[CentOS] LVM

[John R Pierce]

On 03/18/12 10:34 AM, madunix at gmail.com wrote:
> I need to shrink /home(755G) to 150GB and use free space to add to the
> existing /(50G).
> #df -kh
> Filesystem           Size  Used Avail Use% Mounted on
> /dev/mapper/vg_web-lv_root 50G  7.8G   40G  17% /
> tmpfs                 7.8G  384K  7.8G   1% /dev/shm
> /dev/sda2             485M   79M  381M  18% /boot
> /dev/sda1             200M  256K  200M   1% /boot/efi
> /dev/mapper/vg_web-lv_home755G  6.2G  711G   1% /home
>
> Need to have the step, can this be done online or need to go offline
> (umount) the file systems.

IMHO, the only sane way to shrink a file system is to back it up to 
other media, delete it, then recreate it at the new smaller size and 
restore the backup.

my /'s are rarely bigger than 18GB, but I usually mount other file 
systems for stuff like /var/www, /var/pgsql-x.y/data, etc.

-- 
john r pierce                            N 37, W 122
santa cruz ca                         mid-left coast