cancel
Showing results for 
Search instead for 
Did you mean: 

Backup tapes: LTO3: Half used capacity

michaelbloch
Not applicable

Good Day

Using backup exec 12.5 SP5 on Win2003 server with HP Ultrium 3 SCSI tape device.

Our LTO3 tapes only get half used but indicate full. Tried software compression on/off - no difference. Tape drive doesn't support H/W compression.

Regards

15 REPLIES 15

CraigV
Moderator
Moderator
Partner    VIP    Accredited

Hi Michael,

I'd suggest the following:

1. Use HP Library and Tape Tools (HP LTT) to update the firmware on your tape drive.

2. Get the latest drivers (and maybe any available updates too!) for Backup Exec 12.x and install them. Once done, run the Device Configuration Wizard and install the latest Symantec drivers. Try a backup job again, and post the results here...

 

Laters!

ZeRoC00L
Level 6
Partner Accredited

When I see the screenshot it looks like there is not used any compression.

What kind of data are you trying to backup? Maybe it is uncompressable data?

CraigV
Moderator
Moderator
Partner    VIP    Accredited

If data is not compressed, it is 1:1 which means that the tapes would fill up as much as possible...not stop at 50%.

ZeRoC00L
Level 6
Partner Accredited

Used capacity is 390GB, so that is the uncompressed media size.

MOHAMED_PATEL
Level 5
Partner Accredited Certified

LTO3 drives have on-board compression - Compression on a software level, increases server overheard.

ZeRoC00L is right on the money - depends on the data - Vote +1

so is CraigV - update tape firmware - Vote +1 - have your vendor do this if still in warranty.

Larry_Fine
Level 6
   VIP   

Compression is irrelevant.... you should ALWAYS be able to get the native capacity of the media.  Michael should be able to get AT LEAST 390 GB on that tape.  He is only getting 243 GB and the tape is reporting that it is full.

Michael, has it always been this way or did this isse develop recently?  Have you contacted HP?

pkh
Moderator
Moderator
   VIP    Certified

390GB is the native capacity of the tape.  When you format the tape and write to it, there are going to be overheads, so you would not get 390GB of uncompressed data onto the tape.   This situation is like buying a 500GB harddisk and then seeing only 400+Gb after formatting it.

ZeRoC00L
Level 6
Partner Accredited

Have you tried to (quick) erase a tape and then tried to make a backup ?

UFO
Level 6

Have you tried to get the same tape from your supplier and go step-by-step with the setup?Maybe it is fault by manufacturing.

UFO
Level 6

Could be true. BTW, how (physically and logically) LTO is being formatted?

Larry_Fine
Level 6
   VIP   

I suggest contacting HP tech support for an analysis of your drive and media.

1.       After installing L&TT, open the utility to scan the bus

2.       Once the drive is found under the 'Drives' hive, select it

a.       If the drive is not found, stop any application(s) that may have it locked

b.      Eject any media from the drive

3.       Select the 'support' icon from across the top of the screen

4.       Select the 'Extract Device Data' option and wait for the process to complete

5.       Select the 'Save Support Ticket' option and chose a location to store the log

CraigV
Moderator
Moderator
Partner    VIP    Accredited

Hi,

 

Any news on whether or not this is sorted out?

 

Thanks!

zaxbg
Level 2

Hi,

Did you try cleaning the HP device, and maybe downloading some testing tool from HP.

I recently had same problem with Quantum LTO3 drive, it was writing less data then tape capacity. I noticed that the number of soft write errors was huge(about 300 000).

And it was a HW problem with the drive.

 

Best Regards 

James_Winslow
Level 5

Have you tried with other tapes to see if this is could be the cause of drive head error or tape bad sector ?

Mike_T1
Level 0

I have the same issue the backup written is only Half. If I go back to the old tapes its fine.