Hello Ben,

the network does not have to be the bottleneck.
You could run client compression, and shift the bottleneck to your oracle
servers, where
performance would then be limited by either the efficiency of the
compression algorithm and its
CPU overhead, or the speed at which you can extract data from the disk.
Oracle's EBU allows multithreading to maximise disk throughput.
ADSM privides the client compression (a little inefficient tho .. null block
compression would be better).

Generally, however, as your data increases, and backup windows decrease, the
subsequent expense
in infrastructure to meet requirements also increases. ATM would be nicer
than 100BT. A reasonably sized
ADSM disk pool would also help.

Good luck
Andrew Swift
*andrew.swift AT colesmyer.com DOT au
*61 (3) 9483 7629


> -----Original Message-----
> From: Ben Kokenge [SMTP:ben AT EDMS DOT NET]
> Sent: Saturday, October 31, 1998 4:10 AM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      DB storage/performance question ADSM or Legato?
>
> We are looking at a situations here and I would like some advice.
> We have 2 Oracle servers of 200GB/each and 2 SyBase servers
> of about 200GB/each all running on HP's.  We need to run full
> backups nightly (full due to restore performance issues) of each
> server.  There are also some 500 desktops to backup incrementally
> Now here are the issues.  If we design an ADSM library system
> for this setup, we would need something that could back up like
> almost a Terra-byte a night (12 hours/night).  This is where ADSM
> breaks down.  Is it possible to move that much data through a
> network to single ADSM library per night?  If we have one big library,
> say an R50 RS/6000 with 3494 library with 4 x 3590 drives, it might
> be able to handle the data volumes, but can you get all the data there
> in 12 hours?  If we run 2 100mbps fast ethernet line to the R50
> we could, in theory, move 650GB in 12 hours. Calculated:
>
> (100Mbits/s) x (2 lines) x (60% efficiency of ethernet) / (8Mbits/MB) =
> 15MB/sec
>
> which translates to 650MB/12hours.  Sure I could add another ethernet
> card, but I don't think the ADSM server can update it's own database
> and backup data faster than 15MB/sec.  I used shared memory and
> can only backup off SSA at 4MB/sec under ideal conditions.  Multi-thread
> that and triple it, but the ADSM database files are running 100% busy.
>
> So, this is where Legato comes in.  Legato works well at backing-up
> to tape drives attached to local machines.  I could use Legato to
> backup the Oracle and SyBase servers, then use ADSM for all the
> desktops (incremental backup is ADSM's forte').  I have pondered the
> idea of having each database server run its own ADSM server and backup
> to local tape drives; that would probably work, but that is somewhat
> pricey.  I REALLY don't want to use Legato.
>
> Get to the point Ben.  OK.  What I would like to know, and I know there
> has to be others out there with these kind of problems, is how does one
> goes about backing up several large database servers?  Someone will
> probably throw out the "connect agent" and "backtrack" words, but again
> we have restore performance issues, so only full database backups are
> allowed.
>
> I humbly await responses.  (well maybe not the "you idiot" ones...)
>
> -Ben