Poor performance with 6385 13GB 1/4" Tape Drive

[Neil Palmer <npalmer@xxxxxxxxxxx>]

FYI:

If you have a 6385 13GB 1/4" tape drive you should apply the following
PTF's:
  Release 370   : MF16958 available 97/11/07 (1000 )      (1000 = not
yet on a cum package)
  Release 410   : MF17450 available 97/11/10 (1000 )
  Release 414   : MF17451 available 97/11/10 (1000 )
  Release 420   : PTF not available yet

This will update the tape drive's microcode to fix a severe performance
problem (see my example below).

Also, if you use INZTAP with CLEAR(*YES) on a 6379, 6380, 6381 or 6385
you should also apply the following fix:
Release 410   : MF17800 available 97/12/12 (1000 )
Release 414   : MF17801 available 97/12/12 (1000 )
Release 420   : PTF not available yet



I just recently installed my new 9406-S10 (2118) with both a 6385 13GB
1/4" tape drive 
(1.5M/Sec transfer rate), and a 7208-222 7GB 8mm tape drive (500K/sec
transfer rate).
I was certainly surprised to find the following:

Backup task         6385 1/4"     7208-222 8mm     % SLOWER on 6385     
SAVSYS                 30:19          25:12              20.3%          
SAVLIB *NONSYS       3:43:48        3:01:06              23.6%          
SAVDLO *ALL             9:39           6:55              39.5%          
SAV '/*'               10:17           9:53               4.0%          
                                                                        
TOTAL OF ABOVE       4:34:03        3:43:06              22.8%          
                                                                        
TOTAL # BYTES WRITTEN       6385    8,795,568,000                       
(for entire system save)    7208    8,717,827,000


IBM's reply to the performance complaint:

There has been a performance issue raised against the 6385 drives.

PTF MF17450 has been created to resolve this. I found another   
customer whose *NONSYS saves dropped from 12 hours to 6.5 hours after   
applying this PTF on a 6385 so I hope your results are similar and      
your faith in the drive is returned.                                    
.                                                                       
Also, please apply MF17800 as it resolves another problem with INZTAP   
on this drive.


... Neil Palmer                                     AS/400~~~~~      
... NxTrend Technology - Canada     ____________          ___  ~     
... Thornhill, Ontario,  Canada     |OOOOOOOOOO| ________  o|__||=   
... Phone: (905) 731-9000  x238     |__________|_|______|_|______)   
... Cell.: (416) 565-1682  x238      oo      oo   oo  oo   OOOo=o\   
... Fax:   (905) 731-9202         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
... mailto:NPalmer@NxTrend.com          http://www.NxTrend.com

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