Eric,

if you set-up an EtherChannel on both sides (!) it is like connecting
through 400 Mb/s interface (virtual one which distributes load on real ones
ent0, ent1, ...). This is done at interface (OSI Level 2) and has to be
transparent to your sessions. Anyway you must have 4 adapters on both ends
and good switch or you will get a bottleneck limiting your speed.
Maybe you can tweak TSM and backup to more than one server but the restore
later will be a nightmare.
Install Etherchannels on both ends, test its throughput with ftp and that's
all. If you are not satisfied with the speed go to Gigabit Ethernet.
One session with tuned TCPwindowsize must perform similarly to four and to
be limited only by TCP/IP throughput. But more sessions may help if you
backup direct to tape to use many drives simultaneously.

Zlatko Krastev
IT Consultant





Eric Winters <ewinters AT AU1.IBM DOT COM> on 23.09.2001 08:03:51
Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
To:     ADSM-L AT VM.MARIST DOT EDU
cc:

Subject:        Re: Etherchannel and EBU backups.

I've had some feedback re my attached note explaining that whilst it will
work, all four sessions would operate through a single interface on the
client and a single interface at the TSM server end, not improving my
throughput a jot.

Forgetting Etherchannel for a moment, is there any way that an EBU/TDP for
Oracle can direct individual parallel sessions to different TSM servers? I
don't see how - as I understand it the entire database instance is sent
with optionally multiple parallel sessions to a single TSM server. Of
course I don't really want to backup to separate servers, but I do want to
backup to 4 different IP addresses. Can I do this?

Regards,

Eric Winters
I


I'm interested in determining if etherchannel and EBU/TDP for Oracle, might
be effective in reducing backup times.

Client system: AIX 4.3.3, uses Oracle 7 and backs up using EBU via TDP for
Oracle 2.1
Server system: AIX 4.3.3 and TSM Server 3.7

Network interfaces today are 100 MB ethernet, a single adapter in each
system.

Proposal is to speed up backups by using 4 ethernet adapters in both the
client and the server and use Etherchannel. 4 parallel sessions would be
set in the EBU script. A much larger database will be implemented shortly
and etherchannel looks attractive, providing TDP for Oracle will use 4
concurrent sessions, which I think it should.

Can anyone confirm that the above should be a workable solution? Is anyone
doing this?


Thanks people,

Eric Winters