Setting space reservation values for qtrees

What space reservation values for qtrees are

When space reservation values are set for a qtree, all subsequent files created in that qtree are created with the type of space reservation specified. Reservations can be controlled individually to reserve space for overwrites of existing file data or to reserve space to fill holes in the file (areas in the file that have never been written to). Turning these settings on or off does not change the reservation setting for any existing files in the qtree.

These values can be set for volumes as well as for qtrees. If these values are set to On for the volume, they will affect new files created in qtrees in the volume, no matter what the space reservation settings for the qtrees are, as well as new files created outside of qtrees in the volume.

If these values are set to Off for a volume, setting the values to On for a qtree in that volume means that all new files created in that qtree will have the values turned on.

Enabling space reservations for qtrees

To enable space reservations for files in a specified qtree, complete the following step.

Step	Action
1	Enter the following command: *qtree reservation qtree_name* [overwrite\|fill] [enable\|disable]** qtree_name is the qtree in which file reservations are set. `enable` turns space reservations on for new files created in qtree_name. `disable` turns space reservations off for new files created in qtree_name. `fill` enables space reservations only to fill holes in new files created in qtree_name. `overwrite` enables space reservations only to overwrite blocks that have already been written in new files created in qtree_name. Specifying `qtree reservation enable` or `disable` without specifying `fill` or `overwrite` turns both options on or off. Examples qtree reservation qtree5 enable qtree reservation qtree5 enable overwrite qtree reservation qtree5 disable fill

Step

Action

Enter the following command:

qtree reservation qtree_name [overwrite|fill] 
[enable|disable]

qtree_name is the qtree in which file reservations are set.

enable turns space reservations on for new files created in qtree_name.

disable turns space reservations off for new files created in qtree_name.

fill enables space reservations only to fill holes in new files created in qtree_name.

overwrite enables space reservations only to overwrite blocks that have already been written in new files created in qtree_name.

Specifying qtree reservation enable or disable without specifying fill or overwrite turns both options on or off.

Examples



qtree reservation qtree5 enable

qtree reservation qtree5 enable overwrite

qtree reservation qtree5 disable fill

Querying space reservations for qtrees

To find out the status of space reservations for files on a qtree, complete the following step.

Step	Action
1	Enter the following command: *qtree reservation qtree_name* overwrite or qtree reservation qtree_name fill** qtree_name is the volume in which file reservations are set. Example qtree reservation qtree5 overwrite Note Even if qtree overwrite reservations are turned off, new files in the qtree will have overwrite reservations set if the volume option `reserve_overwrite` is turned on.

Step

Action

Enter the following command:

qtree reservation qtree_name overwrite

qtree reservation qtree_name fill

qtree_name is the volume in which file reservations are set.

Example

qtree reservation qtree5 overwrite

Note
Even if qtree overwrite reservations are turned off, new files in the qtree will have overwrite reservations set if the volume option reserve_overwrite is turned on.