Networker

Re: [Networker] Performace isssues with LTO 2 Ultrium and unable to write to all tapes at same time

2004-01-11 12:46:01
Subject: Re: [Networker] Performace isssues with LTO 2 Ultrium and unable to write to all tapes at same time
From: Paul Galjan <pgaljan AT YAHOO DOT COM>
To: NETWORKER AT LISTMAIL.TEMPLE DOT EDU
Date: Sun, 11 Jan 2004 12:45:57 -0500
I don't know if you're going to be able to get the advertised 180 MB/s  for
all six drives.  But the place to start would be to see if you can get
anywhere close to that rate backing stuff up without going over the network.
See if you can write two data streams at 30 MB/s each, step it up from
there.  See when it breaks.

Another area to check would be to make sure that you are effectively load
balancing over both the NICs.

Yet another suspect would be the Networker database.  You've got a partition
with 3 MB files, so each drive should be backing up 10 records per second.
That 60 inodes per second, each updating the database.  I'm no Networker
database expert, so I can't say for sure if the software can handle that
(perhaps someone on this list can), but you can definitely tell if it's a
hardware bottleneck.

How is the SCSI bus configured (how many channels are the drives spread
over?).

--paul


----- Original Message -----
From: "Alex Theodore" <alex AT FUZZYCHEESE DOT COM>
To: <NETWORKER AT LISTMAIL.TEMPLE DOT EDU>
Sent: Sunday, January 11, 2004 11:19 AM
Subject: [Networker] Performace isssues with LTO 2 Ultrium and unable to
write to all tapes at same time


> I am only getting about 3-6 megabytes/s when backing up to LTO 2 tape
drives.  I would expect that I should get somewhere near the advertised
value, but I am not.  Here are the details.
>
> - Legato Network 6.7.1
> - Solaris 8 (latest patches)
> - Sun L700 with 6 HP LTO 2 tape drives
> - Backup Server is a Sun Fire V880
> - Backup Client is Sun Enterprise 4500
> - Network pipe for backups is a dedicated, directly connected (no switch),
dual gigabit ethernet, which is trunked (glued together into 1 virtual pipe)
>
>
> The data on the client which is being backed up are images (photos) which
are a few megabytes in size.  I decided to split up the save sets into 6
different client configurations with the parallelism set to 6 so that all 6
tape drives would be used at the same time during backups but this isn't
happening either.. I can only seem to write to a few tape drives at once..
>
> Any ideas would be greatly appreciated.
>
> TIA,
>
>   Alex
>
> --
> Alex Theodore
> alex AT fuzzycheese DOT com
> Boca Raton, FL  USA
>
> --
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