On Thu, 29 Oct 2009, ML wrote:
> My question is about initial setup. The 4 x 1TB drives. How to set
> this up for I have some protection?
>
> RAID 0+1? (striped + mirrored) I would end up with 2TB useable space.
>
> RAID 5? so what one is a hot spare? 3TB useable space?
>
> What about striping the 4 1TB and mirroring that to a 4 x 1tb External
> drive enclosure?
Plan for drives going out but keeping the site operational. Also
remember that RAID isn't a backup.
RAID 5 is enticing because you get more usable space out of your
drives, but you have to be sure you'll only lose one drive at a time
and can get a replacement drive in there and sync'ed up before you
lose a 2nd one... If the drives were made by the same manufacturer
and were bought at about the same time you might easily lose 2 or
more, blowing up your array.
Go with RAID 1+0 (mirroring + striping) and you can potentially lose
up to 1/2 of your drives and keep running. That's assuming you lose
the correct 1/2... If you lose two drives in the same mirror you
still go down.
Combine the above with a good backup strategy. Backup software has
been discussed on this list quite recently so look back a few days
or weeks and you'll find some good links. Practice and document
doing restores so that you know how to do them quickly without error
when the pressure's on.
Some of the backup software names/links I gleaned from this list
recently:
www.mondorescue.org
www.nongnu.org/duplicity (de-dupe, S3)
www.nongnu.org/storebackup (de-dupe)
amanda
backuppc (sourceforge) (rpm in epel)
www.backula.org (de-dupe)
--
Curt Mills, WE7U hacker at fluke dot com
Senior Methods Engineer/SysAdmin
"Lotto: A tax on people who are bad at math." -- unknown
"Windows: Microsoft's tax on computer illiterates." -- WE7U
"The world DOES revolve around me: I picked the coordinate system!"
Please be advised that this email may contain confidential information.
If you are not the intended recipient, please do not read, copy or
re-transmit this email. If you have received this email in error,
please notify us by email by replying to the sender and by telephone
(call us collect at +1 202-828-0850) and delete this message and any
attachments. Thank you in advance for your cooperation and assistance.
In addition, Danaher and its subsidiaries disclaim that the content of
this email constitutes an offer to enter into, or the acceptance of,
any
contract or agreement or any amendment thereto; provided that the
foregoing disclaimer does not invalidate the binding effect of any
digital or other electronic reproduction of a manual signature that is
included in any attachment to this email.