I am using centos 7 and I have a /home mounted on an xfs filesystem on a dedicated LVM partition./dev/mapper/centos-home        782G   34M  782G   1% /homeI want to split this partition to 2 partitions, one of them to be mounted on /home, is there any way I can do this while the OS is running normaly, like I don't have to boot into livecd.
Split home partition into 2 (xfs on LVM)
lvm;size;xfs
The usual approach to splitting a filesystem would be to shrink the existing filesystem and create a new one in the space which is made free.However, you cannot shrink an xfs filesystem.  According to the FAQ Is there a way to make a XFS filesystem larger or smaller?:You can NOT make a XFS partition smaller online. The only way to shrink is to do a complete dump, mkfs and restore.An XFS filesystem may be enlarged by using xfs_growfs(8).If using partitions, you need to have free space after this partition to do so. Remove partition, recreate it larger with the exact same starting point. Run xfs_growfs to make the partition larger. Note - editing partition tables is a dangerous pastime, so back up your filesystem before doing so.Using XFS filesystems on top of a volume manager makes this a lot easier. The size of your current /home is small (as filesystems go, nowadays), so the approach would be tobackup your /home (on some other filesystem or computer)delete the xfs filesystemcreate the new filesystems to your tasterestore the backupFurther reading:XFS FAQ