On 4/30/06, T. Bryan <[EMAIL PROTECTED]> wrote:
On Sunday 30 April 2006 04:12 pm, Rick DeNatale wrote:

> Well here's some more information on my setup.  I've got my root fs
> and a swap "volume" as logical volumes on a raid1 array
>
> $ cat /proc/mdstat
> Personalities : [raid1]
> md0 : active raid1 sda5[0] sdb5[1]
>       8634816 blocks [2/2] [UU]
>
> unused devices: <none>
>
> $ sudo lvmdiskscan -v
>   /dev/md0  [        8.23 GB] LVM physical volume

Thanks for the comparison.  That's pretty much what I expected to see.  I just
wish that I had run and captured the output from these commands when it
looked like things were working.

> I'm a little suspicious about those lines in your output:
> >   /dev/hde1 [      111.79 GB] LVM physical volume
> >   Found duplicate PV 7LOs90S2Ff8W7Tq8ZGRsT41lphbExsLh: using /dev/hdg1
> > not /dev/hde1
> >   /dev/hdg1 [      111.79 GB] LVM physical volume

Me, too.  :)

> To me this looks like, instead of building a raid array with two
> physical partitions and then making that a PV, you tried to make a
> raid array from two LVM PVs.

That's not what I attempted.  My journal says that I set this up with

mke2fs -j /dev/hde1
mke2fs -j /dev/hdg1
mdadm --create --verbose /dev/md0 --level=1 \
      --raid-devices=2 /dev/hde1 /dev/hdg1
mdadm -S /dev/md0
mdadm -As /dev/md0

pvcreate /dev/md0
vgcreate localvg /dev/md0
lvcreate -L20G -nlv_local1 localvg
mke2fs -j /dev/localvg/lv_local1

I wasn't sure whether I needed to mke2fs both on the underlying device and on
the logical volumes, but it seemed to work well for a while, and I was
reading and writing data to the logical volume.  It would be nice to get it
working again.  :)

Here are the steps I took to move my root to an LVM on top of raid. I've copied this from the ticket I created for the job in request
tracker, and have edited it slightly. I was quite cautious with this
plan since I was migrating the root filesystem, which I don't think
you are doing.

1) Partition /dev/sdb like /dev/sda

2) Create the raid array with a missing drive
$mdadm --create /dev/md0 --level 1 --raid-devices=2 missing /dev/sdb5

3) Create a PV on the raid array
$pvcreate /dev/md0

4) create a VG
$vgcreate MainVG /dev/md0

5) Create the LVs
$lvcreate -l 2013 MainVG -n root
$lvcreate -l 95 MainVG -n swap_1

6) Format the LVs
$mkfs.ext3 /dev/MainVG/root
$mkswap /dev/MainVG/swap_1

7) Mount the new root LV
$sudo mkdir /mnt/root
$sudo mount /dev/MainVG/root /mnt/root


8) Copy the root partition
$cp -dpRx / /mnt/root

9) Mount the boot partition and copy it.  This shouldn't be necessary
in your case.

10) Install grub on the new drive  Neither should this

11) Edit /mnt/root/etc/fstab to use the md device.  Of course your
/etc/fstab would
be different.

/dev/sdb1 /boot ext3 defaults 0 2
/dev/mapper/MainVG-root / ext3 defaults,errors=remount-ro
0 1
/dev/mapper/MainVG-swap_1 none swap sw 0 0

12) edit /mnt/boot/grub/menu.lst to change Ubuntu to MainVG  This
shouldn't apply to you since you aren't changing the root filesystem
to raid/LVM.

13) Planned hold <G> (To avoid an actual step 13)

14) touch /mnt/root/home/rick/newvg so that we can see that we actually
get the new setup.  Again, not applicable in your case, I wanted to
make sure that I'd actually gotten the right root filesystem after the
reboot.

15) Cross fingers and reboot

16) Look for /home/rick/newvg  see #14

17) Test the new config to make sure it's the same system!

18) Now add /dev/sda5 to the raid
$sudo mdadm --add /dev/md0 /dev/sda5

This wipes the contents of /dev/sda5 and syncs it with /dev/sdb

19) $watch cat /proc/mdstat
looking for sync to complete status will be [UU]



> My setup has LVM on top of raid.  I know that way works, I'm not sure
> whether or not raid on top of LVM does.

Another question.  What is your partition type for /dev/sda5 and /dev/sdb5?

$sudo fdisk -l /dev/sda /dev/sdb
...
/dev/sda5              32        1106     8634906   8e  Linux LVM

Disk /dev/sdb: 9173 MB, 9173114880 bytes
...
/dev/sdb5              32        1106     8634906   fd  Linux raid autodetect


None of the HOWTOs mentioned changing it, but I notice that partition type 8e
is Linux LVM, but mine is 83 (Linux) for ext3.

I didn't do anything to explicitly change the partition type with
fdisk/sfdisk.  I beleive that they got that way as a side-effect of
the mdadm and pvcreate commands.  Given your symptoms I suspect that
the problem isn't the 83 vs 8e, but the 83 vs fd partition types.

--
Rick DeNatale

Visit the Project Mercury Wiki Site
http://www.mercuryspacecraft.com/
--
TriLUG mailing list        : http://www.trilug.org/mailman/listinfo/trilug
TriLUG Organizational FAQ  : http://trilug.org/faq/
TriLUG Member Services FAQ : http://members.trilug.org/services_faq/

Reply via email to