[Veritas-bu] Multiplexing
2002-03-01 18:43:11
Thanks Scott. I am seeing these performance stats during full backups,
which I think is fairly dismal. My server is an E250 with 2 X 400MHz
with 2gb RAM, Sun gigE card. The scsi controller is a Sun dual channel
HVD card with 2 drives on one channel and the 3rd on the second
channel. By all rights it should not be a problem.
I have noticed that my memory drops to 32mb avail after being up for
about a week. It seems to be the java process for VxVM taking *huge*
memory alloc's. But I do not seem to be memory constrained, rather io.
And looking at the drives I can see it plainly. What I haven't figured
out yet is why. The Novell servers are fairly high end PC's with gig
cards and at least 1gb ram. From a user stand point they perform
nicely, simply from a backup standpoint they don't.
Anyway, I'll change the mpx for the offsite schedule and see how that
works. I haven't changed the defaults but retention level is all the
same.
Thanks again.
~JK
scott.kendall AT abbott DOT com wrote:
>
> you can leave stu at 4 but it won't matter as long as it's greater than 3 in
> your case. clients/schedules don't have to be in the same class to mpx to the
> same tape drive. change mpx for schedules for each of your 5 classes to 3. 3
> will go to one drive and the remaining 2 will go to the other.
>
> mpx'ing 3 to one drive and 2 to the other is what you asked for. this may not
> be the best for both fulls and incrementals. you may be able to stream the
> drive with a smaller mpx on fulls... make sure your media server nic isn't the
> bottleneck here.
>
> also, keep in mind that they won't mpx if they're different retention levels
> (unless you've changed default)
>
> - Scott
>
>
> "Jeff Kennedy"
> <jlkennedy AT amcc DOT com> To: NBU
> List <veritas-bu AT mailman.eng.auburn DOT edu>
> Sent by: cc:
> veritas-bu-admin AT mailman DOT eng. Subject:
> [Veritas-bu] Multiplexing
> auburn.edu
>
>
> 03/01/2002 04:19 PM
>
>
>
> I have created a seperate class for each of my 5 Netware servers. Maybe
> that's not the best practice but that's how it is right now. I want to
> multiplex 3 of these to a single drive and 2 to another. The storage
> unit is set to max 4 multiplex but the schedule is set to 1. I
> understand that both need to be adjusted, but it reads to me that the
> multiplex number by schedule assumes mutiple clients per class. So what
> happens to me with only 1 client per class? Am I screwed?
>
> I am looking at multiplexing because on a Sun E250 I am finding that one
> cpu is at 95%+ idle while the second is 0% idle, with 90% cpu being used
> in a wait state. I watch my drives with iostat and I'm seeing several
> hundred k to 5mb/sec thruput per drive (dlt7k). 5mb/sec would be fine
> but it shoeshines between the 2 extremes, so I want to just blast a
> drive as hard as I can.
>
> As always, suggestions for improvement in my methods are welcome.
>
> Thanks.
> --
> =====================
> Jeff Kennedy
> Unix Administrator
> AMCC
> jlkennedy AT amcc DOT com
> _______________________________________________
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--
=====================
Jeff Kennedy
Unix Administrator
AMCC
jlkennedy AT amcc DOT com
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