How long does your VMware MPIO multipathing failover typically take, in seconds?

[bear271]

How long does your VMware MPIO multipathing failover typically take, from the time you e.g. reboot a switch, till the sessions are re-established and the VMs resume?   My current configuration (Nimble NCM 3.0, ESXi 6.0, Nexus 3500 switches with recommended configuations) stuns VMs for ~30-40 seconds.  I know that this is technically well within VMware's spec to avoid crashing out the VMs, I'm just wondering if other customers get significantly shorter stun times in VMware iSCSI mpio failover scenarios......

[skrishna96 · Accepted solution]

Hi,

The path failover usually takes about 15-20 seconds. This is dependent on recovery_timeout value set with iSCSI adapter(10 seconds: but realistically it takes little longer than this value). If no other alternate paths are available to drive I/O, NMP will hold I/O's for 140 seconds (APD timeout) repeatedly retrying those I/O's. During controller fail-over it takes about 30-40 seconds for alternate controller to take over and resume I/O, depending on the number of volumes.

[root@c8-esx5:/opt] esxcli iscsi adapter list

Adapter  Driver     State   UID                                      Description          

-------  ---------  ------  ---------------------------------------  ----------------------

vmhba64  iscsi_vmk  online  iqn.1998-01.com.vmware:c8-esx5-3087acb8  iSCSI Software Adapter

[root@c8-esx5:/opt] esxcli iscsi adapter param get -A vmhba64

Name                  Current     Default     Min  Max       Settable  Inherit

--------------------  ----------  ----------  ---  --------  --------  -------

LoginTimeout                5           5           1    60            true    false

LogoutTimeout            15          15          0    60           false    false

NoopOutInterval         15          15          1    60            true    false

NoopOutTimeout        10          10          10   30            true    false

RecoveryTimeout       10          10          1    120           true    false

[bear271]

Sounds about right.   Fantastic!