fstab entries help

[shruti_1]

Has anyone used delaylog, nodatainlog and log,nolog on HP-UX filesystems.? What are the
advantages and disadvantages of this mount options for oracle?

[Darrel Louis]

Hi,

Read the following document:
http://h21007.www2.hp.com/dspp/files/unprotected/database/HP3KOracle.ppt

Is the server connected to a SAN?

For best performance, it is wise to have the Online (advanced) JFS product. Using it, you can better manipulate specific mount options and adjust for performance (see man-pages for fsadm_vxfs and mount_vxfs).

In general, for VxFS filesystems use these mount options:
delaylog, nodatainlog

For VxFS filesystems with primarily sequential access, use:
mincache=direct, convosync=direct

Darrel

[David de Beer]

Morning,

Yes, we use these options everyday - if I was in your position I would not use ASYNC mode for an oracle filesystem.

ASYNC = tmplog,largefiles,mincache=tmpcache,convosync=delay

This is very fast, but unsafe - the machine will tell the application that the data has been written to disk, when it is actually still in cache waiting to be written to disk.

SYNC =
I you want a safe (but slow!) filesystem, I would not use anything more than - log (and always largefiles)

Look here for a complete explanation:
http://docs.hp.com/en/B3929-90011/ch05s04.html

Regards,
David.