Ripro Backup (Legato)
Jukebox error, Illegal Request, ASC 0x3b ASCQ 0x83

L. Weissmann
09/15/98

Title:

Set load_sleep to delay accessing the device

Jukebox hangs during mount request.

One of the following errors may also be returned during the mount request:

• tape:  verify label operation in progress
• media warning:  tape <device name> opening io error
• open error

Analysis:

NetWorker is trying to open the device before the device is completely ready.

On a UNIX system the message "verify label operation in progress" is returned by the nsrmmd program.

Once a volume is loaded into the drive the nsrjb program makes a request to have the volume mounted.  The mount request is sent to the nsrd program.  Nsrd allocates an nsrmmd to perform the mount and label operation.

The nsrmmd attempts to position the volume to read the label. If the attempt fails, the message "verifying label operation in progress" is returned. The reason for this failure is because the device is not available when nsrmmd is attempting to access the device to read the label and mount the volume.

If the device is available, NetWorker will mount the volume.

Different errors may be returned depending upon the state of the device when the nsrmmd is attempting to access the device to read the label and mount the volume.  Several of the errors are listed above.

To be more specific, the NetWorker design does not check the drive's status before trying to access or open the drive.

Note:

Only device driver level applications can poll the device and wait until the device is ready.

Occasionally, NetWorker may prematurely access a drive before the drive is ready and cause a system to hang. The reason for this behavior is because that the nsrmmd is an application process and requires the device to be open before any reads or mounts can be issued.

SOLUTION:

Set the load_sleep parameter to a value in seconds.

For example, "load_sleep=300" will cause nsrjb to wait for 300 seconds before attempting the access the device.  The default value is 15 seconds.  If this option is not set (!load_sleep), then the default value is 0 seconds.

This delay was added to NetWorker for devices which return asynchronously from the load operation before the device is ready.

Use the NetWorker Administration GUI (nwadmin) to set this parameter.

On UNIX:

1. Select Media => Jukeboxes => View => Details => Jukebox options
2. Type "load_sleep=n" where n is the number of seconds

On Windows NT:

1. Select Options => Customize => Check "Display Hidden Attributes"
2. Select Autochanger => Left click on specific autochanger and select Edit
3. Select Preference tab => Jukebox options
4. Type "load_sleep=n" where n is the number of seconds.