Actually we were hoping to limit ourselves to 2 server, but our performance
evals seem to suggest this is impossible. We currently see 500-1000Kb/s on
our eval machine going to a disk storage pool. Unless we can get performance
in the 2000-2500Kb/s range, we will need more than 2 servers. What we are
trying to figure out is where is the bottleneck and how can we eliminate it?
The only bottleneck we can?t eliminate in our test environemtn is the
database, and we are trying to guage the impact of going from one disk
mirrored to another to a system of 6 stripped disks mirrored to another set
of 6. This is all with a Model 39 RS/6000 machine with a FDDI interface
driving ADSM.

Paul Shields
pshlds AT bnr DOT ca
Bell Northern Research


>>It certainly sounds like you are going to run into some very significant
>difficulties if you are going to run on one RS/6000 server with this many
>files to manage.  ADSM does an absolutely superb job of moving data around
>(terabytes are not a problem) but you have to be aware that it is a
file-level
>backup system (as opposed to a filesystem-level system) from the standpoint
>of catalog management (i.e. UNIX dump has no real online catalog to
interactive
>y
>query, you typically read it from the tape) and full restores of filesystems
>with large numbers of files (the filesystem size is totally immaterial
because
>ADSM does not have problems moving bulk data), typically 100,000-ish or more
>can get a bit slow.
>
>E-Mail me at mitch AT cellnet DOT com if you would like to correspond regarding
this
>matter.  At my current company we run a very small ADSM system.
>
>> I am looking for people who have adsm configured in an environment
similiar
>> to ours. We are currently looking at backing up about 1.4T of data spread
>> across about 200 machines.
>>
>> The important part is the following. Our average file size is in the 20 -
>> 40Kb range which under our current evaluation and test environment seems
to
>> be stressing the database on the RS/6000-based server.
>>
>> Is there anyone out there with similiar average filesizes, backing up at
>> least several Gigs of data that would be willing to iscuss your
experiences
>> in performance and configuring the servers for optimal performance.
>>
>> Paul Shields
>>
>
>___________________________________________________________________
>Mitch Sako                            Phone:     (415) 508-6761
>Cellnet Data Systems                  FAX:       (415) 508-6700
>125 Shoreway Road                     Pager:     (408) 989-3365
>San Carlos, CA 94070                  email:     mitch AT cellnet DOT com
>                                      personal:  msako AT netcom DOT com
>