raids

[Luke Davis]

Greg is correct on all counts.

You have to create the MD devices from the "setup software RAID" option, 
prior to formatting anything.

After you do this, you will have to create your new file systems (EXT3, 
etc.) on those MD devices, not on HDA or HDB.

You are building layers.

It seems as if you have tried to put layer 2 on top of layer 0, instead of 
layer 1 (RAID) on top of 0 (the raw partitions), and then 2 (the file 
systems) on top of 1 (RAID).

Additionally, since you are trying to mount both file systems on slash, 
you may not realize that unix sees everything as one single file system.  
You have one, mounted at slash (the root FS), and others mounted at 
various mount points thereunder.

You should not think of software RAID as a file system which must be 
mounted, but as a partitioning layer gwhich must be created before you can 
mount anything.

For example, if you have HDA1 and HDB3, of identical sizes, and you wanted 
to operate a RAID 1 device using those partitions, you would create a 
device called MD0, by using the RAID setup tools appropriate (or the 
installer if it supports it, which yours' seems to do).  Then, instead 
of having HDA1 or HDB3 any more, you will have only MD0.  You will make 
one file system, on MD0, and leave the HDA1 and HDB3 devices alone, as 
RAID's md0 is now handling them.

Regards,

Luke


On Sat, 9 Sep 2006, Gregory Nowak wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> You need to make the mount point be something other then / for 1 of the
> drives, you can't put 2 partitions on the same mount point, like that
> message box says.
> 
> Also, from the subject of your message, and based on what you told us
> in your first post, you're setting up a raid. I don't know if it's
> software or hardware, and I also haven't used software raid since the
> 2.4.x kernels. So, I stand to be corrected, but if you're setting up
> software raid under gnu/linux, partitioning the drives individually,
> with separate file systems,  is
> not the way to do it, unless things have drastically change since I
> did it, which I doubt is the case. You should be able to find the
> software raid howto on tldp.org, and I suggest that you read that, if
> you're in fact setting up software raid.
> 
> Greg
> 
> 
> On Fri, Sep 08, 2006 at 10:57:14PM -0700, Ned Granic wrote:
> > Thanks folks for the help with hardware.
> > 
> > Then, I came to a halt again!
> > Manually partitioning the disks:
> > After matching the partitions from hda (master) and hdb (slave), and 
> > clicking on "finish and write changes to disk", the following error pops up:
> > 
> > <box>
> > partition disks:
> > identical mount points for two file systems.
> > Two file systems are assigned the same mount point (/):
> > ide1 master, partition #1 (hda1) and ide slave, partition #1 (hdb1).
> > please correct this by changing mount points.
> > <end box>
> > So on both drives there is the root partition with the ext3 fs, they are 
> > both set to be formatted, the bootable flag is set on both, the mount points 
> > are / (root dir), and sizes are identical.
> > Finally, they are matched.
> > 
> > How to proceed?
> > 
> > Many thanks in advance!
> > Ned
> > 
> 
> - -- 
> web site: http://www.romuald.net.eu.org
> gpg public key: http://www.romuald.net.eu.org/pubkey.asc
> skype: gregn1
> (authorization required, add me to your contacts list first)
> 
> - --
> Free domains: http://www.eu.org/ or mail dns-manager at EU.org
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.5 (GNU/Linux)
> 
> iD8DBQFFAmeo7s9z/XlyUyARAm+6AKCKBagujzZ0aX5CGUTpCnYtgbmVhgCgvmxB
> v+pcmp65HEvxcBDSodnf/NI=
> =I8I1
> -----END PGP SIGNATURE-----
> 
> _______________________________________________
> Speakup mailing list
> Speakup at braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>