Re: Tuning tips?

1997-12-10 12:48:25
Subject: Re: Tuning tips?
From: "McGrew, Perry" <pmcgrew AT AGWAY DOT COM>
Date: Wed, 10 Dec 1997 12:48:25 -0500
Thanks for feedback...I'm fortunate that I do not have to worry about bandwith, 
as the ATM network is for ADSM use.  I will play with compression but can you 
tell me what the CPU penalty for using ADSM compression?
Thanks -- Perry

Lee Russon wrote:

> Perry,
> Consider using ADSM compression on your AIX clients as this can improve 
> network throughput. We tested RS/6000 AIX clients running with compression 
> and without and found that the backup of data took 3 times as long without 
> compression. If network bandwidth is not a problem then leave compression 
> off, but remember that more data will be processed by the server before the 
> data arrives on tape.
> We transfer all client backup data to a primary disk pool overnight and copy 
> the disk pool data to tape after all clients have been backed up. The tapes 
> are then sent to off-site storage. During the day we migrate data from the 
> disk pool to on-site tape to free up space for the next nights run. This 
> method seems to work quite well as client machines do not have to wait for 
> tapes to be mounted and the server has less data to process.
> The options you use on the clients are very similar to our own, but you may 
> find that increasing the TXNBytelimit may improve performance (it all depends 
> on how fast your HP/IBM machines are)
> Regards,
> Lee Russon
> Midlands Electricity plc
>  ----------
> From: McGrew, Perry
> To: adsm-l AT vm.marist DOT edu
> Subject: Tuning tips?
> Date: 10 December 1997 13:59
> We've just installed ADSM/MVS 3.1 on our TCP/IP 3.2 Ethernet network
> over ATM (LANE) backbone.  We have the lastest ADSM 3.x client code on
> our HP-UX 10.2 & IBM AIX 4.3 servers.
> In the dsmsched.log I am seeing:
> Network data transfer rate:        1,772.97 KB/sec
> Aggregate data transfer rate:      1,468.25 KB/sec
> We do not have ADSM compression turned on as we are using hardware
> compression on our 3494/3590 MagStar tape drives.
> Our TCPIP/MVS 3.2, the  LARGEDATABUFFERPOOLSIZE is set to 32768.
> In the HP / AIX Clients' the dsm.sys parameters are:
>    TCPWindowsize      64
>    TCPBuffsize             32
>    TXNBytelimit       2048
> Any help in identifying critical tuning points will be appreciated!
> Thanks,
> Perry McGrew
> Agway Inc.
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