performance tunning on NBU

[kwleung330]

Hi All

I am using the IBM library with LT04 which directly attached to Solaris 10 by FC cables and some performance issue on NBU, can anyone advise?

On O.S level (backup server), do the ufsdump
# ufsdump -0uf /dev/rmt/0cbn /

the speed is 20MB/s.

On NBU , do backup the (backup Server)
the speed is 8MB/s.

How can i fine turning on NBU 6.0 with MP5 that can make the speed faster?

 

[Martin999]

You can try playing around with the block size, 256 is I think fairly compatable with LTO4. You can alos adjust the number of bufferes. THere is a tech note on it explaing the details.

Tape drives are now getting very fast, quicker in fact than disk. An LTO3 drive (IBM) has to write at a minimum of 40MB/s to stream, else it stop /starts. LTO4 need to go even quicker to stream (can't think of the exact figure.

The problem is fairly simple, you cannot get the data off the servers quick eoungh. Windows servers are even harder, due to (generally) lots of small files. According to a good source of information at Imation, most companies cannot drive LTO2 quick enough, let alone 3 or 4. Those who do, tend to backup to a VTL, and then stream off that.

Dependant on what the files on the server are, how busy it is, the power of it and the backup server/ media server, you may not be able to reach the required speed. Stop/ start is not good, damages tapes and drives. You could try using LTO3 tapes, this will slow the requirements down, or use a different technology. Storagetek drives are designed to stop/start, but are expensive.

Martin