Re: Oracle and Veritas

On 10 Oct 1999, Philip Brown wrote:
> you are assuming he was refering to logging.
> He was not.

I was assuming you'd want to same features from UFS+ that you'd get from VxFS which includes logging.

> It should be obvious that ufs logging should NOT be turned on
> for filesystems that have databases on them.
> That's what the database transaction log is for.

When is the last time that a database transaction log improves mount time of a large filesystem for you? You still want filesystem logging on any large (>4 GB) filesystem, unless you think a 20 minute or longer boot time is acceptable on a production database system!?

If you really think it should still be turned off, and don't need to mount your filesystems quickly, then VxFS has one less advantage over UFS+.

> The only database-related filesytem improvement I'm aware of, is
> the "forcedirectio" option or someting.

Yeah, that's the UFS+ equivalent to Quick I/O. VxFS Quick I/O let's you do this on a per file basis. So you can have exceptional sequential and exceptional random performance on the same filesystem. Which doesn't really bring much of a benefit as you wouldn't usually want to configure sequential and random workloads to the same disk. But the option is there.

Regards,

Andrew Garman
Bluestone Consulting, inc. Received on Mon Oct 11 1999 - 18:29:05 CEST