Re: SCSI Disk/Controller advice please - fun
Hi Alvin, thanks for the quick reply. Some comments and questions, tough:
Alvin Oga wrote:
On Sat, 30 Oct 2004, Joao Clemente wrote:
I'm getting a completly new server (P4 3Ghz, Dual-Channel DDR 400, MB
with intel chipset) and, while I have a good ideia on these components,
I would like to setup a RAID-1 system with SCSI disks...
there is zero point ot setting up raid-1 if you do not need
to be online 24x7
?!? What if a drive fails while on those 12h/day where people are
actually using them? This will be a fileserver where documents are
constantly changed/added/removed during the work hours!
problem with raid1 ( aka mirror )
- if one disk goes bad, the other disk will copy that bad info
onto the good disk .... the whole point of mirror, both disk
is identical
Well, I never used it before, I tought it was somewhat smarter... like
"mirror UNTIL a drive goes bad. At that point stop mirroring, ignore
failed drive, alert someone"
[...]
if you insist on using raid1 ...
do software raid1 so you can monitor it and maintain it
if you use hw raid1, you will suffer from not being able to monitor it
and at the mercy of the hw vendor to provide you
"monitoring/maintenance tools"
I see your point. Very good point!
- for the costs of the $200 hw raid1 controller, you can buy how
many additional disks to do your "mirroring" with rsync and tar
and other backup apps
How diferent is a "every minute" cronjob rsync'ing content in both
drives to RAID1 (regarding the problem you stated above): "bad info"
gets sync'ed to the good disk anyway... doesn't it?
Which are the tradeoffs of hard vs software raid1? What happens/How do
we proceed if 1 disk fails (how do we know it, how do we replace/resync
them?)
with raid1 .. you're gonna be S.O.L if one disk dies in a bad way
that will make the "good" disk also go bad
A drive failure may lock the whole disk array?
there is zero point in plugging an expensive 64-bit controller into a
32bit slot
:-) Stupid of me for asking this one... heheheh
Thanks
Joao Clemente
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