disabling write cache in fstab?

[George N]

Hello, we have an EMC disk array that has many GB of cache memory built into it. We were told that we should edit /etc/fstab and disable the operating system's write cache for our SAN volumes and let the disk array do all the caching. I did some searching and couldn't find the options to do this. Does somebody know the fstab mount option to disable write caching? (In Linux the option is "sync" which causes purely synchronous writes to that volume.) Thank you.

[James R. Ferguson · Accepted solution]

Hi George:

First, you need to have (for lots of reasons) OnlineJFS.

Then use mount options to include:

mincache=direct,convosync=direct

Regards!

...JRF...

[George N]

Perfect, thank you! I'm running HP-UX 11.31 (virtual server oe) on an rx6600. Would this have OnlineJFS installed by default? Or is this something I need to go and research?

[James R. Ferguson]

Hi (again):

With 11.31's VSE-OE you already have OnlineJFS:

http://h71028.www7.hp.com/enterprise/w1/en/os/hpux11i-oe-options.html

Regards!

...JRF...