RAID: question about identical hard drives

I am shopping for a good RAID 5 solution for network storage. I have
several candidates in mind, most of which are traditional RAID5
solutions (Drobo is not, different story).

How identical do hard drives need to be for a RAID when replacing one at
a time? If I buy 4 Seagate, 500Gb, 7200 rpm drives now, they have a
5-year warranty. When one of them dies in 5 years, there is very little
chance of being able to get the exact same drive again, as they will be
replaced by new models.

So: how identical do they really have to be? Will it suffice to get
another 7200 RPM drive of the same form factor (3.5") with same capacity
(let's say 500 Gb) and same interface (say: SATA), but a different
model, or even vendor? If no, what physically prevents the RAID from
accepting other models?

Thanks! - Jurgen

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The drives don't have to be identical. The only requirements are the new drive must work on the same interface and be at least as large as the old one.

JML wrote:

I am shopping for a good RAID 5 solution for network storage. I have
several candidates in mind, most of which are traditional RAID5
solutions (Drobo is not, different story).

How identical do hard drives need to be for a RAID when replacing one at
a time? If I buy 4 Seagate, 500Gb, 7200 rpm drives now, they have a
5-year warranty. When one of them dies in 5 years, there is very little
chance of being able to get the exact same drive again, as they will be
replaced by new models.

So: how identical do they really have to be? Will it suffice to get
another 7200 RPM drive of the same form factor (3.5") with same capacity
(let's say 500 Gb) and same interface (say: SATA), but a different
model, or even vendor? If no, what physically prevents the RAID from
accepting other models?

Thanks! - Jurgen

When replying to email, remove _no_spammos_