HP StorageWorks X3000 Network Storage Systems - Manual (Page 59)

Scheduling defragmentation
Defragmentation is the process of analyzing local volumes and consolidating fragmented files and
folders so that each occupies a single, contiguous space on the volume. This improves file system
performance. Because defragmentation consolidates files and folders, it also consolidates the free
space on a volume. This reduces the likelihood that new files will be fragmented.
Defragmentation for a volume can be scheduled to occur automatically at convenient times.
Defragmentation can also be done once, or on a recurring basis.
NOTE:
Scheduling defragmentation to run no later than a specific time prevents the defragmentation process
from running later than that time. If the defragmentation process is running when the time is reached,
the process is stopped. This setting is useful to ensure that the defragmentation process ends before
the demand for server access is likely to increase.
If defragmenting volumes on which shadow copies are enabled, use a cluster (or allocation unit) size
of 16 KB or larger during the format. Otherwise defragmentation registers as a change by the Shadow
Copy process. This increase in the number of changes forces Shadow Copy to delete snapshots as
the limit for the cache file is reached.
CAUTION:
Allocation unit size cannot be altered without reformatting the drive. Data on a reformatted drive
cannot be recovered.
For more information about disk defragmentation, read the online help.
Disk quotas
Disk quotas track and control disk space use in volumes.
NOTE:
To limit the size of a folder or share, see “ Quota management ” on page 84 .
Configure the volumes on the server to perform the following tasks:
• Prevent further disk space use and log an event when a user exceeds a specified disk space limit.
• Log an event when a user exceeds a specified disk space warning level.
When enabling disk quotas, it is possible to set both the disk quota limit and the disk quota warning
level. The disk quota limit specifies the amount of disk space a user is allowed to use. The warning
level specifies the point at which a user is nearing his or her quota limit. For example, a user's disk
quota limit can be set to 50 megabytes (MB), and the disk quota warning level to 45 MB. In this case,
the user can store no more than 50 MB on the volume. If the user stores more than 45 MB on the
volume, the disk quota system logs a system event.
In addition, it is possible to specify that users can exceed their quota limit. Enabling quotas and not
limiting disk space use is useful to still allow users access to a volume, but track disk space use on a
X1000 and X3000 Network Storage System 59