ADSM-L

Re: [ADSM-L] Two different retention policies for the same node

2009-03-18 17:55:41
Subject: Re: [ADSM-L] Two different retention policies for the same node
From: Steven Harris <sjharris AT AU1.IBM DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Thu, 19 Mar 2009 08:52:39 +1100
Michael,

I have two ideas about your problem.

Idea 1.  Create another domain for your high priority servers, with the 7
day retention period.  Move the nodes into this domain. Create new nodes
for these machines in the old domain with different names.  For machines
performing an "normal" incremental run two backups every day, one to each
node name.  For machines with too many files for that run a weekly
incremental to the longer retention domain.  For databases/tdp nodes run a
weekly extra backup to the longer retention domain.  Explain carefully to
management that the coverage of the longer retention period data now has
holes in it.

Idea 2.  The "7day" retention for offsite sounds like a simple-minded
notion of what might be nice to have.  What they really want is an
activepool but they aren't comfortable with it.  Create an activepool daily
for the high priority data.  Send it offsite to disk.  Set the DB
expiration to not less than 7 days.  Set activepool pending delay to 7
days. Continue to send your normal copypool tapes offsite.  Have a small
library offsite too.

If you have a disaster all your active data is instantly available.  If you
need day -n, restore the db for that day and the activepool data for that
day will be available. Alternatively use your small library and restore day
-n data from the usual copypool tapes.

One loose end.... if your ERP is SAP, the backups are actually TSM
archives.  I'm not sure how Activepools work with archives and don't have
the time to look it up now.

Regards

Steve.


Steven Harris
TSM Admin, Sydney Australia



                                                                       
             Michael Green                                             
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On Tue, Mar 17, 2009 at 11:18 PM, Conway, Timothy
<Timothy.Conway AT jbssa DOT com> wrote:
> Is this to avoid having two copypools?  That's a reasonable goal.   I
> have only one copypool, which is my DR offsite pool.  Just make your
> onsite copypool an offsite pool, and you can give them 25 times better
> than they're asking for.

No, the idea is to keep offsite 7 days history for very few most
important servers (ERP, HR) on disk.  I don't much care if that will
be primary pool or copy pool. As long as I can get my data back off it
- it's fine.
Today, I manage 3 servers here and am sitting on 0.5 peta of backup
data. There is no point to have all that data (most of which is
inactive) at DR site (we do have offsite vault though). At DR site we
want to keep preconfigured turn-key ERP, HR servers, a preconfigured
TSM server with its database and SAN or NAS attached disk that has the
7-days history. I have yet to work out how and by what means my 140GB
database will get to DR site on daily basis. Maybe we will use a
dedupe or maybe we will open a separate TSM instance  just for these
few servers so that the DB that we will have to copy to DR site will
be as small as possible. Also the smaller  DB, the better in DR
situation.

> Unless most of the data changes every day, the difference between 7 days
> and 180 days worth of copypool is remarkably small.

It can be big. ERP server backs up over 100G nightly. I guess it
dedupes pretty well though.


> If you have no copypool at all, the whole thing is a farce.
> If they're wanting fast portable full restores of a subset of the total
> nodes, how about backupsets?  Make a nodegroup containing all the nodes

Backup sets are fine as long as tey are relatively small and you don't
have to generate them on daily basis. Imagine your ERP is about 400GB
worth of active data and you have to generate backup set that big on
daly basis? I don't even know yet what kind of bandwidth I'll have to
our DR location. Assuming I get backupset generated in 4-5 hours, how
many hours will be required to send it off?  Also what happens if then
the managment decides they want a few more machine to join the first
one at DR location? This solution sound like a nice idea TSM-wise, but
imho it's not very scalable otherwise. As it looks to me the best
approach is to backup locally, dedupe, send it off deduped.


> they want daily fulls of, and make a backupset of that nodegroup every
> day.  Give the backupset a 7 day retention, and keep track of the
> volumes that are in the list of backupset volumes from one day that
> disappear the next (simple to script).  That same script can note tapes
> that show up in the list of backupset volumes that weren't there the day
> before, and check them out of the library and throw your operations team
> an email listing every tape to be sent offsite and to be recalled.  I
> find that I can generate file-class backupsets(with TOC) at about 27MB/S
> - 8.5 hours to do an 814GB node, single-threaded.
>