madunix at gmail.com
madunix at gmail.com
Tue Mar 20 07:13:28 EDT 2012
Attention: Shrink/Extend a filesystem may damage the data on it, pls backup
1. Decrease /dev/mapper/vg_web-lv_home
# umount /dev/mapper/vg_web-lv_home
# e2fsck -f /dev/mapper/vg_web-lv_home
# resize2fs /dev/mapper/vg_web-lv_home <size>
# lvresize -L <size> /dev/mapper/vg0-lv_home
# mount -o remount /home
check the size of /dev/mapper/vg_web-lv_home with "df -kh"
2. Increase /dev/mapper/vg_web-lv_root
# lvresize -L <size> /vg_web-lv_root
# resize2fs /vg_web-lv_root
check the size of /dev/mapper/vg_web-lv_root with "df -kh"
Filesystem Size Used Avail Use% Mounted on
296G 7.1G 274G 3% /
tmpfs 7.8G 176K 7.8G 1% /dev/shm
/dev/sda2 485M 84M 377M 19% /boot
/dev/sda1 200M 256K 200M 1% /boot/efi
99G 6.3G 88G 7% /home
On Tue, Mar 20, 2012 at 12:04 PM, Markus Falb <markus.falb at fasel.at> wrote:
> On 19.3.2012 10:16, John R Pierce wrote:
> > On 03/19/12 2:14 AM, Peter Kjellström wrote:
> >> I can also add that I've successfully managed to shrink ext3 before
> >> verified backup is probably good advice..
> > does resize2fs relocate blocks or is it restricted to shrinking only to
> > last high water block in use ?
> I found this in resize/resize2fs.c.unused_group_blocks
> * Resizing a filesystem consists of the following phases:
> * 1. Adjust superblock and write out new parts of the inode
> * table
> * 2. Determine blocks which need to be relocated, and copy the
> * contents of blocks from their old locations to the new ones.
> * 3. Scan the inode table, doing the following:
> * a. If blocks have been moved, update the block
> * pointers in the inodes and indirect blocks to
> * point at the new block locations.
> * b. If parts of the inode table need to be evacuated,
> * copy inodes from their old locations to their
> * new ones.
> * c. If (b) needs to be done, note which blocks contain
> * directory information, since we will need to
> * update the directory information.
> * 4. Update the directory blocks with the new inode locations.
> * 5. Move the inode tables, if necessary.
> Kind Regards, Markus Falb
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