About downed drives
NetBackup downs a drive automatically when there are read or write errors that surpass the threshold within the time window. The default drive error threshold is 2. That is, NetBackup downs a drive on the third drive error in the default time window (12 hours).
Common reasons for write failures are dirty write heads or old media. The reason for the action is logged in the NetBackup error catalog (view the Media Logs report or the All Log Entries report). If NetBackup downs a device, it is logged in the system log.
You can use the NetBackup nbemmcmd command with the -drive_error_threshold and -time_window options to change the default values.
For more information about nbemmcmd, see the NetBackup Commands Reference Guide.
To reverse a down action, in the NetBackup Administration Console, expand Media and Device Management > Device Monitor to set the device to Up.
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