Our ESXi hosts have always been slow booting when it came to iscsi_vmk loaded successfully - sitting here for almost 5 minutes.

In all a full server reboot takes almost 12 minutes.

We have 9 iSCSI targets per host (5 SANs with redundant interfaces) configured as dynamic discovery targets.

Has anyone experienced this? Can it be remedied with static discovery mode? Are there any debug steps we can work through to help diagnose this?

(All our targets are accessible at boot so i'm assuming the host isn't stuck retrying to connect to a target)

  • Have you tried setting the hosts to static discovery to see what effect that has? – joeqwerty Jun 4 '14 at 15:22
  • I haven't but i've got a host down for maintenance at the moment so I can do some testing, however this shouldn't cause this problem if all targets are discoverable? – Myles Gray Jun 4 '14 at 15:24
  • Hmmm... just found this. Maybe it's relevant - kb.vmware.com/selfservice/microsites/… – joeqwerty Jun 4 '14 at 15:29
  • Are the targets all used as datastores, or are any of them for physical-mode RDMs? – techieb0y Jun 5 '14 at 3:05
  • Targets are all datastores, no RDMs – Myles Gray Jun 5 '14 at 9:21

Coming back to this, reconfigured hosts with Static Targets instead of Dynamic Targets took the time stuck on "iscsi_vmk loaded successfully" from 10 minutes to 15 seconds.

  • Interesting, what kind of SAN was this? – SpacemanSpiff Jun 10 '14 at 14:39
  • Some old Dell MD3000i's - been like that since they were installed years ago – Myles Gray Jun 10 '14 at 18:26
  • What ESXi version are you running? I vaguely remember a patch that fixed this with dynamic targets against certain SAN's. We were effected as well, but it went away. – pauska Jun 10 '14 at 21:59
  • It was version 5.1 the patch was released in but we are running 5.5 all round – Myles Gray Jun 11 '14 at 7:05

Confirm your iscsi networking is configured correctly, eg) multiple subnets as recommended by the storage vendor, properly configured "zoning" allowing the ESXi iscsi interfaces access to the correct array interfaces.

Also check the vmware host logs, they'll squawk if they're having connection problems.

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