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IO Timeout value on Linux/HP-UX Servers connected to VPLEX LUNs
UNIX Admins:
Do you use a specific IO Timeout value on your Linux/HP-UX servers connected to VPLEX Luns? I have a bunch of UNIX/Linux Servers with Native Multipathing installed and another group of them have powerpath installed. Is there a recommended value that needs to be fine tuned for VPLEX devices - especially for IO Time-out value.
Regards,
-Kennedy
jespinoza1
52 Posts
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November 8th, 2012 12:00
Kennedy,
Hi! Linux timeout with multipath should be 10 seconds (30 without multipath) per the EMC Host Connectivity with Emulex Guide for Linux. You can set it lower but you risk instability and excessive trespass/failover operations. Setting it higher increases the amount of time we need to fail over in a multiple-paths-down scenario but generally is OK if the clients can tolerate it.
You need to locate the appropriate guide for your HBA and then look at the parameters. For instance, the table below is from the EMC Connectivity guide for Emulex and shows the parameter circled in red.
EMC Host Connectivity with Emulex Fibre Channel Host Bus Adapters (HBAs)
and Fibre Channel over Ethernet Converged Network Adapters (CNAs)
for the Linux Environments
Can be found on Powerlink here:
Home > Support > Technical Documentation and Advisories > Host Connectivity/HBAs > Installation/Configuration
Hope this helps.
Kennedy_Doss
79 Posts
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November 8th, 2012 13:00
Thanks a lot. This is exactly what I was looking for. I will have the Unix System Admins to look at the individual HBAs for this configuration. It sure does help - thanks for taking the time to work on this and getting back to me. I really appreciate it.
-KGD