Make sure that you understand "Device - Target Sessions" means that it's the
number of streams that a device will take BEFORE legato will start sending
streams to the next device. It's not a maximum number of streams. For
instance, the default I think is usually set to 4 for most devices. This
means that the tape drive will accept 4 streams of data. When the 5th
stream of data is ready, it will be sent to the NEXT tape drive. Once the
next drive reaches 4 streams, it will move to the next drive, and so on.
Once all drives have 4 streams, legato will go back to the first tape drive
(which might still have 4 streams) start sending the next stream of data to
the first drive.
Server parallelism is the maximum number of streams the server can process
at one time.
Client parallelism is the maximum number of streams that a particular client
can start at one time. For example, if you have a windows box with 4 file
systems (C:, D:, E:, and F:) which are listed as the Save targets, and if
you have the client parallelism set to 2, then when the backup starts, it
will start 2 of the files systems.
With the settings you've described below, you will only use 1 tape drive
because your target sessions is higher than your Server parallelism, and
you'll never use all of your server parallelism sessions because your client
parallelism is set to 6.
What you want to do is try to maximize the amount of data being written to
each device.
Monitoring the usage of a tape drive is not straight forward, but Thierry
Faidherbe's Networker Reporter utility really comes in handy there. You can
use it to see how changing settings affects your tape drive
usage/throughput.
Hope this helps.
David
-----Original Message-----
From: Legato NetWorker discussion [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU]
On
Behalf Of Andrew Bridgeman
Sent: Tuesday, May 24, 2005 10:17 AM
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Subject: [Networker] Parallelism/target sessions and block size settings
Linked to "Speed of Networker backups to disk"
I read all of the replies with regards the speed of my backups to disk and
it seems there are two things to look at:
1). The Parallelism and target sessions need looking at.
2). Volume Block sizes under devices tab needs changing to more than 32K(
if possible)
My Current settings are: Server Parallelism 8
Device - Target Sessions 10
Client Parallelism - 6
I am backing up 7 clients every night currently, it used to be 10 hence the
settings above are a bit high. Could i please have some advice on what
settings i should have now and also if i can change the Volume Block sizes
to a higher value when i am running Network edition of networker.
Any help is much appreciated
Regards
Andrew Bridgeman
--
Note: To sign off this list, send a "signoff networker" command via email
to listserv AT listserv.temple DOT edu or visit the list's Web site at
http://listserv.temple.edu/archives/networker.html where you can
also view and post messages to the list. Questions regarding this list
should be sent to stan AT temple DOT edu
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
--
Note: To sign off this list, send a "signoff networker" command via email
to listserv AT listserv.temple DOT edu or visit the list's Web site at
http://listserv.temple.edu/archives/networker.html where you can
also view and post messages to the list. Questions regarding this list
should be sent to stan AT temple DOT edu
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
|
