----- Original Message -----
> From: "Les Mikesell" <lesmikesell@xxxxxxxxx>
> To: "CentOS mailing list" <centos@xxxxxxxxxx>
> Sent: Thursday, September 29, 2011 2:16:16 PM
> Subject: Re: add on sata card relabeling drives, installation
>
> On Thu, Sep 29, 2011 at 4:09 PM, David C. Miller
> <millerdc@xxxxxxxxxxxxxx> wrote:
> >
> > This type of issue is why relying on /dev/sdX is bad. Mounting
> > based on uuid or label when available is best. Unfortunately,
> > there are controller cards that present all disks as the same
> > uuid. It makes using mdadm that can only see /dev/sdX a pain to
> > use.
>
> So how do you propose getting a uuid or label on a disk in the first
> place if you can't identify which is which physically? And how do
> you
> know which to move when you want the content in some other box?
>
> --
> Les Mikesell
> lesmikesell@xxxxxxxxx
I just had to come up with a solution for this recently. Here is what I did.
I create a small 2 block partition on each disk and gave them labels that is the drives serial number when I format them as ext3/4. I dedicate the rest of the disk to Linux auto RAID. Something like this to create a label.
mkfs.ext3 -L $DRIVE_SN /dev/sd1
I then have a script that mounts the small partitions by label to a directory with the same name as the label.
mount LABEL=$DRIVE_SN /mnt/drive-check/$DRIVE_SN
So if you do a df it will show something like.
Filesystem Size Used Avail Use% Mounted on
/dev/md0 71G 3.9G 63G 6% /
tmpfs 12G 0 12G 0% /dev/shm
/dev/sdc1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03208723
/dev/sdd1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03287844
/dev/sde1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03247298
/dev/sdf1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03247844
/dev/sdg1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03674888
/dev/sdh1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03678644
/dev/sdi1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03674814
/dev/sdj1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03675850
/dev/sdk1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03675194
/dev/sdl1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03288196
/dev/sdm1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03672314
/dev/sdn1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03287843
/dev/sdo1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03674460
/dev/sdp1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03585344
/dev/sdq1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03508896
/dev/sdr1 16M 1.2M 14M 8% /mnt/drive-check/WD-WMAY03209984
Now if I'm using mdadm to make a software RAID and it is complaining /dev/sdf2 is missing. I can run my script to mount all the small partitions and the one that complains it can't mount is easily identified by the serial number. Sure I can just let the hardware RAID card handle everything but I don't trust them from past experiences seeing failed cards and corrupted arrays. With the disks seen by linux as raw block devices I can put these disks on any JBOD controller and mount my raid using mdadm. I'm not tied to a particular controller if it fails.
David.
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
