[linux-lvm] Setting up LVM with existing RAID 1 (Mirror)
Dieter Stüken
stueken at conterra.de
Tue Jun 27 09:04:22 UTC 2006
Hi Rehan,
If I have a look at your partition table
> Disk /dev/sda: 73.2 GB, 73274490880 bytes
> 255 heads, 63 sectors/track, 8908 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>
> Device Boot Start End Blocks Id System
> /dev/sda1 * 1 784 6297448+ 83 Linux
> /dev/sda2 785 8907 65247997+ f W95 Ext'd (LBA)
> /dev/sda5 785 1176 3148708+ 82 Linux swap
> /dev/sda6 1177 1960 6297448+ 83 Linux
> /dev/sda7 1961 2744 6297448+ 83 Linux
> /dev/sda8 2745 3528 6297448+ 83 Linux
> /dev/sda9 3529 3790 2104483+ 83 Linux
> /dev/sda10 3791 4052 2104483+ 83 Linux
it seems /dev/sda2 is a container holding sda5-10 as logical
partitions. This concept is similar to a LVM layout, where sda2
would be a physical volume (PV) containing several logical volumes
(LV) like /opt /home swap etc.
But even if you have a lot of free space within sda2, it does
not help you, as long as the whole disk is occupied by sda2.
You have to get rid of all the logical partitions :-(
But you may keep your root partition :-)
step 1: erase sda5-10
You may copy /usr /var and /home into your root partition
(use: cp -a). Swap can be disabled for a while. But you
have to save /opt (may be /tmp) to an additional disk.
Then you are able delete sda5-10.
step 2: initialize LVM / create a logical volume
Turn sda2 into a PV with "pvcreate /dev/sda2".
Create a logical volume: "vgcreate volume1 /dev/sda2".
You may choose any other name instead of "volume1".
Now you create your LVs as needed:
lvcreate volume1 -n swap -l 2G
lvcreate volume1 -n usr -l 6G
lvcreate volume1 -n opt -l 12G
....
mkswap /dev/volume1/swap
mke2fs /dev/volume1/usr
mke2fs /dev/volume1/opt
...
step 3: copy back the data to your newly created LVs.
conclusion:
Your new LVs have real names instead of just /dev/sda8.
Any free space you have may be assigned to any of your
LVs, as they don't have to be continuous any more.
Anyway, dealing with additional disk space is MUCH
easier once after you started using LVM.
Dieter.
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