David,

Our policy has been to use J tapes only for collocated pools, K for
non-collocated.  This maximizes the larger tapes and reduces the number
of offsite tapes we have to manage.  The downside to the bigger tapes,
especially with copy pools, is that reclaiming them becomes very
difficult as the number of nodes increases (reclaiming 1 copy pool tape
could mean having to mount as many primary tapes as you have nodes).

Steve Schaub
Systems Engineer, Operations & Storage
Haworth, Inc
616-393-1457 (desk)
616-886-8821 (cell)
Steve.Schaub AT Haworth DOT com 

-----Original Message-----
From: David E Ehresman [mailto:deehre01 AT LOUISVILLE DOT EDU] 
Sent: Monday, February 23, 2004 10:30 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: J vs K 3590 Tapes


We are backing up to 3590 tapes.  We currently use K (extended length)
tapes for onsite tape storage pool and J (standard length) tapes for
offsite copy storage pool.

We will soon start replacing some of our older J tapes and are trying to
decide whether to replace them with Js or Ks.  Has anyone weighed the
pros and cons of using Js vs Ks for offsite tapes.  Which did you decide
on and why?

David Ehresman
University of Louisville