ADSM-L

Re: [ADSM-L] Looooooooooong distance backups

2008-03-19 10:39:55
Subject: Re: [ADSM-L] Looooooooooong distance backups
From: Thomas Denier <Thomas.Denier AT JEFFERSONHOSPITAL DOT ORG>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 19 Mar 2008 10:36:21 -0400
-----Zoltan Forray wrote: -----

>We at VCU (Richmond, VA) have a "campus" at Doha, Qatar
>(approximate distance is 7K miles).
>
>We are discussing the viability/possibility of having TSM clients in
>Qatar backing up to our TSM servers, here in Richmond!

You may need an unusually large amount of buffer space for TCP. The
buffer space requirements for a TCP connection scale with the product
of bandwidth and round trip time.

If you use the central scheduler, you will have to allow for the time
zone difference, and for the changes in time zone difference when
Virginia transistions to or from daylight saving time and Qatar
doesn't.

You will need to assess the risk of missing backups because of
connectivity problems. In the last few years there have been
several incidents in which undersea cables serving Asia were
damaged and whole countries had limited Internet bandwidth or
no connectivity at all for periods measured in days.