Re: [exim] RAID level for mailstore

Tom Brown wrote:
> Hi
>
> I wonder what people think for a RAID level for their mail stores?
>
> I can only have RAID 1 or RAID 5 and i dont have many users ~500 so what
> do people think? This will be on a hardware RAID card but the RAID
> channel will not be dedicated to the mail store ie there will be another
> RAID disk sharing the channel.
>
> Just want to lay the spindles out 'correctly'
>
> thanks
>
>

We consider RAID1 a practical necessity. Not just for mailstore, but
servers in general - anything but a laptop, really.

- with current HDD sizes - very affordable 500 GB, 750 GB, even 1 TB
there is not as much need for RAID5 unless you have a truly massive
storage need.

- RAID1 (usually) reads faster, isn't all that much slower on writes,
given that they are usually buffered/background - even aged or 'lazy'
writes anyway.

It is also easy to implement with anything from top-end 'hardware'
controllers thru el-cheapo psuedo-RAID or even all-software - one or
more 'flavors' of such being supported by most OS.

- RAID5, OTOH, really should have a good 'hardware' controller, and it
is not easy to cost-justify the better ones vs the 'waste' of rather
cheap HDD needed for a RAID1 mirror.

In either case - don't neglect backups.

RAID cannot protect against fire, theft, malicious damage, controller or
driver foibles - or more commonly - a mere lapse in attention that
mirrors a new, blank HDD onto the one with good data instead of the
other way 'round...

:-(

Bill