[K12OSN] Onboard RAID or Software RAID

[Robert Arkiletian]

On 1/17/07, Dan Young <dyoung at mesd.k12.or.us> wrote:
> Krsnendu dasa wrote:
> > I am just not sure whether to use the RAID on the motherboard or
> > software RAID.
> > I know addon RAID cards (e.g . 3ware) have been recommended, but for now
> > I just want to use what I have.
> >
> > I have a motherboard with VIA VT8237 SATA RAID BIOS Ver 2.31
> >
> > In addition how do I monitor the disks. Basically, if one disk fails,
> > how will I know?
> >
> > What are the pluses and minuses of going with either option.
>
> http://linuxmafia.com/faq/Hardware/sata.html#via8237
> It's fakeraid, i.e. it relies on software drivers rather than hardware
> to provide RAID.

the via vt8237 doesn't even have NCQ (native command queing). But it
should do fine in a software raid using mdadm. Software raid 1 using
mdadm is robust.

>
> The dmraid driver might work; looks like work in progress.
> http://people.redhat.com/~heinzm/sw/dmraid/readme
> http://fedoraproject.org/wiki/DmraidStatus
>
> VIA apparently has proprietary RAID drivers, I tried to look deeper on
> their page but it made my eyes bleed:
> http://www.viaarena.com
>
> Software RAID (the md driver) works great. "cat /proc/mdstat" to see
> status; I think the mdadm tools come with a cron job to test the arrays
> and send you mail if the array degrades. Probably a winner if you want
> your stuff to actually work.
>

I didn't know mdadm could do this. This is how I get my system to
notify me of a failure.

1) edit /etc/mail/sendmail.mc find the smart_host line and set it to
your mail server
ex. smtp.mymailserver.net

2) again editing /etc/mail/sendmail.mc find masquarade_as and set your
mail server domain
ex. mymailserver.net

3) again editing /etc/mail/sendmail.mc enable feature(masquarade_envelope)

then issue this command as root on one line

m4  /usr/share/sendmail-cf/m4/cf.m4  /etc/mail/sendmail.mc  >
/etc/mail/sendmail.cf

then

service sendmail restart

then try this

echo "raid array dead  ." | mail -s "north server" someemail at somewhere.com

if it works then stick this into a cron one liner like this

3 21 * * *     grep  _  /proc/mdstat | grep -v read_ahead ; if [ $?
-eq 0 ]; then echo "raid array failure  ." | mail -s "my k12ltsp
server" someemail at somewhere.com

cool huh?!? BTW don't forget the "." in the end of the echo text
Beware: I haven't had a failure yet so I am not 100% sure it works. :)

-- 
Robert Arkiletian
Eric Hamber Secondary, Vancouver, Canada
Fl_TeacherTool http://www3.telus.net/public/robark/Fl_TeacherTool/
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