Monday, June 25, 2012

Slow NFS mount

We were installing AdminServer on NFS as per EDG and we found it was taking more than 20 minutes to restart the server. It all pointed toward NFS slowness, upon looking more closely on /etc/fstab, we found the root cause:

/nfs/app/oracle nfs rw,bg,hard,nolock,intr,timeo=600,wsize=32768,rsize=32768,nfsvers=3,tcp,actimeo=0 0 0

Pretty much all parameters were fine except acttimeo. This parameters determines the caching for file attributes and seems like WebLogic server start-up was slowing down because of no caching. Removing this attribute from nfs mount solved the issue with slow startup. We cut down 20 minute boot up time to 2 minute. New settings:
/nfs/app/oracle nfs rw,bg,hard,nolock,intr,timeo=600,wsize=32768,rsize=32768,nfsvers=3,tcp

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