RE: RMAN restore times

Of course, if you run multiple RMAN channels (requires Enterprise Edition) to multiple tape drives, you should be able to reduce the backup/restore time considerably. Here are some specs I pulled off of storagetek.com - looks like you can also speed things up significantly with LTO-3:

Spec Summary
  LTO Gen 1
  LTO Gen 2
  LTO Gen 3

Capacity, native (uncompressed):
 100 GB
 200 GB
 400 GB  

Data transfer rate, native (uncompressed):  15-16 MB/sec
 32-35 MB/sec
 80 MB/sec  

Interface:
 Single port Ultra 2 SCSI
 Single port Ultra 3 SCSI
 Ultra 320 SCSI

-----Original Message-----

From: Allen, Brandon
Sent: Monday, August 08, 2005 11:16 AM
To: 'somckit.khemmanivanh_at_weyerhaeuser.com'; Hallas, John, Tech Dev; Lora Martin; oracle-l_at_freelists.org
Subject: RE: RMAN restore times

Somckit,

We're using NetBackup 5.1 on an ADIC Scalar tape library with LTO-1 drives (or so I've been told from the admins - it's all behind the scenes to me), on which I typically get a little under 20MB/second for both backups and restores

At this rate, you'd be looking at about 15 hours for 1TB.

Regards,
Brandon

-----Original Message-----

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of Khemmanivanh, Somckit Sent: Friday, August 05, 2005 8:26 AM
To: Hallas, John, Tech Dev; Lora Martin; oracle-l_at_freelists.org Subject: RE: RMAN restore times

Thanks for your response, I have 2 questions/clarifications:

1. You mention "RMAN backyp from the mirror then re-sync". How is this possible? The mirror copy will be in hot mode, you have to recover the database to open it. Doesn't the database have to be open in order for RMAN to back it up? Did I miss something? If so can you clarify?
2. Regarding restore times, what times have people been seeing with RMAN? If you can post your tape technology that would be much appreciated. If we stick with BCV then it's really hard to beat that technology for restore times but can we get close?

Thanks!
-----Original Message-----

From: Hallas, John, Tech Dev [mailto:John.Hallas_at_gb.vodafone.co.uk] Sent: Thursday, August 04, 2005 11:53 PM To: Khemmanivanh, Somckit; Lora Martin; oracle-l_at_freelists.org Subject: RE: RMAN restore times

If I had BCVs available I would break the mirror then RMAN backup from the mirror then re-sync.
You have a 2TB database. Somckit takes 4 hrs to restore a 4Gb file. There should be / is a fundamental difference in resources or configuration between those 2 setups.

If you have BCVs etc I would expect you to have fast tape technology and the whole database should be restorable in maybe 4 hrs not just a 4Gb file.

One of the major determining factors in restore times I have seen is the time waited to load the required tape or the contention with other jobs. That is often not taken into account when the overall time is calculated.

John

-----Original Message-----

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Khemmanivanh, Somckit
Sent: 04 August 2005 18:21
To: Lora Martin; oracle-l_at_freelists.org
Subject: RE: RMAN restore times

Thanks for your feedback.

Yes, my main hesitation with the RMAN backups for such a large database was the restore times.

Why would a 4 GB file take 4 hours to restore? Contention for tape resources? Really slow tape drives, network?

Thanks!
-----Original Message-----

From: Lora Martin [mailto:lmartin_at_clubmom.com] Sent: Thursday, August 04, 2005 10:01 AM To: Khemmanivanh, Somckit; oracle-l_at_freelists.org Subject: RE: RMAN restore times

If you have BCV - I would use that. I have used EMC BCV... very fast... then go to tape from there. When we restored 4GB file using RMAN from tape on a 2TB system - the restore took 4 hrs

--

http://www.freelists.org/webpage/oracle-l

Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.

--

http://www.freelists.org/webpage/oracle-l Received on Mon Aug 08 2005 - 13:23:57 CDT