8.6 Backing up less data per job

[572707725]

I've read many support documents and this entire thread in trying to get an idea as to why I'm seeing what I'm seeing.

I have 2 servers at 2 different sites not on the same network doing the same thing.

Both servers are Windows 2000 SP4, running Backup Exec 8.6 (installed from the same CD). Both are using DDS4 tapes to backup data.

Both sites need to backup approximately 35GB of data. This has been fine for months up until a few weeks ago. Site 1 hit a maximum capacity of tape, and was asked for a 2nd tape. This is fine, as we evaluated what needed to be backed up, made the changes and they are now backing up 18 GB of data.

Site 2 hit a maximum tape capacity at 32GB of data, causing a request for a 2nd tape. I was able to reduce the amount of data backed up to 22GB.

The issue is this - At Site 1 - they cannot go past the 21GB mark without requesting a 2nd tape. I've replaced the tape drive, bought new tapes, reinstalled 8.6 clean, and installed the version 10 Eval to a new directory - no help in any case. 21GB - new tape.

At Site 2 - they back up to 25GB and request a new tape. I've tried brand new tapes only here - same issue.

So, my obvious question is this - why were both sites backing up over 30GB of data daily for weeks at a time, run into a capacity issue, are now backing up LESS data, and still requesting 2 tapes?

Site 1 has new hardware - new install - new tapes
Site 2 is the same config as it was last month when it worked fine - only new sealed tapes were used to fix an assumed bad tape issue.

Thank you very much in advance for your time.

[Ken_Putnam]

What kind of tape drives?
What kind of media?
Have you reset the stats, and looked at how many soft and hard errors the drives accumulate in one or two nights?
Have you tried setting the jobs to SW compression only to see what kind of compression they are getting now?

[583507064]

The 2 sites are using the little Sony DDS4 tape drives. I believe both are on SCSI chains.

They also use the Sony DDS4 4mm 20/40 tapes

The site I'm working on has had the software uninstalled and reinstalled completely. First was a reinstall of 8.6. Then a remove and install of 10.0 Eval. This was removed and 8.6 was reinstalled when Gateway sent us a new tape drive. I dont have the errors listed, and I suppose I'd need a direction on where/how to view these

I've tried all compression options at both sites.

[Ken_Putnam]

If both sites are getting more than 20GB per tape, then compression is working

Remember that 2:1 compression is purely a marketing thing, not an engineering thing (See http://seer.support.veritas.com/docs/199542.htm ) , and the only way to know how much data will compress is to compress it.

25GB on a 20GB tape is about 1.25:1, my rule of thumb is 1.3:1, so that's not too bad. The other system with 21GB on a 20 GB tape is only about 1.05:1, which is pretty bad, but it IS compressing so the data is probably just the wrong type

[583507064]

I guess that is where my confusion lies.

Site 1 was backing up approximately 36GB of data before it asked for a 2nd tape. I removed approximately 18 GB of data that was deemed unnecessary. Now at 21 GB, it asks for a new tape. I would expect to see about 30 to 34GB of data backed just like we did a few weeks ago, not 21. What happened to being able to backup 36GB?

Site 2 was similar. They capped out at 31. I removed about 6 GB of log files, and now at 25 GB they're requesting a new tape. What happened to being able to back up 31 GB?

I'm just not sure how that makes sense. I've been told to upgrade my software, but I can only assume that 10.0 Eval will function the same way 10.0 with a license will - and I've already tested that the amount of data backed up does not increase per tape with the new software.

Does this seem logical?

I guess the biggest concern is that the clients feel that they have a sufficent tape backup system due to the fact that they were backing up more data before, and don't buy the fact that they need a bigger tape system to back up less data...

[Ken_Putnam]

Oh, sorry 'bout that.

Nothing has changed, except that you have reduced the amount of data to be backed up? No new drivers for the drive or SCSI card?
No new firmware (all of which chould INCREASE) capacity not chop it like that)

Just for grins, have you tried creating a completely new job and select list? probably won't help, but it may.

Are the jobs Overwrite or append?

[Kaushal_Dahanay]

I have the same issue. Was the issue in this thread sloved? My customer has the same version of BE and has the same problem. Customer has 20/40GB DAT drive and uses DDS4 tapes. Was able to backup 26GB before. Since two weeks back when it hits anywhere between 22-25GB its asks for a second tape. The backup is set to overwrite. I have also used blank tapes but same problem. Any suggestions??