Speed performance

[PROSANJIT MALLICK]

Hi,
I have HP-9000 K570 server with HP-PB & HP-HSC
SCSI cards. What will be the performance difference if I connect my DLT 7000 to HP-PB
or HP-HSC?

Thanks & Bye.

[tony j. podrasky]

Maximum performance under average conditions: HP-PB F/W = 12Mb/s, HSC F/W = 16Mb/s.

More importantly is that the DLT 7000 *MUST* be on a channel by itself.

Next, to achieve such bandwidths you will need to keep the bus saturated. Trying to backup a 5Mb/s disk to a 12 or 16 Mb/s tape drive does not work. The drive winds up doing a "backspace" so that it can reach streaming speeds for the next data transfer.

If you have a good-sized chuck or memory, you'd see better performance by dumping the disk to memory and then copying it to tape.

Even better is the use a software package that will allow you to interleave dumps from several disk systems simultaneously, thereby achieving the desired thruput.