Solaris

Is it safe to mount all ufs slices with 'noatime' on SPARC Solaris 10 running Oracle database?

We have filesystems set up that way on an older server. This instance uses a lot of LARGE files. Oracle recommends zfs filesystems in some of the newer installation guides. Especially on Sol 10 branded zones running on a Solaris 11 global zone.

Did you read something that said not to mount noatime? Other than mounting noatime really does not help performance very much when you have few huge files held open forever.

This explains some things for you -
http://docs.oracle.com/cd/E19253-01/...t-3/index.html

thanks Jim,
I read somewhere that some backup scripts could use that feature by mistake.
anyway, I would like to use that option if it reduces hdd stress, they've been working 24/7 for years, and CPU load a bit.

Won't help worth noticing. Probably. Your best choice is to span physical disks (or on a SAN multiple luns). Example: each table space file is on a separate physical disk. Oracle definitely recommends this. The noatime tweak is a distant second.

Oracle also used to recommend the raw device approach - no formatted filesystem on versions like 9i. This is definitely faster as well because it removes some filesystem overhead. There are drawbacks as in all choices.

The atime is useful for diagnostics and cleanup. E.g. to decide if a certain file in /var/tmp is still in use.
Not important for the normal operations.
--
The performance junkees in kernel.org (Linux) decided to mount with a "reduced" atime setting by default.
So that a daily (or less frequent) file system cleanup is not distorted.

Best advice is to use Oracle ASM for Oracle database.

Put REDO in separate asm group on fast disks (SSD).

Other stuff (if using SAN) would be to use as much spindles needed for DATA and ARCH, as suggested, best is to measure the iops with iostat and determine the required physical disk count to achieve the desired response times/throughput.

For local disks things change a bit, depending on your setup, raid controller (if any) but the principle is the same.

Either add more spindles or 'fix' the code