Re: SCSI Disk/Controller advice please - fun
hi ya
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
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
> I'm looking for advice on these: wich scsi controller should I buy?
> Software or Hardware RAID-1? Wich disk brand? (I'm getting a couple of
> 36GB, it is more than enough space for my setup)
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"
- 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
> 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
> Seagate Cheetah 10K 68 pin, 36Gb - 160 EUR
you're best bet
but even better if you use ide sisks ... 250GB disks for $150
or 40GB disk for $40 ... buy 4 disks ... why mirror to only 1 disk
>
> - Controllers
> Several Adaptec SCSI Cards from 200 to 400 EUR, wich can have:
> - 32 or 64bit
there is zero point in plugging an expensive 64-bit controller into a
32bit slot
> - 160MB or Ultra320
get ultra320 if you can ... and the ribbon cable to support that speed
get adapaptec ... all other scsi controllers are NOT on the radar screen
> - Raid (or not, when they say nothing.. I think) (the RAID ones start
> at 400 EUR and I've seen up to 950 EUR)
for that costs.. why is it an option ... you can build 1 or 2
whole/complete systems for redundant power supply, redundant motherboard,
redundant disks, redundant memory, etc, etc..
not just one disk mirrored to another disk on the same system
> Damn... Really confused... Please confirm these toughs also:
:-)
> UltraWideSCSI = 68 pin ...
> What is "2", "3" or "4" ?!? These seem
what sthe rest of the context ??
scsi-2 scsi-3 scsi-4?? ( i don't think scsi goes up that far)
> "similar" to ATA 66/100/133 - the bus speed, is that it?
yeah.. maybe .. depending on where you "2" and "3" came from
http://www.linux-1u.net/Disks/ata.gwif.html
http://www.linux-1u.net/Disks/scsi.gwif.html
> So, what's SCA? None of these controllers says SCA...
sca is the silly removable connector on the disk and in the chassis to
allow oyu to remove the disk
> Ps: I supose getting a SCSI crontroller built-in on the motherboard is
> stupid? Those are low-value/performance controllers?
onboard controllers are brain-dead and worthless
but its very good for teaching why you dont want to use it
vs getting an adaptec to lsi logic scsi controller if you insist on scsi
c ya
alvin
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