We've seen a lot of problems with ports 'flapping', especially when all
sides are auto configured. Flapping may be an unofficial term although HP
has been using it pretty freely to describe what happens when their switch
ports go through mode arbitration after the initial connection arbitration.
This is NOT supposed to happen, but the two devices can't always agree on
the mode - full or half, 10 or 100. It doesn't show up on the idiot lights,
and happens too quickly to view on management software - but if you lock
both sides down the problem (almost always) goes away. FWIW, a 10/100 hub
has a 2 port switch inside and each port can connect to the 10 or 100 side.
I haven't seen the problem directly with one of these hubs, but it's
theoretically possible. To be sure an old style hub on both the backup
machine and source machine will rule this out.

        -----Original Message-----
        From:   Steve Yuroff [SMTP:[EMAIL PROTECTED]]
        Sent:   Wednesday, February 14, 2001 6:03 AM
        To:     [EMAIL PROTECTED]
        Subject:        Re: 0.8 MB/min?

        Randy,

        What is the difference between a 100 hub and 10/100 autosensing
switch that you predict will fix this problem? Since my original post, I
have had the machine on a 10/100 hub uplinked to the main switches, and it
behaved the same.  (Yes, I realize this is in your NOT section, it's just a
mention.)

        Thanks,
        Steve.
         
        -- 
        Steve Yuroff
        Network and System Administrator
        The Hiebing Group
        Madison, WI.

        On Tuesday, February 13, 2001 1:24 PM, Grein, Randy <[EMAIL PROTECTED]>
wrote:
        >Steve,
        >There's a strong possibility that you're suffering from one or more
of the
        >dreaded 'stupid switch, stupid plug&play' syndrome. If you can, put
it on a
        >fast ethernet hub (NOT a 10/100 hub!) and test. If that works, fix
the
        >switch port to 100 half duplex.
        >
        >       -----Original Message-----
        >       From:   Steve Yuroff [SMTP:[EMAIL PROTECTED]]
        >       Sent:   Monday, February 12, 2001 3:42 PM
        >       To:     [EMAIL PROTECTED]; [EMAIL PROTECTED]
        >       Subject:        Re: 0.8 MB/min?
        >
        >       I was plesantly surprised when someone from Dantz Tech
Support
        >(SHAME on me for not noting who it was!) phoned me to discuss this
post.
        >Let me pubicly thank Dantz for taking the step to phone me to help.
        >Unfortunately, we did not pinpoint where the problem lies, but
there are
        >some updates to the story, which I'll share in hopes that it will
someday
        >help someone else (cuz we all search the archives, right?):
        >
        >       This morning I started an immediate duplicate of the source
machine
        >(B&W G3) to my archive tape set.  It started at a typical 65MB/sec,
but
        >again the speed fell through the day, looking like this:
        >
        >       11:00A - 65MB/min
        >       1:37P  - 15.4MB/min
        >       3:16P  - 10.7MB/min
        >       4:52P  - 8.1MB/min
        >       5:30P  - 7.4MB/min- which is as I type right now.
        >
        >       I have screenshots that show the speed and monitor window
from
        >IPNetMonitor, in case they may be of value.
        >
        >       Prior to the backup, I ran DiskWarrior 2.0 on the client,
which did
        >find problems in the Volume Information of the only disk.  Although
DW
        >reported them fixed, my speed declines persist.
        >
        >       To address your questions and points, and give more info:
        >       The original post came on a Saturday morning.  Over Friday
night, my
        >network traffic was at it's lowest possible, so I doubt network
congestion
        >is the problem.
        >       My local operations are at the speed I expect.  The backup
server
        >can copy to from an ASIP server at about 7MB/sec.
        >       Source and destination for the duplicate were both Retro
clients.
        >There would be no communication problems with a tape drive in the
original
        >post.
        >       Network is 100B switched.
        >       Backup server has 224MB of RAM, 15MB set for Retro
preferred.
        >       Between the original duplicate and the above Immediate
Backup, I ran
        >a normal incremental backup on my LAN.  Copied 7 gigs from an ASIP
server at
        >71MB/sec average. Entire copy here is just over 3 gigs.





        --
        ----------------------------------------------------------
        To subscribe:    [EMAIL PROTECTED]
        To unsubscribe:  [EMAIL PROTECTED]
        Archives:        <http://list.working-dogs.com/lists/retro-talk/>
        Search:  <http://www.mail-archive.com/retro-talk%40latchkey.com/>

        For urgent issues, please contact Dantz technical support directly
at
        [EMAIL PROTECTED] or 925.253.3050.


--
----------------------------------------------------------
To subscribe:    [EMAIL PROTECTED]
To unsubscribe:  [EMAIL PROTECTED]
Archives:        <http://list.working-dogs.com/lists/retro-talk/>
Search:  <http://www.mail-archive.com/retro-talk%40latchkey.com/>

For urgent issues, please contact Dantz technical support directly at
[EMAIL PROTECTED] or 925.253.3050.

Reply via email to