Table of ContentsView in Frames

Use of deleted active file disk space

When enough disk space is available for Snapshot copies in the Snapshot copy reserve, deleting files in the active file system frees disk space for new files, while the Snapshot copies that reference those files consume only the space in the Snapshot copy reserve.

If Data ONTAP created a Snapshot copy when the disks were full, deleting files from the active file system does not create any free space because everything in the active file system is also referenced by the newly created Snapshot copy. Data ONTAP has to delete the Snapshot copy before it can create any new files.

Example

The following example shows how disk space being freed by deleting files in the active file system ends up in the Snapshot copy:

If Data ONTAP creates a Snapshot copy when the active file system is full and there is still space remaining in the Snapshot reserve, the output from the df command—which displays statistics about the amount of disk space on a volume—is as follows:
Filesystem           kbytes   used    avail   capacity
/vol/vol0/           3000000  3000000  0       100%
/vol/vol0/.snapshot  1000000  500000   500000  50%

If you delete 100,000 KB (0.1 GB) of files, the disk space used by these files is no longer part of the active file system, so the space is reassigned to the Snapshot copies instead.

Data ONTAP reassigns 100,000 KB (0.1 GB) of space from the active file system to the Snapshot reserve. Because there was reserve space for Snapshot copies, deleting files from the active file system freed space for new files. If you enter the df command again, the output is as follows:
Filesystem  	     kbytes    used     avail    capacity
/vol/vol0/           3000000   2900000  100000   97%
/vol/vol0/.snapshot  1000000   600000   400000   60%