Adding a disk and extending my file System

[ousseynou diagne]

I have disk cabinet with 7 physical volumes configured as Vg02 with 5 logical volumes

- /dev/dsk/c0t8d0 < ---- > /dev/dsk/c1t8d0, mirrored Free PE = 0
(/db01mounted on /dev/vg02/lvol1)

- /dev/dsk/c0t9d0 < ------- > /dev/dsk/c1t9d0 mirrored, Free PE = 0
(/db03 mounted on /dev/vg02/lvol1)

- /dev/dsk/c0t10d0, Free PE = 0 < ------ > Empty bay
(c0t10d0 hold db03 mounted on /dev/vg02/lvol3, /testdb, mounted on dev/vg02/lvol5)

- /dev/dsk/c0t11d0 Free PE = 0 < ------ > /dev/dsk/c1t11d0 Free PE = 670
(c0t11d0 hold /db03 mounted on /dev/vg02/lvol3, /avdb on /dev/vg02/lvol4 and /testdb on /dev/vg02/lvol5, lvol4 is mirrored too )

How to extended lvol1 and lvol2 to provide more disk space to db01 and db02, lvol1 and lvol2 are mirrored.


My db01 on lvol1 and db02 on lvol2 are almost full I want to extended lvol1 and lvol02. Right now the only free extends available are on c1t11d0. I want to add a disk on the empty bay as c1t10d0 but there is no free space available on c0t10d0 to mirror to. Mirrored space is required to extend lvol1 and lvol2. However /testdb mounted on lvol5, which is spread out on the 3 disks c0t10d0, c0t11d0 and c1t11d0 is just a test database I can delete and recreate later where free space will be available.

I guess I can safely delete /dev/vg02/lvol5, my test database and use the space to extended lvol1 and lvol2 on mirrored c0t10d0 and c1t10d0 (new disk added). I am using HFS on HP 10.20. How should I proceed and what are the commands. Do I have to boot under user mode in order to delete lvol5 and extend the file system.


Thank you

[S.K. Chan]

It's hard to tell accurately how the extents are spread out without the "pvdisplay" output of each disks. What I'll do is first delete the 15GB lvol5 then re-evaluate how the layout would look like afterwards. To make this clean I think you would have to "pvmove" lvol3 (which is not mirrored) because now it's spread out onto 3 disks. Well why don't you do that first (delete lvol5 )..
# umount /testdb
# lvremove /dev/vg02/lvol5
# vi /etc/fstab
==> Comment out "/testdb" entry.
Then re-post all your LVM config again, this time also provide "pvdisplay -v" output of all the last 3 disks (c0t10d0, c0t11d0 and c1t11d0). That would help determine what's the best way to do this.

[Sridhar Bhaskarla]

Hi,

If I understood correctly, I would do the following.

1. Add a new disk (say c1t10d0) of the same size as of c0t10d0 to the empty bay.

ioscan -f
ioscan -fnC disk (identify the device file)
insf
pvcreate /dev/rdsk/c1t10d0
vgextend vg02 /dev/dsk/c1t10d0

2. Remove lvol5. This will free up c0t10d0, c0t11d0 and c1t11d0 (if it has part of lvol5). You have c1t10d0 free anyway.

lvremove /dev/vg02/lvol5

3. Mirror lvol3 onto c1t10d0 (new disk). This is completely optional. But your setup will be consistent to have all the db* volumes mirrored. This will leave equal amount of space on c1t10d0 and c0t10d0.

lvextend -m 1 /dev/vg02/lvol3 /dev/dsk/c1t10d0

4. Now extend lvol1 onto c0t10d0 and c1t10d0 (new disk)
lvextend -L new_size_in_mb /dev/vg02/lvol1 /dev/dsk/c0t10d0 /dev/dsk/c1t10d0

5. Extend lvol2 onto c0t11d0 and c1t11d0

lvextend -L new_size_in_mb /dev/vg02/lvol2 /dev/dsk/c0t11d0 /dev/dsk/c1t11d0

Please remember the size you can use is the minimum of the available spaces in the disk pair.

For ex., if c0t10d0 has 100MB and c1t10d0 has 200 MB, you can only use 100MB.

-Sri