Re: [GENERAL] server hardware recommendations (the archives aredead)

Jeff Hoffmann wrote:

> Ed Loehr wrote:
> > Jeff Hoffman wrote:
> >
> > > ...i have seen several places which told me
> > > that software raid under linux _isn't_ safe for multiprocessors & no
> > > place has told me for sure that it is.
> >
> > Would you mind clarifying your understanding on which versions of linux are unsafe
> > for software raid and how? Browsing deja, RH 6.1 (2.2.12-20smp) reportedly handles
> > software raid without known problems (other than less than glowing documentation
> > reviews), and I'm setting up pgsql/apache on such a system with software raid (no
> > clear showstopping problems yet).
>
> i'm not running RH6.1, but i am using a 2.2.12 kernel (compiled myself)
> and like i said, no catastrophic problems. the problems, i believe,
> came up with a conversation about an earlier 2.2 version of the kernel
> and it may have included problems with adaptec SCSI controllers in
> conjunction with software raid on SMP systems. i don't remember where i
> found the references, though. i believe the adaptec 7880 driver was
> fixed by 2.2.10, and there were a bunch of SMP fixes between 2.2.6 -
> 2.2.10, so 2.2.12 is probably as safe as anything. you never hear about
> things that work, just about things that don't.

I can confirm the problems with the Adaptec controller on kernels such as 2.2.5 (RedHat
6.0) - regardless of whether or not you're running SMP. We lost data on a non-SMP box
using the Adaptec 2940U2W LVD controller with 2.2.5. Our first move was to shut off RAID
1. I sent Doug Ledford a note on the issue (as I'm sure thousands have...), and have
since upgraded to 2.2.9 and have run without problems....so far. The Adaptec controllers
appear to be the controllers to avoid.

Mike Mascari