A. Run defragfs -r /data1; defragfs /data1
B. Run defragfs -r /dev/lv01; defragfs /dev/lv01
C. Back up the filesystem by name, unmount the filesystem, recreate the filesystem by running mkfs /dev/lv01, and restoring the data from the backup.
D. Back up the filesystem by inode, unmount the filesystem, recreate the filesystem by running mkfs /dev/lv01, and restoring the data from the backup.