Re: rman backup restore questions and problems

From: VinceM <vincem_at_nospam.com>
Date: Wed, 27 Nov 2002 11:21:19 -0500
Message-ID: <1038414055.942063@nnrp1.phx1.gblx.net>

"Tilwen" <tilwenbr_at_netscape.net> wrote in message news:8a41a7df.0211261755.45874920_at_posting.google.com...
> I have a database about 100 gb in size. I do a full database backup
> every night. The other day, we had some corruption after a crash and
> it took a long time to do a restore on a tablespace, say 12 hours. I
> looked this up on metalink and there is a bug about the CKP table
> being over 10,000 records. They sent us a script to clean up this
> table. Well, that didn't help. I'm doing a test restore right now and
> it's going to take just as long to do it. The tablespace is only about
> 8gb in size. here is the commands we use to back it up.
> run
> { #ENV is case sensitive
> allocate channel t1 type 'sbt_tape' parms
> 'ENV=(DSMO_NODE=rx_r50,
> DSMI_CONFIG=/usr/tivoli/tsm/client/ba/bin/dsm.opt,
> DSMO_PSWDPATH=/usr/tivoli/tsm/client/oracle/bin,
> DSMI_DIR=/usr/tivoli/tsm/client/ba/bin,
> DSMO_AVG_SIZE=1000)';
> allocate channel t2 type 'sbt_tape' parms
> 'ENV=(DSMO_NODE=rx_r50,
> DSMI_CONFIG=/usr/tivoli/tsm/client/ba/bin/dsm.opt,
> DSMO_PSWDPATH=/usr/tivoli/tsm/client/oracle/bin,
> DSMI_DIR=/usr/tivoli/tsm/client/ba/bin,
> DSMO_AVG_SIZE=1000)';
> allocate channel t3 type 'sbt_tape' parms
> 'ENV=(DSMO_NODE=rx_r50,
> DSMI_CONFIG=/usr/tivoli/tsm/client/ba/bin/dsm.opt,
> DSMO_PSWDPATH=/usr/tivoli/tsm/client/oracle/bin,
> DSMI_DIR=/usr/tivoli/tsm/client/ba/bin,
> DSMO_AVG_SIZE=1000)';
> allocate channel t4 type 'sbt_tape' parms
> 'ENV=(DSMO_NODE=rx_r50,
> DSMI_CONFIG=/usr/tivoli/tsm/client/ba/bin/dsm.opt,
> DSMO_PSWDPATH=/usr/tivoli/tsm/client/oracle/bin,
> DSMI_DIR=/usr/tivoli/tsm/client/ba/bin,
> DSMO_AVG_SIZE=1000)';
> backup database;
> sql "alter system archive log current";
> backup archivelog all delete input;
> release channel t1;
> release channel t2;
> release channel t3;
> release channel t4;
> }
> here is the restore script.
> run
> { #ENV is case sensitive
> allocate channel t1 type 'sbt_tape' parms
> 'ENV=(DSMO_NODE=rx_r50,
> DSMI_CONFIG=/usr/tivoli/tsm/client/ba/bin/dsm.opt,
> DSMO_PSWDPATH=/usr/tivoli/tsm/client/oracle/bin,
> DSMI_DIR=/usr/tivoli/tsm/client/ba/bin,
> DSMO_AVG_SIZE=1000)';
> sql "alter tablespace d_cqm offline immediate";
> restore tablespace d_cqm;
> recover tablespace d_cqm;
> sql "alter tablespace d_cqm online";
> release channel t1;
> }
> i do realize that I should being doing the restore in parallel also,
> but I don't think that that would cut down the restore into a 3rd. it
> might, but I doubt it.

>

> I do have an idea but I want to run this by some of you. we are using
> adsm in conjuction with rman. Would it be better to put filesize
> paramater in the backup script. So that when doing the restore, rman
> doesn't have to read through so much of the backupset to get only a
> small portion of the backupset? He only has to read more backupsets,
> but they are a lot smaller(5 to 7 gb compared to 15 and 20 gb), so
> rman should read them faster.

>

> I have done a search on here and looked on metalink, and came up with
> no leads. I'm posting here to get some insite maybe. I'm actually
> thinking that I will have to do a lot of testing to get something like
> this right. Yes, we should have been doing test restores a along to
> catch this. I know this, and have said this same thing before. We
> finally have gotten enough hardware and such to create a test DB, so
> things like this can be resolved before they are a production issue.
>
> thanks.

This may not be an RMAN be the issue. How long does it take to do a restore of a file using OS utilities? We've found that restores take about 4 times longer than backups using RMAN or tar (we are AIX 4.3.4). Received on Wed Nov 27 2002 - 10:21:19 CST