backup slow

[hpuxhelp]

it took approximately 2 hours to do back up data on to tape of 1GB of data. Is it normal, or what can i do to improve the performance

[Patrick Wallek]

What kind of data are you backing up? Is it just a few larger files or is it a whole bunch of little files? What kind of tape drive are you backing up to? What method are you using to do the backup?

We really need some more information before we can effectively answer you.

[Pete Randall]

Steven,

That sounds slow to me, but, like Patrick said, we really need more data to give you a decent answer.


Pete

[hpuxhelp]

mostly large files
using dlt compag tape
and we use tar as the method

[Patrick Wallek]

tar is not the most efficient thing to use for backups and there is really not a whole lot you can do to speed it up.

A DLT should run faster than that, but if you are not able to feed data to the tape drive fast enough then the tape drive will lots of "shoe shining" and slow you down.

How is the tape drive attached? Is it a Fast-Wide, LVD, Single-ended SCSI? Is it on the same SCSI bus as the disks? If it is on the same bus as the disks then this will slow you down even more. Any high-speed high-capacity tape drive should really be on its own SCSI bus with nothing else on it.

[Pete Randall]

I think fbackup would be a better choice than tar. You've got to keep enough data going to the DLT drive to keep it in streaming mode, otherwise it has to continually back up the tape and reposition itself.


Pete

[T. M. Louah]

Using fbackup with -c option specifying config file, works fine & usually increases performance try it with :
blocksperrecord 64
records 64

More info are found in fbackup man pages.
Cheers
T??

[Frank Slootweg]

As mentioned, do not use tar(1) with DLT, but use at least fbackup(1M) (with the mentioned or higher blocksperrecord setting), or better use a real (and supported) backup product like HP's OmniBack / Data Protector or a similar Third Party product.

BTW, what *type* of DLT do you have, i.e. DLT4000, DLT7000, DLT8000?