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Author Topic: Fibre cards performance issue on AIX 5.3  (Read 5177 times)

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wganesh

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Fibre cards performance issue on AIX 5.3
« on: June 08, 2011, 06:35:12 AM »
Can anyone share some information on how the load balancing on Fiber cards works on AIX when there is EMC Symterix disks are connected to server?
We have AIX 5.3 TL9 SP2 installed on the server running with Oracle 10g. Having four FC cards (cards are dedicated) connected from the frame (p595).

See the lsdev output below, how can we achieve equal distribution of disks assigned to each card?

# lsdev -C | grep fcs
fcs0            Available 06-08         FC Adapter
fcs1            Available 0A-08         FC Adapter
fcs2            Available 0E-08         FC Adapter
fcs3            Available 0F-08         FC Adapter

# lsdev -Cc disk |grep 06-08 | grep Available | wc -l
      84
# lsdev -Cc disk |grep 0A-08 | grep Available | wc -l
     159
# lsdev -Cc disk |grep 0E-08 | grep Available | wc -l
      88
# lsdev -Cc disk |grep 0F-08 | grep Available | wc -l
      83

Also the nmon stats shows high utilization on fcs1.

Michael

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Re: Fibre cards performance issue on AIX 5.3
« Reply #1 on: June 09, 2011, 08:12:56 AM »
Load Balancing (aka multi-pathing) is dependent on several things.
First thought is the driver or PCM module used. Zoning or SAN design could also be a factor.

What does nmon show as adapter throughput (all 4 ports) when i/o is active? And if you take one of the disks listed and only have heavy load through that disk (test situation) are all 4 adapters busy? If not, then your configuration, for whatever reason, is not supporting multi-pathing.

And, what does lspath tell you?

p.s. If you are running 5.3 TL9 SP2 - which is quite "old", how are your firmware levels? Lastly, this is not a VIOS partition I assume (with the fiber adapters, but dedicated to the partition).
« Last Edit: June 09, 2011, 01:49:44 PM by Michael »