800 GB tapes and images 2

[Tech9801]

I have (10) 800GB HP Ultrium RW Data Cartridges (C7973A)
My backups are around 300GB each night, I manually change the tape out each day, I have a 2 week retention set on the images. My question is that Netbackup will not allow 2 300GB images to fit on a tape. I'm running Netbackup 6.0MP4
The image should expire before then but I've been having trouble were it asks for another tape to finish and the images are only approx: 300GB, two images should fit easily on these tapes right?

Thanks

 

[OHWS]

How many files are contained in the 300 gig of data? 100 files that makeup 300 gig of data compresses alot better than 1 million files of the same amount of data. Long and short of it is when it comes to compression the type and number of files is more important than the size of the overall data.

 

[Tech9801]

There were 663,020 files written to the tape for a total of 294GB.

This data ranges from users Excel,Word documents, and software.

Thanks

 

[Stumpr]

from the Media Manager Admin Guide: for NB 5.1 page 362

How NetBackup Selects Media in Robots
When NetBackup selects a volume in a robot, it proceeds as follows:
1. NetBackup searches the media catalog for a volume that is already mounted in a drive
and which meets the following criteria:
? Configured to contain backups at the retention level required by the schedule
(unless the NetBackup Media host property, Allow Multiple Retentions per
Media is specified for the server).
? In the volume pool required by the backup that is being performed.
? Not in a FULL, FROZEN, IMPORTED, or SUSPENDED state.
? Of the same density required by the requested backup and, in the case of a robotic
storage unit, in the robot requested by the backup.
? Not currently in use by another backup or a restore.
? Not written in a protected format. This is detected after the volume is mounted. If
the volume is in a protected format, it is unmounted and NetBackup resumes the
search.
2. If NetBackup cannot find a mounted volume that satisfies all of the conditions in
step 1, it checks its media catalog for any volume that is suitable.
3. If the media catalog does not have a suitable volume, NetBackup requests Media
Manager to assign one. Also, if a volume is at EOM (end of media), NetBackup will
request a new volume. This may happen even if the volume if not completely full
(because NetBackup received an EOM message from the drive).
Media Manager assigns a volume to NetBackup that meets all of the following
criteria:
? Is the correct media type.
? Is for the correct robot type (if applicable).
? Is located in the requested robotic peripheral (if applicable).
? Resides on the requested host.
? Is in the correct volume pool.
? Is not currently assigned (not already allocated to NetBackup).
? Is not expired (if an expiration date is defined in Media Manager).
? Has not exceeded the maximum number of mounts allowed.
4. If more than one volume qualifies, Media Manager chooses the volume that was least
recently used. NetBackup then adds it to the media catalog and assigns it the specified
retention level.
5. If there are no unassigned volumes of the requested type, the backup terminates with
an error indicating that there was no available media.


Bob Stump
VERITAS - "Ain't it the truth?"

 

[akcongo]

I use the same tapes in my shop. I average about 550gb per tape. Sometimes I get more but not very often. I think HP likes to advertise the tapes' compressed data capacity rather than their native capacity and we rarely get compression that good.