• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1702
  • Last Modified:

does the iscsi software adapter perform automatic rescans after a failuer to contact the initial datastore?

was wondering if my iSCSI software adapter performs an automatic rescan, after the failure of the initial LUN it was connected to
example- ESXi host in an ESXi cluster is connected to a SAN via iSCSI.
the SAN goes down which disconnects the iSCSI connection
will the ESXi host perform automatic rescans of the drive until it comes back up?
if so, is there a default interval?
0
jsctechy
Asked:
jsctechy
  • 4
  • 4
1 Solution
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Yes, when you iSCSI SAN is back up and online, the iSCSI Software adaptor will re-connect and re-scan for new LUNs.

it regularly polls the iSCSI SAN, check Advanced settings under iSCSI Targets for values.
0
 
jsctechyAuthor Commented:
thanks hanccocka
what would this be labeled as? RecoveryTimeout?
0
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
I would not recommend changing any of the iSCSI values, unless your SAN vendor has specific values you need to use for your SAN.

With ESXi 5.0 the iSCSI login timeout is currently set 5 seconds, this means that after 5 seconds the ESXi host kills the iSCSI session if there is no response, and tries to login again immediately after.
0
Improve Your Query Performance Tuning

In this FREE six-day email course, you'll learn from Janis Griffin, Database Performance Evangelist. She'll teach 12 steps that you can use to optimize your queries as much as possible and see measurable results in your work. Get started today!

 
jsctechyAuthor Commented:
thanks Hanccocka
im not looking to change the value of this but here is the situation-
we are doing testing on some equipment at our datacenter, and when we simulate a SAN failure and bring it back up, we want to know how long after we bring the SAN up the iSCSI connection will come back to the ESXi host.
what we have been doing is a manual rescan of the vmhba but we want to know if we should be waiting a couple minutes longer for it to rescan on its own
0
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
should be within a few seconds, off the SAN coming online.

we do not need to manually re-scan, if we take the SANs offline.

SAN failure is pull the power, wait 60 seconds, restart SAN!

ESXi should re-connect and datastores should be available, the moment the SAN is up and running.

we normally check with "ping".

what is the SAN?
0
 
jsctechyAuthor Commented:
gotcha- im not 100% they are working that way
they are hp lefthands
0
 
jsctechyAuthor Commented:
do you think its possible that this doesnt happen due to the type of SAN we have?
0
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Yes, I know the HP Lefthand SAN, the main cluster IP Address, should be available within seconds of it becoming online.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

  • 4
  • 4
Tackle projects and never again get stuck behind a technical roadblock.
Join Now