When space reservation is enabled for one or more files, Data ONTAP reserves enough space in the volume (traditional or FlexVol) so that writes to those files do not fail because of a lack of disk space. Other operations, such as snapshots or the creation of new files, can occur only if there is enough available unreserved space; these operations are restricted from using reserved space.
Writes to new or existing unreserved space in the volume fail when the total amount of available space in the volume is less than the amount set aside by the current file reserve values. Once available space in a volume goes below this value, only writes to files with reserved space are guaranteed to succeed.
File space reservation is an attribute of the file; it is persistent across storage system reboots, takeovers, and givebacks.
There is no way to automatically enable space reservations for every file in a given volume, as you could with versions of Data ONTAP earlier than 7.0 using the create_reserved option. In Data ONTAP 7.0, to guarantee that writes to a specific file will always succeed, you need to enable space reservations for that file. (LUNs have space reservations enabled by default.)
Note
For more information about using space reservation for files, see your Block Access Management Guide, keeping in mind that Data ONTAP manages files exactly the same as LUNs, except that space reservations are enabled automatically for LUNs, whereas for files, you must explicitly enable space reservations.
To enable space reservation for a file, complete the following step.
| 1 |
file reservation file_name [enable|disable] file_name is the file in which file space reservation is set. enable turns space reservation on for the file file_name. disable turns space reservation off for the file file_name. Example:file reservation myfile enable Note |
Turning on space reservation for a file fails if there is not enough available space for the new reservation.
To find out the status of space reservation for files in a volume, complete the following step.
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Part No. 210-01085_B0
File: 6vol29.htm
Last updated: 01-Dec-2005 16:51:37