MSL 6030 Ultrium3 data speed transfer

[ATHANASOPOULOS PANAGIOT]

Our configuration is:

A rx8620 HP-UX 11.23 Server
SW Cisco MDS 5500
MSL 6030 with Ultrium 3 tapes.
The MSL router is E1200-160.

We use dd command to make the backup to the MSL6030 Backup Library.

With this method we achive data speed transfer below 50MBps, the same results as when we use Ultrium2 tapes.

But when we use ttl ( the HP tool) we have a speed of 100MBps, this method transfer the data from the memory to the MSL Library.

As we continue the tests we find that from /dev/zero to the MSL library the speed is 75MBps.

Is there a better way to run dd command? We want to reach the 100MBps speed because our database is huge.

Thanks in advance

[Uwe Zessin]

You can try to play with the "bs=" option, but you might not reach 100 MegaBytes/second read throughput from physical disk drives.

The data from "ttl" or "/dev/zero" comes from cpu/memory, so it is not surprising that you see higher values.

[ATHANASOPOULOS PANAGIOT]

We made many tests with different "ds=" options and we only saw a little bit of improvement. Do anyone has anything to suggest?

[Richard Bickers]

You really need to use a recognised backup application to get the most out of your system. They are optimised for streaming devices and use all the appropriate buffering, transfer sizes etc. They don't come for free (!) but that's what you'll need to do to make the most of your hardware.

For automation customers we recommend taking a look at our EBS (Enterprise Backup Solution) compatibility matrix for advice on best practice system configuration. That's available from the HP web at //h18000.www1.hp.com/products/storageworks/tapecompatibility.html. Look for the link to the EBS matrix.