage - a new TechNote was just released about performance tuning. see Powerlink in the category Home > Support > Technical Documentation and Advisories > Hardware/Platforms Documentation > Celerra Network Server > Technical Notes/Troubleshooting VMware ESX Server Optimization with EMC Celerra Performance Study Technical Note This technical note communicates the conclusions of a performance test effort to understand the performance of VMware ESX Server using storage provisioned from Celerra. This study assessed the impact of using Celerra uncached write and prefetch read performance-related options. This study also explored ESX Server configuration alternatives, such as virtual machine alignment, NFS buffer size tuning, and iSCSI initiator alternatives with ESX Server. http://powerlink.emc.com/km/live1/en_US/Offering_Technical/Technical_Documentation/300-006-724.pdf when you look at the graphs in the TechNote keep in mind that all values are relative and that for the reponse time values below 1 mean improvement whereas for bandwith values larger than 1 mean improvement. bottom line: NFS - Use the uncached mount option on Celerra file systems provisioned to the ESX Server as NAS datastore. This can improve the overall performance of the virtual machines. This should be considered particularly with random and mixed workloads that have write I/O. - When using random and mixed workloads without replication, consider disabling prefetch on the Celerra file system. This can improve the overall performance of virtual machines provisioned with Celerra NFS storage. - Do not align virtual machines that are provisioned with Celerra NFS storage because this may degrade the overall performance of the virtual machines. - consider adjusting the ESX Server¿s NFS buffer size depending on your workload ISCSI - Use the uncached mount option on Celerra file systems provisioned to the ESX Server as NAS datastore. This can improve the overall performance of the virtual machines. This should be considered particularly with random and mixed workloads that have write I/O. - Align virtual machines that are provisioned with Celerra iSCSI storage as it can improve the overall performance of the virtual machines. - Consider using an iSCSI HBA on the ESX Server with sequential workloads with Celerra iSCSI storage. This can improve the overall performance of virtual machines with such workloads.

silvam2BRA · Answer

Hi Rainer,

do you have any document about performance when using NFS on VMWare with Celerra ?

I am looking for something about NFS Threads. I have a case where 10 physical hosts were replcaed by 35 Vitual machines and performance was strongly miserable. We back to older server.

When using VMs we saw at nfs statistics and NFS Threads were on default limit 256

nasadmin@ns120-01 ~]$ server_stats server_2 -summary nfs

server_2 Total NFS NFS NFS Avg NFS NFS NFS Avg NFS

Timestamp NFS Read Read Read Size Write Write Write Size Active

Ops/s Ops/s KiB/s Bytes Ops/s KiB/s Bytes Threads

14:28:50 8717 4632 5193 1148 795 4476 5763 256

We are looking for some recomendation to increase or not the nthread on celerra side.

If you have any documents will be much apreciatted.

Thanks

Celerra

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