backup performance

[Former Member]

We are using RMAN to backup the database and we've got below benchmark for backup performance:

DB size: 10T (3.4T table with compression enabled, 4.8T index without compression enabled, 1.8T others).

RMAN compress backup to: 2T

Backup with 10 channels, it will be completed within 6 hours, than the average backup ratio is 50MB/s/channel.

We are monitoring the system and we did not find bottle-neck except those 10 single CPU/Core which is dedicated for each backup channel.

Anybody can provide the your experience (or oracle best practice) for backup ratio under this situation? Is 50MB/s/channel a fair number?

If you do not enable compress of RMAN, pls provide the number.

Thanks in advance,

James

[volker_borowski2]

Hi,

you might want to try around with compression algorithm "medium".

(Caution: Requires ACO license when bought from Oracle)

The default might be to CPU costy if you backup to tape.

This could make tape streaming stall because of data being fed too slow

which you do not like to have.

Check out rman command

configure compression ....

Volker

[Former Member]

Understood, Volker.

First of all, I wan to know whether this is a good performance even it can be improved. We need a benchmark to persuade management team not to set 10 times faster as the target.

Thanks again,

James

[stefan_koehler]

Hi James,

> First of all, I wan to know whether this is a good performance even it can be improved

How should we know? We know nothing about your environment like backup device, used buffer settings, used OS, used I/O settings and so on. It is like "I want to know the best car" without specifying what you need.

Just as an example check out my blog post here:

Regards

Stefan

[Former Member]

In your testing case, 125MBps - 206MBps / channel is a good reference for enterprise storage.

Point will be rewarded.

[stefan_koehler]

Hi James,

> In your testing case, 125MBps - 206MBps / channel is a good reference for enterprise storage.

No, it is not. It is about synchronous I/O requests. The picture would be totally different (with the same storage), if your OS can do asynchronous I/O.

Regards

Stefan

[Former Member]

Here is one, but quite old...

www.oracle.com/au/products/database/311357-132408.pdf