User's Manual

106 Managing media
Example output of the fsemedium --list --volume command
Changing the condition status of media
The Resource Management Database recognizes three kinds of statuses which address a medium
condition: good, unreliable, and unusable. Typically, the latter two are used whenever FSE detects errors
on a medium. Such a medium is then automatically marked appropriately as either unreliable or unusable.
The FSE implementation provides an option to use the medium status for preventing further use of specified
media without having to put them off-site, and then to change their status back to be fully available.
Depending on the operation you want to prevent being performed on a medium, you can mark it as either
unreliable or unusable. To change a medium condition, you need to know its barcode.
Status “good” refers to the good condition of a medium. It needs to be set manually by the administrator if
the medium was previously defective but has been repaired and is ready to be put back to use. If you have
manually marked the medium as unreliable or unusable, and you want to make it “good” again, you also
need to mark it as such.
Preventing writing to an FSE medium
If you want to prevent further writing to a medium, but still need to access data on the medium in case no
other medium copy is available, set its status to unreliable:
Once the medium is marked as unreliable, the medium can only be used for reading data.
Preventing reading from and writing to an FSE medium
If you want to prevent further use of a medium, set its status to unusable:
Putting an FSE medium back into use
If there were errors detected on a medium, but now the medium is fixed and you want to put it back to use,
you can set its condition to good:
Once the medium is marked as good, data on the medium can be read and the medium can be written to.
Closing medium volumes
By closing a medium volume you mark it as full and set its status in the Resource Management Database
accordingly; therefore further writing to it is no longer possible. This operation also saves Fast Recovery
Information to the end part of the medium volume and to the medium system volume, if it is present. If
writing Fast Recovery Information to a medium fails, an appropriate warning is displayed.
For example, if you want to duplicate a medium which is almost full, you can close the original medium
volumes in order to prevent further writing to it. For more details, see ”Duplicating media” on page 92.
Closing a medium volume is also useful in situations where the status of a whole FSE medium is set to
unreliable due to a problem with a particular medium volume. Such problematic volume disables further
use of other error-free medium volumes. When you close the unreliable medium volume and set the
medium status to “good” (as described in ”Putting an FSE medium back into use” on page 106) you
enable further use of other medium volumes on the same medium.
fsemedium --list 000045 --volume
Barcode VolNum Type Size[MB] Avail[MB] Used[%] Status
000045 1 System 1138 1126 1 open
000045 2 Data 1138 0 95 full
000045 3 Data 48172 42391 12 open
fsemedium --mark-unreliable Barcode
fsemedium --mark-unusable Barcode
fsemedium --mark-good Barcode