Replace old tapes when you upgrade your drive

[neilp@xxxxxxxxxxx]

FYI

Thought this would be interesting to those who may be tempted to save a 
few dollars when upgrading a tape drive by cintinuiing to use old tapes. 
This customer had a 6385 (MLR1-16GB and MLR1-13GB tapes) and went ot a new 
system with a 6384 (SLR60).  The first few nights, until they received the 
new tapes, they used the old MLR1-13GB tapes (26GB with compression), then 
switched to the new SLR30-60GB tapes.

Here's a comparison of a SAVALL backup (Save Entire System) run on two 
consecutive nights on their new 270-2432.
The only difference between the two nights is that the first backup was 
run on their old 13/26GB tapes (QIC5010 or MLR1 format) and the second 
night was run on new 30/60GB tapes (SLR60 fornat).

They have a 6384 (30/60GB QIC SLR60 format) tape drive.

Using QIC5010 format on MLR1-13GB or MLR1-16GB tapes this drive is rated 
at 1.5M/sec. 
It uses a block length of 32,760.

Using SLR60 format on SLR60-30GB tapes this drive is rated at 4.0M/sec. 
It uses a block length of 262,144 (except first part of SAVSYS is 32,760).

Backup Task                     QIC5010 format          SLR60 format
SAVSYS                  14 min 48 sec            8 mn 40 sec
SAVLIB QGPL/QUSRSYS     37 sec                  23 sec
SAVLIB *NONSYS          50 min 11 sec           19 min 04 sec
SAVDLO *ALL                     13 sec                  11 sec
SAV /*                          19 min 11 sec            5 min 28 sec

Bytes written                   16.877GB                16.912GB

System is a 270-2432 with batch CPW 1070.
5 x #6718  17.548GB disks (RAID-5)
System ASP 70.19GB - 27.46% full.


Neil Palmer      DPS Data Processing Services Canada Ltd.
Cambridge, Ontario, Canada.                 OS/400~~~~~
Phone:(519) 653-1027        ____________          ___  ~
Cell.:(416) 565-1682        |OOOOOOOOOO| ________  o|__||= 
Pager:(416) 501-1682        |__________|_|______|_|______) 
mailto:NeilP@DPSlink.com     oo      oo   oo  oo   OOOo=o\
http://www.DPSlink.com       IBM iSeries   The Ultimate eServer