Conference decwet::networker

You haven't specified what version or OS the networker
server is, that would help some.

It is not possible to multiplex a backup of one object 
into multiple output devices as you describe it.

As a first guess, I would configure all 4 clients into
1 savegroup.  Configure the server for 6 save sessions
per device (S/D) and parallelism of (S/D)*(# of devices).
In "details" or "-x" view of the client setup, make certain
that client parallelism is at least 2. This configuration
should give you close to optimal throughput.

3.3 GB/hr is not very good performance.  Are these systmes
on FDDI or Ethernet?  

Mark

    In addition to looking at the kind of network interfaces, look at the
    the network path between the client and the NetWorker server.  How many
    routers are handling the data?  Are the clients and NetWorker server in
    different subnets?  If so, and the clients and servers are on the same
    LAN, consider adding multiple addresses to the server's network
    adapter, one for each site subnet you have backup clients in.  That
    way, the data won't have to be routed between the client and the
    server.  You'll need to use the Server Network Interface field for each
    client.
    
    tl

	Thank you very much for your fast answers.

	I�ll try to explain better:

	The customer does not have networker yet. The customer is making backups now with 
Seagate Backup Exec v6.0.
	The four servers are linked with other ten smaller servers in a switched FDDI with a 
gigaswitch, with a transmission rate about 100Mb/s to each server.

	The performance is poor, of course. We are trying to increase the performance with 
NSR 4.3 for Windows NT and also making simultaneous backups to a several tapes as I explained 
in .0.

	We are making tests at our office with an alphaserver 2000 and two tapes locally 
attached to two SCSI cards, and with NSR 4.3 for WNT/ALPHA. The transmission rate tha we are 
obtainning is only few better (0.9MB/s)

	Best regards
	Alfonso Vara


	

	

With a Sable or Lynx NetWorker NT server, FDDI, and 3 TZ88/TZ89 drives, 
you could expect upwards of 5 to 6 MB/s (~18 GB/h), at least those
are the kinds of numbers I've seen in our lab with the NT product.
Your milage may vary, especially with less capable equipment.

Mark

	reply to .4

	How do you obtain that great values ?

	My test equipment is

	An Alphaserver 200 /233 with 128 MB of RAM
		Windows NT 3.51 (without any SP)
		Networker 4.3 for windows NT
		Two tz87 attached to different scsi card each one.
		Compressed backup
	The ratio that I�ve obtained is about 1 Mb/s more or less.

	Where is my problem ?

	How can I reach the ideal conditions of 2 to 2.5 MB/s of transfer 
ratio of the TZ87 ?

	Thanks in advance an best regards.

	Alfonso Vara
	OMS - SPAIN
	Madrid

You can look at the configuration I used at

http://wenitrains.zso.dec.com/devplan42a.htm

search for the string "A performance baseline",
it's near the end of the document.

If you have more questions, address them to me
via email.  [email protected]

Regards/Mark

Oh, by the way, you should really install SP5 on
your NT 3.51 system, we don't support "SP0"

Mark

Oh, turns out the web page I pointed you to did not have the
configuration I was thinking of.  Here's a configuration
that's closer to what I had in mind. The 2100 used for this
test is now a bit of an outdated system (uses slow 200 MHz 
processors).


Server:  AlphaServer 2100 4/200.  This is a 2 CPU machine with
	256 MB memory. NT 3.51. Output to a TL812 with 4 TZ88 drives.
	2 KZPSA SCSI controllers, 2 drives per controller.

Client base:  3 Digital UNIX clients with direct FDDI
	connection, plus the server itself.

Test:  Only 2 TZ88's were used in the test.  The UNIX clients
	saved a standardized large saveset.  The server saved
	whatever it had on its disks.  Parallelism 12, 
	AD 2, Sessions per device 6.

	Best throughput to tape observed was 4.6 to 4.8 MB/s, which
	is 15-17 GB/hr.  

	This is essentially both drives running
	in streaming mode with highly compressable data.  You can't
	get much better than that.  CPU utilization at these
	sustained peaks was 85-90% on both processors.  So there
	is a little more CPU performance available in the processor
	but probably not enough to add another tape drive without
	degrading streaming performance on the other two (and thus
	overall throughput).

One final note:  the current development project for the 
Digital UNIX server is advancing the technology quite a bit
in the area of performance.  This technology will find its way
into the NT product in the future.  To give you a ballpark 
figure, the goal for the DU project is to achieve 250 GB/hr
with 20% CPU utilization ON A SPECIFIC BENCHMARK CONFIGURATION
(i.e., a BIG BUCKS configuration).

If you are using compression, you won't write more than about 
1.25 MB/s to a single TZ87.

Also, compression uses CPU.  Maybe the client can't read and 
compress the data fast enough.

re: .5, is your test system doing local or network backup?

Wes