Growing Oracle DB taking long time to backup!

[former_member211967]

Dear Experts,

Our Database (BI) has grown upto 900 GB in nearly one year. Given that time frame, weekly offline backup inreased since the database is growing.

I was reading few posts and some search and came to know that the backup should not take that long. My backup is running over 12 hours. As per few blogs, article, and search, backup speed can be 4TB per hour. In my case, this is not the case.

I'm backing up locally in the file system with a different NFS mount.

What would be the best approach to take to reduce the number of hours is currently taking? I'm compressing the backup. Should I spilit the backups? Is it even possible? If yes, would it help in my case? Should I not compress it?

Your help is really appreciated!

Thanks,

[Former Member · Accepted solution]

As I know, NFS is only used for slow storage.

For full speed backup, one would recommend Fiber based media.

Regards,

[markus_doehr2]

> I was reading few posts and some search and came to know that the backup should not take that long. My backup is running over 12 hours. As per few blogs, article, and search, backup speed can be 4TB per hour. In my case, this is not the case.

The first thing to check is: Is your hardware capable of backup up at that speed? a GBit network can handle - theoretically - a maximum of 80 MB/sec if the target system (fileserver, tape etc.) is able to handle that speed.

Why don't you switch your backup method to RMAN and incremental backups?

Markus

[former_member211967]

Thanks everyone!

Markus,

Good point. We are on 10gig NIC cards shared accross the 5 virtual systems. Running BI, ECC, BI Java, and more.. We are using dbacockpit and that is the reason it is using brtools. Do you think if we switch it to RMAN, it would enhance the backup speed?

Thanks,

[markus_doehr2]

You can, of course, continue to use the br*tools, they can be configured to use RMAN:

http://help.sap.com/saphelp_nw70ehp1/helpdata/en/fd/dba41eb4aa2943b88c46d06f693d2e/frameset.htm

Markus

[former_member211967]

Hi Markus,

I did not know that. I will defnintely try this out to see if it makes difference. Do you know if RMAN is faster than brbackup?

Thanks,

Edited by: SAP_BASIS_ORA on Jan 24, 2011 3:36 PM

[markus_doehr2]

> I did not know that. I will defnintely try this out to see if it makes difference. Do you know if RMAN is faster than brbackup?

RMAN can do incremental backups - so the amount of data is less

Markus

[former_member211967]

Hi Markus,

RMAN can do incremental backups - so the amount of data is less

True. However, i'm worried about the full weekly backup (over the weekend). Incremental backups are working using brtools via brbackup. Of course I want to enhance the incremential as well.

Thanks,

[Former Member]

Do you know if RMAN is faster than brbackup?

RMAN can be faster, as it only saves blocks, that are containing data. If you use incremental backups only blocks that were changed since the last backup will be saved. But in case of a restore you will have to restore from several backups, which can lead to significant higher restore times.

You should be thinking about moving away from offline backups and only doing online backups for systems this large. Or you do a major change in your backup strategy. On some large system we do split-mirror backups. This means you mirror the disks on the storage side. In case of an offline backup the database is shutdown (we even leave the SAP instances running), the mirror is split and the database is restarted. Then a backup server attaches the disks and does the backup. This way, we can do offline backups with only 10 minutes of downtime even on multi terabyte systems. But this solution is very complex and costly. Nowadays we mostly do online-split backups because to sync all jobs for a downtime window is too cumbersome on the busy systems.

For a 900gb system even with a lan backup (given > GB-lan interfaces) the backup should be possible within 2-4 hrs, but this could mean you have to tune your backup environment (SAN / tape access).

Cheers Michael

[former_member211967]

Hi mho,

Thanks for the reply. What type of tuning or what knid of steps can I take to enhance the speed in SAN storage? As per the split goes, If I'm undertanding it right, you can split the backup into multiple file system such as 4 to reduce the time consuming? Is that right? Split in this case, is it same as what is called Parallel?

Thanks,

[Former Member]

What type of tuning or what knid of steps can I take to enhance the speed in SAN storage?

I really cannot help you there, if you feel the performance is not good enough then talk to your SAN/network admins.

[Parallel Backup|http://help.sap.com/saphelp_nw70/helpdata/en/88/a2a041a5d4af4db168992639d65d3b/frameset.htm] and [Split Mirror Backup|http://help.sap.com/saphelp_nw70/helpdata/en/68/b72d86db13c642bb6e17b83b75f598/frameset.htm] are not the same.

By the way looking up the link to the documentation i stumbled on [Backup of Large Oracle Databases|http://help.sap.com/saphelp_nw70/helpdata/en/b5/a25ac61a115d47b072dc79b299bc13/frameset.htm]. However most of the content has already been discussed here. So maybe you stick to the advice from Markus to try rman first. I was not to add more confusion. I just wanted to add, that there are ways to improve backup speed if your database grows larger.

Kind regards, Michael

[former_member211967]

Hi mho,

You are definitely not confusing. It is better to understand all the prospective. I will be trying all the options that are possible and choose the best one.

I will be starting with parallel backup. If I were to take this route, don't I have to change the following parameters? Am I correct?

*Parallel backup:*
exec_parallel = 4

*Multiple Locations*
backup_root_dir=/oracle/<SID>/sapbackup/backup1
backup_root_dir=/oracle/<SID>/sapbackup/backup2
backup_root_dir=/oracle/<SID>/sapbackup/backup3
backup_root_dir=/oracle/<SID>/sapbackup/backup4

Thanks in advance!

[mohammed_anish]

hi,

if you want to backup using rman to disk,set the following parameters,

backup_root_dir=(/oracle/<SID>/sapbackup/backup1,/oracle/<SID>/sapbackup/backup2,/oracle/<SID>/sapbackup/backup3,/oracle/<SID>/sapbackup/backup4)

disk_copy_cmd = rman

rman_channels = 4

rman_filesperset = 0

Regards,

Anish

[nirmal_konchada]

Hi,

Yes...your backup would take time as its on a NFS which works over the network.

For faster solution go for a LTO or a 3rd party backup solution.

Regards,

Nirmal.K