Cybernetics miSAN-V6, Руководство оператора

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51 Operating the Web Control Panel
Cybernetics UM-MV-86-B1-0801
policy will pause and remain in the running state but will not access the disk(s)
until the host I/O finishes.
Individual jobs can be configured to either use or ignore this setting’s policy. Jobs
that ignore the policy run immediately without concern for the impact on the host’s
available I/O bandwidth.
You can make a job use or ignore this setting’s policy at any time by first selecting
the “Jobs” tab, then right-clicking the job, and then from the pop-up menu, select-
ing the desired option from the I/O scheduling submenu.
Host I/O idle minutes
“Host I/O idle minutes” specifies the amount of time the HSTC will wait from when
the host I/O stops before restarting job I/O. This option does not apply when
Con-
current
is selected for “Host vs. job I/O policy”.
Overwrite non-committed
The “Overwrite non-committed” setting determines whether a virtual tape
becomes write-protected after a backup. Write-protecting a virtual tape after a
backup ensures it will remain unchanged until a successful tape cartridge backup
has been committed (successfully copied). This secures against unintentional or
unauthorized virtual tape modification before a tape cartridge copy has been
made, since a host can neither append to nor erase a write-protected virtual tape.
Regardless of host write-protect status, a virtual tape can always be erased via
the “Virtual tapes” tab on the Web Control Panel.
If Enabled , a virtual tape will remain unprotected after a backup, making it avail-
able for appending or overwriting by another backup. Enabling the overwrite fea-
ture ensures a virtual tape is available for writing, even if its contents have not
been committed to tape. This is useful in cases where tape cartridge duplicates
are not always written for each virtual tape backup.
If Disabled , a virtual tape will be write-protected until it is committed to a tape car-
tridge. To keep track of which virtual tapes are write-protected, use the Web Con-
trol Panel. The “Copies” column on the “Virtual tapes” tab shows the number of
successful copies made. A virtual tape backup is write-protected if it has not been
successfully copied to a tape cartridge (‘0’ copies). Disabling the overwrite feature
ensures a tape cartridge duplicate will be made before a virtual tape can be modi-
fied, such as before an append or erase. This is useful in cases where a tape car-
tridge duplicate is always written for each virtual tape backup.
Note
If the miSAN-V-Series is configured with a virtual or physical stacker,
this setting will be unavailable and set to Enabled by default. This is to
allow host software to manage virtual tape protection, which would
otherwise interfere with protection controlled by the miSAN-V-Series.
This setting will also be unavailable if the miSAN-V-Series is not
configured to use a physical tape drive.