I'm not familiar with what type of disks/controllers your array uses, but if 
possible, use newer SATA2 equipment.  It has support for native command 
queuing, which helps random access a lot.  It's exactly why scsi disks are good 
for it, although scsi firmware tends to have deeper queues (which is why it's 
still better than even sata2).
 
 
Troy Frank
Network Services
University of Wisconsin Medical Foundation
608.829.5384

>>> mark.stapleton AT BERBEE DOT COM 8/17/2005 8:40:20 AM >>>
You can use SATA disk in a random-access pool, but you're going to get 
performance hits because of the very nature of the disk.

--
Mark Stapleton (stapleton AT berbee DOT com )
Office 262.521.5627

________________________________

From: ADSM: Dist Stor Manager on behalf of Joni Moyer
Sent: Wed 8/17/2005 08:23
To: ADSM-L AT VM.MARIST DOT EDU 
Subject: Re: AW: [ADSM-L] Migration Speed Has Plummeted



Hi Mark,

If it's strength is within sequential access, is there anything that I can
do with the SATA disk at this point in time? Are there parameter changes
or different configuration usage that I can do in order to still utilize
the SATA disk as the disk storage pool? Or am I out of luck? Thanks
again!

********************************
Joni Moyer
Highmark
Storage Systems
Work:(717)302-6603
Fax:(717)302-5974
joni.moyer AT highmark DOT com 
********************************



"Stapleton, Mark" 
<mark.stapleton@B 
ERBEE.COM> To
Sent by: "ADSM: ADSM-L AT VM.MARIST DOT EDU 
Dist Stor cc
Manager" 
< [email protected] Subject
.EDU> Re: AW: [ADSM-L] Migration Speed
Has Plummeted 

08/17/2005 09:15 
AM 


Please respond to 
"ADSM: Dist Stor 
Manager" 
< [email protected] 
.EDU> 






Remember that SATA disk has relatively crummy performance when you use
random access to it; SATA's strength lies in sequential access.

--
Mark Stapleton (stapleton AT berbee DOT com )
Office 262.521.5627

________________________________

From: ADSM: Dist Stor Manager on behalf of Joni Moyer
Sent: Wed 8/17/2005 08:02
To: ADSM-L AT VM.MARIST DOT EDU 
Subject: Re: AW: [ADSM-L] Migration Speed Has Plummeted



Hi Michael,

I've looked at my storage pools and they are defined with caching turned
off. This is EMC SATA disk that I have just defined, so I am wondering if
that is my bottleneck at this point. Thanks for the suggestion!

********************************
Joni Moyer
Highmark
Storage Systems
Work:(717)302-6603
Fax:(717)302-5974
joni.moyer AT highmark DOT com 
********************************



"Michael
Garnebode"
<Michael.Garnebod To
e AT T-SYSTEMS DOT COM > ADSM-L AT VM.MARIST DOT EDU 
Sent by: "ADSM: cc
Dist Stor
Manager" Subject
< [email protected] AW: [ADSM-L] Migration Speed Has
.EDU> Plummeted


08/17/2005 08:24
AM


Please respond to
"ADSM: Dist Stor
Manager"
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Hi Joni,

Have a look to your storagepool definition with "q stg f=d"

Migration Processes: 4
Next Storage Pool: WP_AZV01
Reclaim Storage Pool:
Maximum Size Threshold: 500 M
Access: Read/Write
Description: dp_azv01
Overflow Location:
Cache Migrated Files?: Yes
Collocate?:
Reclamation Threshold:
Maximum Scratch Volumes Allowed:
Delay Period for Volume Reuse:

You can update your storagepool definition with "upd stg"

regards

Michael
-----Ursprüngliche Nachricht-----
Von: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] Im Auftrag von
Joni Moyer
Gesendet: Mittwoch, 17. August 2005 14:19
An: ADSM-L AT VM.MARIST DOT EDU 
Betreff: Re: [ADSM-L] Migration Speed Has Plummeted


Hello Everyone!

How do you know if caching is turned on? How/where can you turn it off? I
am having lousy migration speed perfomance as well. What can I look
at/change? I have an AIX 5.2 server at TSM 5.2.4.0 with LTO2 tape drives
attached. Thanks!

********************************
Joni Moyer
Highmark
Storage Systems
Work:(717)302-6603
Fax:(717)302-5974
joni.moyer AT highmark DOT com 
********************************



"David E
Ehresman"
<deehre01@LOUISVI To
LLE.EDU> ADSM-L AT VM.MARIST DOT EDU 
Sent by: "ADSM: cc
Dist Stor
Manager" Subject
< [email protected] Re: Migration Speed Has Plummeted
.EDU>


08/17/2005 08:09
AM


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"ADSM: Dist Stor
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>We back up around 220 Gb of data to the disk pool overnight, then migrate
>(with caching on) to cartridge in the morning.
>

I assume you mean TSM storage pool caching rather than 3390 caching. If
so, I'd turn off caching for a day and see if that makes a difference. It
is my understanding that TSM caching, while optimizing restore times, can
cause performance problems in other TSM areas.

David



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