What are you doing with Oracle
You didn't say what version of Oracle you are using.
Version 10 uses an additional recovery method called Flashback Recovery.
Its configured on the MIS instance, but it too is prone to generating a
lot of errors. I am digging into how RMAN, Flashback, NetWorker all
work together.
We are using 7.2.1 locally, have upgraded one site to 7.3.2... It is
going strong, although has a tendency to flash RED icons indicating a
failure over the silliest errors, which aren't exactly a back-up
failure. Just an indicator that we do not use VSS. SO WHAT we don't use
VSS... "/Shaking Fist to the sky" that doesn't mean the backup failed.
/Rant OFF
Semper Fidelis et Paratus, /ALE
> -----Original Message-----
> From: EMC NetWorker discussion
> [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On Behalf Of George Sinclair
> Sent: Thursday, November 30, 2006 2:09 PM
> To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
> Subject: [Networker] Oracle RMAN backup questions
> Importance: Low
>
> Hi,
>
> Several questions here on RMAN Oracle backups via NMO. We're
> running Oracle 10g, with NW 7.2.2.
> Our drive target sessions are set to 5. These are SDLT 600 drives.
>
> Some of these questions may be moot since there's so many
> variables that will determine what settings work best for
> your shop but really just wanted to get an idea of what
> others are doing and what, if any, bad experiences, pit falls
> or suggestions you could offer.
>
> In testing Oracle backups and recovers, we've been playing
> with a rather small test database. We've tried multiple
> channels, and multiple filesperset, and we don't really
> notice any major performance difference, but obviously, the
> more channels, the more concurrent streams we can send to the
> device, so it's more efficient and doesn't have to
> continually stop and then back up another like it would if we
> had channels set to 1 where it would go one at a time.
> Also, increasing filesperset helps in this area , too.
>
> Clearly, the more channels you set, the more save sets you
> end up with and thus the more save sets will be interleaved
> to the tape and the longer recovers will take, so there's a
> trade off between increased write speeds versus recovers.
> BUT, the more save sets you break the Oracle backups into the
> smaller those save sets, and that could be a good thing, but
> the more filesperset, the larger those savesets, too. Hmm ...
> OK, all fine and well, but:
>
> 1. Does more filesperset also affect recover time in the
> same way that more save sets (channels) to the same tape does?
>
> 2. During normal (non-Oracle) backups, how many files does
> NetWorker send in a single saveset?
>
> 3. Let's say you had a database of 100 files, maybe 70 GB
> total. If you set filesperset 1, and had 1 channel then you'd
> end up with 100 save sets on a full which sounds kinda dumb.
> On the other hand setting filesperset 100 with 1 channel
> sounds ridiculous as well. So, how about 2 channels with
> filesperset 5.
> That would take 20 save sets on a full, maybe only 5-6 save
> sets on an incremental. Does that sound reasonable or would
> it be better to crank it up to 5 channels? Our devices are
> set to handle 5, so it's not gonna need another drive.
>
> We have the Oracle client's parallelism set to default 4
> (NetWorker), so I imagine we can't increase the channels
> beyond 4 unless we change that value. This machine has 8
> cpus, plenty of memory, so maybe we can increase that. Since
> our test database is so small, though, we really don't have a
> good feel for what will and won't work so well, but I was
> thinking that if we're seeing decent write speeds, and decent
> recover times at say 2 channels with filesperset 5 then maybe
> just leave it at that?
>
> 4. Should the channels be set to 1 when recovering?
>
> 5. Should we use regular differential backups (like level 1
> every night until the next full) or a cumulative backup?
>
> Thanks for any horror stories or suggestions.
>
> george
>
> --
> George Sinclair - NOAA/NESDIS/National Oceanographic Data Center
> SSMC3 4th Floor Rm 4145 | Voice: (301) 713-3284 x210
> 1315 East West Highway | Fax: (301) 713-3301
> Silver Spring, MD 20910-3282 | Web Site: http://www.nodc.noaa.gov/
> - Any opinions expressed in this message are NOT those of the
> US Govt. -
>
> To sign off this list, send email to
> listserv AT listserv.temple DOT edu and type "signoff networker" in
> the body of the email. Please write to
> networker-request AT listserv.temple DOT edu if you have any
> problems with this list. You can access the archives at
> http://listserv.temple.edu/archives/networker.html or via RSS
> at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER
>
To sign off this list, send email to listserv AT listserv.temple DOT edu and
type "signoff networker" in the body of the email. Please write to
networker-request AT listserv.temple DOT edu if you have any problems with this
list. You can access the archives at
http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER
|
