Receiving status code 129 when performing a backup. The policy has been setup to use a Storage Unit Group with multiple Disk Storage Units (DSU) setup for disk staging.

Article:TECH87559  |  Created: 2009-01-29  |  Updated: 2010-01-05  |  Article URL http://www.symantec.com/docs/TECH87559
Article Type
Technical Solution

Product(s)

Environment

Issue



Receiving status code 129 when performing a backup. The policy has been setup to use a Storage Unit Group with multiple Disk Storage Units (DSU) setup for disk staging.

Solution



When creating a Storage Unit Group with multiple DSU in the group, the options Prioritized, Failover, Round Robin, and Media server load balancing will function different for Disk storage units verse Media server storage units.

The following define how the option will work when the storage unit is configured for the selected option.

Prioritized
NetBackup chooses the first storage unit in the list that is not busy, down, or out of media. Also, the storage unit must not have reached the maximum concurrent jobs setting. When one of the specified conditions occurs, the next storage unit in the list is examined until NetBackup finds an available storage unit. If one is not available or if one does not have enough available space, the job fails and is not queued. (Default.)

Failover
NetBackup chooses the first storage unit in the list that is not down, out of media, or full. If a storage unit is only busy, the policy waits to write to it. The other storage units are used as failover.

NetBackup queues a job to wait for the first storage unit if the maximum concurrent jobs setting is reached.

Round robin
NetBackup chooses the least recently selected storage unit in the list as each new job is started. If a storage unit is not available, or if no unit has available space, the job fails and is not queued. NetBackup does not continue to select the same storage unit.

Load balance
The Load balance option allows NetBackup to select storage units based on a capacity-managed approach. NetBackup avoids sending jobs to busy media servers.

The selection is based on the following factors:

The rank of the media server.
NetBackup considers the number of processes that are running on each CPU along with the memory thresholds on each server to determine the rank of a media server. If the free memory drops below a determined threshold, or if the number of running processes per CPU rises above a determined threshold, then the overall rank of the media server drops.

The number of jobs on the media server.
NetBackup considers the number of scheduled jobs on each media server.

Whether the media server has enough disk space to accommodate the estimated size of the image
NetBackup estimates the size of any new or current jobs on each media server and determines whether the jobs will fit on a given volume. NetBackup estimates the amount of space that the job may require, based on previous backup history. If no history is available, the high water mark for the storage unit serves as a guide.

When is the Load balance option available?
Load balance cannot be selected for a storage unit group that includes a BasicDisk storage unit. Also, a BasicDisk storage unit cannot be included in an existing storage unit group with Load balance enabled.

The status 129 Disk full error will occur using the first 3 options no mater how the configuration is setup. NetBackup will poll those devices based from the low and high water mark settings on the Disk Storage Unit but the disk is always consider available from the operating system and there for it will not fail over to the next storage unit in the storage group.  The Round robin option would provided the ability to have a failed job retry and then the other storage unit would be selected to

The Caveat
There is one situation where this configuration will work.  In the configuration of the DSU there is a parameter called "Maximum concurrent jobs". If the DSU is actively backing up and its "maximum concurrent jobs" limit is reached, then it is considered "busy", and a storage unit will then select the next storage unit defined on the list.

To prevent the status 129 from occurring the configuration for the disk staging schedule to run and perform duplications should be decreased to perform the duplications on a more regular/frequent schedule.  The other option to prevent the error from occurring is to setup regular Disk storage units and then use vault or another means to duplicate the images from disk to tape.  By default in NetBackup 6.5.x there is a feature to allow disk spanning this is enabled and can be set for the Master server and Media servers.  The setting is found under host properties of the Master/Media servers on the Media tab.  When the Disk storage unit is setup as a temporary staging location this feature is not supported.





Legacy ID



323882


Article URL http://www.symantec.com/docs/TECH87559


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