ADSM-L

Re: 3590: tape-to-tape transfer rates

1997-08-22 03:37:53
Subject: Re: 3590: tape-to-tape transfer rates
From: Henk ten Have <hthta AT SARA DOT NL>
Date: Fri, 22 Aug 1997 09:37:53 +0200
Tom wrote:

>We are using 3590 drives in a 3494 library. Each drive is on
>its own SCSI bus. Our ADSM server is a wide node of an SP2, with
>256MB of RAM. The database size is 22GB.

 We are using 3590 drives in a 3494 library. Each drive is on
 its own SCSI bus. Our ADSM server is a wide node of an SP2, with
 512MB of RAM. The database size is 9GB.

>I'm curious to know why we might be seeing such a low transfer
>rate. The 3590s are supposed to be rated at 9MB/s, so during
>regular sustained operation I'd hope to see at *least* 3-4 MB/s.

 Just an example from this morning:

08/22/97   07:30:01  ANR2750I Starting scheduled command BACKUP_COPY ( back stg
                      3494pool 3494pool.cp ).
08/22/97   07:30:02  ANR1210I Backup of primary storage pool 3494POOL to copy
                      storage pool 3494POOL.CP started as process 124.
08/22/97   08:48:36  ANR1212I Backup process 124 ended for storage pool
                      3494POOL.
08/22/97   08:48:36  ANR1214I Backup of primary storage pool 3494POOL to copy
                      storage pool 3494POOL.CP has ended.  Files Backed Up:
                      20713, Bytes Backed Up: 23869240782, Unreadable Files: 0,
                      Unreadable Bytes: 0.

So, that means a rate of 4.9 MB/s (23GB/78/60).
This is what a see every day, approximately 5 MB/s.

>I just realized that our dsmserv.opt has the values of
>MOVEBATCHSIZE and MOVESIZETHRESH switched around (MoveBatchSize
>is set to 500, and MoveSizeThresh is set to 256, while it should
>be the other way around). Would having an invalid value for
>MoveBatchSize (500) set the value to the default (40) or to the
>max (256)?

 If you do a Q OPTION you can see (all) the settings, in our case:

 MoveBatchSize     1000
 MoveSizeThresh    500


(running ADSM V2.1.0.13 on a SP2 (AIX 4.1.4.0) using 3494 with 4 3590 units,
 backup/archive client's 2.1.0.6 on AIX 3.2, AIX 4.1.4, SunOs, Solaris,
 IRIX, Win95, WinNT, HSM client's 2.1.0.6 on AIX 4.1.4.0)

Regards,

Henk ten Have                   SARA, Academic Computing Services Amsterdam
Systems Programmer              Kruislaan 415
E-mail: hthta AT sara DOT nl           1098 SJ Amsterdam
Phone : +31205923000            The Netherlands
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