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Slow backup to tape

Hi,

We're having some trouble backing up virtual and physical servers to tape. We're not getting the speed it should get and it takes up a lot of time to back up the environment. 2,63TB of data takes up more than 24 hours. 

Information about job, tape & tape drive:
Tape type: HPE LTO Ultrium 6 6,25TB MP RW
Tape Drive: MSL 2024
Compression: Hardware
Encryption: None
Verify: Yes

These backups are going through the internal network within the domain. The average backup speed is 4,300MB/m (which is way to slow)

When we backup locally on the backup server (for example the D:\ drive where the incremental disk backups are saved on the backup server) it gets to a speed of 10500MB/m. Which is understandable considering it's a straight connection to the tape drive.

What did we do to try and resolve it:

* Checked the compression
* Checked encryption
* Replaced tapes for new tapes
* Resetted the tape drive
* Updated Tapedrive firmware
* Checked out the network for inconsistencies (not found), file transfers via other apps around 126mbs from server to server)
* Job from VM on hyper-visor to tape (around 2,900 MB/m)
* Local disk to tape (between 10500MB/M and 13500MB/M)
* VM to disk on the backup server (Around 6200MB/M)

Help would be appreciated.

 

2 Replies

Re: Slow backup to tape

The tape will shoe-shine. Stop/start/stop/start if it is backing up individual files, and this isn't anything you can control. If you're backing up a single large file, then the drive will write as fast as it receives the data. This explains why you're getting very fast transfer speeds on the local BE server.

So, unless you're backing up those VMs as VMs, and not targetting individual drives, those are kind of the speeds you can expect.

Re: Slow backup to tape

We're backing up to LTO-7 and see speeds of 2,300 MB/min!

I would change the hardware compression to software, this uses the remote agent to compress the data before it's sent over the network, improving overall speed.

You can also play around with the tape block size, buffer size, buffer count and high water count. There's info on this in the administrators guide.