Volume uses less space after "vol copy", why?


I've recently moved a volume (and all snapshots) from one aggregate to another using "vol copy -S". Everything went smoothly. (The volume is used as a SnapVault target).

However, when i do a "df -V -h" I notice that the new volume shows a capacity of 35% but the old shows 53% !?! The "used" for the volumes, as well as for their snapshots, are identical. But the "avail" is different, and hence the "capacity" as well.

Filesystem                                        total          used          avail         capacity     Mounted on
/vol/sv_eBackup04_old/                    4096GB     1427GB     1929GB      53%            /vol/sv_eBackup04_old/
/vol/sv_eBackup04_old/.snapshot           0GB       309GB          0GB       ---%           /vol/sv_eBackup04_old/.snapshot
/vol/sv_eBackup04/                          4096GB     1427GB     2668GB      35%           /vol/sv_eBackup04/
/vol/sv_eBackup04/.snapshot                 0GB       309GB          0GB      ---%           /vol/sv_eBackup04/.snapshot

Why is this so? What are the extra space used for in the original volume? And is their a way to "reclaim" this space in other volumes as well without doing a vol copy? Or am I missing something obvious?

Any hints appreciated.


/Ulrik Ivers

Re: Volume uses less space after "vol copy", why?

Please check the fractional reserve on the source and the destination volumes.

The fractional reserve on the source volume would be higher and hence it shows more space as consumed with the same amount of actual data