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Re: hard- or software-raid?

There is perhaps one extra thing hardware RAID will give you. When it comes to hardware failures a Hardware RAID card will almost always detect a failed (or failing) drive before any software based system would. In fact I've seen a RAID card detect a failed drive before the HDD manufacturers own Disk Diagnostic software, and they were happy to replace it based on my RAID cards diagnosis.


At 10:26 24/01/2003 +0100, Tinus Nijmeijers wrote:
My question kind'a stands: If the only thing I ask of it is for the data
to be safe (no speed or "no downtime!" issues) is there any reason to
use hardware over software raid?

I do not care if I have to take the server down for an hour (or 2, or 3)
to replace a disk, be it a raid disk or boot disk. I have plenty of
time, I could even run down to the store, get a new bootdisk, install
debian and be up and running in 2 hours. no problem.

ONLY thing that is important is that the data needs to be safe. if 2 of
the raid-disks fail I need the data to be safe.

(it is, of course, a budget thing. In case of fire I have tapes to get
the data back, there's downtime involved there. So I do care about
downtime. Just that with disks being as cheap as they are I was thinking
that a software raid is soooo cheap to build that maybe that's worth the
extra cash for the 3 extra disks that I need to buy.

scenario 1: boot of scsi, data is on a 200G IDE, tape backup

scenario 2: boot of scsi, data on 4x80G IDE (software-raid5), tape
backup  = + EURO 100

scenario 3: boot of scsi, data on 4x80G IDE (hardware-raid5), tape
backup = + EURO 500

scenario 4: boot of scsi, data on 4x80G SCSI (hardware-raid5), tape
backup = + EURO 2200

so for close to nothing (E 100) extra I get software raid.

Is hardware raid "safer"?

(I do not think it is, I'm just waiting for someone to tell me I'm being
naive here)


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