Hi all,

I have some trouble with backing up large files to tape, or even to disk.
If I backup smaller files eg 1GB there is no problem, but if I backup
larger files, eg 30GB the throughput drops to about 4.5MB/s.

As I figured out, the problem comes from reading the disk. I used a tool,
diskperf which shows me the throughput while reading the disk. If I read
several smaller files, I get a throughput of about 104MB/s, while I get
just about 2,8MB when reading a 30GB file.

With TSATEST I get on both the large and the small an Effective MB/min:
3678.64 (61,3MB/s)

If I do a backup to disk with nbackup, I get with the small files a
throughput of 1318.56 MB/min (21.9MB/s), and with 30GB a throughput of
290.15 MB/min (4.8MB/s).

System: Dell PE1650 1GB Ram
QLogic HBA 2340 EMC CX300

Linux OES SP2 with up to date patchlevel.

Does anybody have a clou where I need to dig ?

Thanks for your help