Re: [PERFORM] Quad processor options

On Wed, 12 May 2004, Grega Bremec wrote:

> ...and on Tue, May 11, 2004 at 03:02:24PM -0600, scott.marlowe used the keyboard:
> >
> > If you get the LSI megaraid, make sure you're running the latest megaraid
> > 2 driver, not the older, slower 1.18 series. If you are running linux,
> > look for the dkms packaged version. dkms, (Dynamic Kernel Module System)
> > automagically compiles and installs source rpms for drivers when you
> > install them, and configures the machine to use them to boot up. Most
> > drivers seem to be slowly headed that way in the linux universe, and I
> > really like the simplicity and power of dkms.
> >
>
> Hi,
>
> Given the fact LSI MegaRAID seems to be a popular solution around here, and
> many of you folx use Linux as well, I thought sharing this piece of info
> might be of use.
>
> Running v2 megaraid driver on a 2.4 kernel is actually not a good idea _at_
> _all_, as it will silently corrupt your data in the event of a disk failure.
>
> Sorry to have to say so, but we tested it (on kernels up to 2.4.25, not sure
> about 2.4.26 yet) and it comes out it doesn't do hotswap the way it should.
>
> Somehow the replaced disk drives are not _really_ added to the array, which
> continues to work in degraded mode for a while and (even worse than that)
> then starts to think the replaced disk is in order without actually having
> resynced it, thus beginning to issue writes to non-existant areas of it.
>
> The 2.6 megaraid driver indeed seems to be a merged version of the above
> driver and the old one, giving both improved performance and correct
> functionality in the event of a hotswap taking place.

This doesn't make any sense to me, since the hot swapping is handled by
the card autonomously. I also tested it with a hot spare and pulled one
drive and it worked fine during our acceptance testing.

However, I've got a hot spare machine I can test on, so I'll try it again
and see if I can make it fail.

when testing it, was the problem present in certain RAID configurations or
only one type or what? I'm curious to try and reproduce this problem,
since I've never heard of it before.

Also, what firmware version were those megaraid cards, ours is fairly
new, as we got it at the beginning of this year, and I'm wondering if it
is a firmware issue.