VMware and I/O latency increased

Hello,

I use cluster VMware with 2 host connect by iSCSI to DSS V7, then I have 1 volume (about 14TB) attach iSCSI target. During backup virtual machine I see in log of vcenter this problem "I/O latency increased from average value....." increase upto 600000 microsecond sometime. This problem to little time. But come every time I try use storage with much work. Host connect to storage with 1Gb/s link each one, then storage has 1 link 1Gb/s dedicated to iSCSI.
I follow tuning vmware with iscsi on blog open-e but not change any. I haven't real problem but I think 600000 microsecond of latency is very high.
Can u give me some helps ? Thanks

M.

Configure for MPIO, and add more paths for more bandwidth.

Hello,

first all thanks to your reply, than I try found how I can create MPIO.... but not found.... how I can do it ?
Thanks

M.

This video will help you with MPIO and VMware.
http://www.open-e.com/service-and-su...ts-and-videos/

2012.07.17

http://www.open-e.com/site_media/the...011/ico_EN.png

Open-E DSS V6 iSCSI-Failover and MPIO with ESXi 5,0

Hello,

I follow your video, very well.... in my scenario I have only 1 dss (not replication), and on vmware host I have only 1 nic connect to dss. So I can use virtual address to have second patch ?? correct ??
I can create new vmkernel port on vm host with new ip address in new class where I put virtual ip.... so I have second path.... but it's only virtual path because physical is same....
Thanks

M.

It would be best to have 2 NICs as you will still be using 1 NIC even if you create another port on the same NIC. MPIO process is the same with or without replication.

without replication in DSS v7 i not found where i can create virtual ip ?

M.

This is correct as stated before the MPIO is only for showing how to set it up for the VMware side but you will need another NIC available for the MPIO to work and the VIP is not what you want as you are not doing any replication and the video focus was for the MPIO and not for the VIP w/ replication.

Ok, I understand... so I can do MPIO becouse I have only 1 nic, but why.... sometimes I have this latency... bandwidth not more 200/300Mb/s.... and I test connection and iSCSI use all gigabit.
Thanks

M.

[QUOTE=amatteo78;16226]Ok, I understand... so I can do MPIO becouse I have only 1 nic, but why.... sometimes I have this latency... bandwidth not more 200/300Mb/s.... and I test connection and iSCSI use all gigabit.
Thanks

M.[/QUOTE

I mean... that i can't do MPIO because i have only 1 nic.....