Reducing LVM xfs format filesystem


In this post we are going to see Reducing LVM xfs format filesystem.

Reducing LV size on xfs fileystem is little different from reducing LV size on etx4/3/2 fileystem’s.

Follow the below steps to perform this:

1. As first step take data backup using xfsdump

2. Then unmount the fileysystem

3. Now shrink the logical volume to the required size using lvreduce command.

4. Format the filesystem using xfs format.

Note: While we reducing size over etx4/3/2 filesystems, will use resize2fs command to shrink instead of formating. So, we no need to take data backup while using etx4/3/2 filesystem for LVM.

5. Mount the filesystem again.

6. Now finally restore the data using xfsrestore command.

LVM details are below:

VG Name: newvg

LV’s: lv1, lv2. Going to use lv2 for this lab.

Use lvs command to check the size of existing LV’s

[root@localhost ~]# lvs
 LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
 lv1 newvg -wi-ao---- 6.00g
 lv2 newvg -wi-a----- 7.00g

lv2 has been mounted under /lvolume2 mount point. Now take the backup of /lvolume2 under /tmp filesystem like below.

[root@localhost ~]#xfsdump -f /tmp/lv2.dump /lvolume2

Now unmount the filesystem using below command:

[root@localhost ~]# umount /lvolume2

Reduce or shrink the size to required size using lvreduce command:

In below example we are going to reduce the lv2 filesystem size from 7Gb to 6GB.

[root@localhost ~]# lvreduce -L -1G /dev/newvg/lv2
 WARNING: Reducing active logical volume to 6.00 GiB.
 THIS MAY DESTROY YOUR DATA (filesystem etc.)
 Do you really want to reduce newvg/lv2? [y/n]: y
 Size of logical volume newvg/lv2 changed from 7.00 GiB (1792 extents) to 6.00 GiB (1536 extents).
 Logical volume newvg/lv2 successfully resized.

Now format the filesystem using below command:

[root@localhost ~]#mkfs.xfs -f /dev/newvg/lv2

Mount the filesystem again into the /lvolume2

[root@localhost ~]#mount /dev/newvg/lv2 /lvolume2

Finally restore the backup data

[root@localhost ~]#xfsrestore -f /tmp/lv2.dump /lvolume2


Reference: yallalabs

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