setting up a RAID-1 array with a non-empty hdd?
in [Storage]
|
Prev: Any way to revive a dropped 1.5TB Seagate drive? MUST GET IT TO SPIN UP
Next: Hard drive evolution could hit Microsoft XP users
From: yawnmoth on 9 Mar 2010 02:11 I have a hard drive whose contents I'd like to back up. I was thinking about using RAID-1 mirroring to do this. The thing I'm considered about is... will my drive be wiped? My second drive I don't really care about - that drives purpose is to just serve as a backup. But my main drive... I do care about that and reformating would rather defeat the point.
From: Arno on 9 Mar 2010 12:44 yawnmoth <terra1024(a)yahoo.com> wrote: > I have a hard drive whose contents I'd like to back up. I was > thinking about using RAID-1 mirroring to do this. The thing I'm > considered about is... will my drive be wiped? Yes. > My second drive I > don't really care about - that drives purpose is to just serve as a > backup. But my main drive... I do care about that and reformating > would rather defeat the point. The way to do this with a decent RAID conttroller or software RAID is as follows: Set up a degraded RAID1 with the second driv. Partition it and create the filesystem. Then copy everything over from the first fdirve. And then add the frist drive to the degraded RAID1 array to get redundancy. Side note: If the data on the frist drive is important, then surely you have a backlup of it? Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno(a)wagner.name GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans
From: yawnmoth on 9 Mar 2010 17:47 On Mar 9, 11:44 am, Arno <m...(a)privacy.net> wrote: > yawnmoth <terra1...(a)yahoo.com> wrote: > > I have a hard drive whose contents I'd like to back up. I was > > thinking about using RAID-1 mirroring to do this. The thing I'm > > considered about is... will my drive be wiped? > > Yes. > > > My second drive I > > don't really care about - that drives purpose is to just serve as a > > backup. But my main drive... I do care about that and reformating > > would rather defeat the point. > > The way to do this with a decent RAID conttroller or software > RAID is as follows: Set up a degraded RAID1 with the second > driv. Partition it and create the filesystem. Then copy everything > over from the first fdirve. And then add the frist drive to > the degraded RAID1 array to get redundancy. Any idea as to what RAID controllers might provide that functionality? <http://www.rosewill.com/products/942/ productDetail.htm> looked like a good RAID controller but when I asked them here's the response I got: Dear Customer we can not advise you on this, your data is important there by we cant asusre you that your cofiguration will work in this case .we will advise create your raid separated from the drive data then add drive with data as a secondary . And I'm not even sure what that means. > Side note: If the data on the frist drive is important, then surely > you have a backlup of it? A backup is what I'm trying to create.
From: David Brown on 10 Mar 2010 03:13 On 09/03/2010 23:47, yawnmoth wrote: > On Mar 9, 11:44 am, Arno<m...(a)privacy.net> wrote: >> Side note: If the data on the frist drive is important, then surely >> you have a backlup of it? > > A backup is what I'm trying to create. RAID is not a backup solution. At best, you could perhaps manage to make a single low-level copy of your disk in this way, which is not normally the best way to do backups, or at least not if this is your /only/ backup (for most people, it's their data that's most important). If you want to make low-level copies of a disk, use some sort of partition imaging software. There are plenty of such tools available to suit all tastes - from "dd" to expensive automated hand-holding pretty gui tools.
From: Arno on 10 Mar 2010 07:50
Ed Light <nobody(a)nobody.there> wrote: > Arno, > Is a drive in a RAID1 array instantly usable as a normal drive with data > and booting OS outside it, all by itself, or does it have some special > format? The controller typically places a RAID superblock on it and, if the superblock is at the start, shifts the sector numbers. The position and structure of the RAID superblock are unfortunately not standardized. Anyways, you lose the old format, but apart from that it is a nordinary drive, i.e. yes. One exception: Some controllers (cheap Fake-RAID controllers) may refuse to build a degraded array. I have been doing thie procedure I described with Linux software RAID several times, typically on resizing partition bases RAID. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno(a)wagner.name GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |