I've found jfs to be "fast enough", considering we are moving
from SQL-Server, no raw-disks on that one ( chuckles and laughs
allowed :-) . The risks that raw-disks present makes me wonder
if they are worth it. Restoring raw-disk databases presents its
own set of problems, whereas regular files can be backed up and
restored more simply and with more flexibility. After all is
said and done, we already see an increase in Linux over Windows,
so the expectations are different in our shop. Maybe in a situation
where you need to squeeze every bit of speed out of the system
are raw-disks worth it, only to have to live with the limitations
of having to restore the database in the event of a crash.
( Especially with Informix, the restore horror stories alone are
enought to scare me away from raw disks. And really, if you are
on a SAN, aren't you wasting your time with raw disks anyway? What
'raw' disk are you really accessing on a SAN? Having used raw
disks in the past vs using regular files at least from an
operational viewpoint I'd go with regular files any day of the
year. Perhaps good backups will offset the fear for now of anything
shitting our jfs drives until we hear of something better. JFS
is supposed to be improving too, to add data journaling along with
the metadata in the near future. It is also 'supposedly' the
lowest overhead file system, but every few months things change,
and of course the high priests of Reiser will soon come down from
heaven and release yet another version to mere mortals, so it looks
the game changes frequently. No matter, we'll back up the database,
then restore it to whatever file system is most appropriate, but
no raw disks for now, they're just not portable enough.
"Mark Bole" <makbo_at_pacbell.net> wrote in message news:3NHec.36245$az7.27185_at_newssvr29.news.prodigy.com...
> Jim Smith wrote:
>
> > Note the cross-posting - but no flame wars please.
> >
> > This question was prompted by a thread on the a postgres mailing list
> > during which someone (Gregory Williamson) claimed
> >
> > <quote>
> > raw devices, at least on Solaris, are about 10 times as fast as cooked
> > file systems for Informix.
> > <quote>
> >
> > This made me think about the old arguments, and I wondered about the
> > current state of thinking. Some of my knowledge will be a bit out of date.
> >
> [...]]
>
> I'm still trying to figure out why ext3 filesystem under Red Hat Linux
> seems to be *so* much faster than ufs under Solaris... even for simple
> OS utilities like "find" and "cp", let alone Oracle imports and bulk
> inserts. Is it the journaling? Or is it the five year old hardware? ;-)
>
> Is software RAID slower than hardware RAID, or not? (do a search on
> this... you'll see....).
>
> I haven't worked with an Oracle raw device since version 7.3 seven years
> ago, and would never go back. The administrative overhead is just too
> much of a headache. We have Veritas Quick I/O licensed in our shop, but
> we never implemented it in production because it turns out the database
> I/O has never even been close to being the bottleneck for our particular
> application... and as stated, your applicatino may be different.
>
> --Mark Bole
>
Received on Mon Apr 12 2004 - 21:32:56 CDT
