How you connect to the disk storage (i.e., SCSI or SAN) doesn't matter. This goes more to the issue of how blocks within the volumes are laid out on the spindles. formatting them one at a time will cause the blocks to be laid out in a more sequential fashion, so that when TSM references the blocks, they will be referenced in a more sequential fashion (assuming you are doing mostly sequential I/O).
..Paul At 02:02 PM 10/20/2010, Zoltan Forray/AC/VCU wrote: >Thanks for the affirmation. This is what I have been seeing/experiencing. > As soon as I can empty the stgpool (5TB), I will define fixed volumes and >see how much difference that makes. I am aware of the issue of >single-threading the define/formats to not fragment them, however I wonder >how much that really matters in a SAN? >Zoltan Forray >TSM Software & Hardware Administrator >Virginia Commonwealth University >UCC/Office of Technology Services >zfor...@vcu.edu - 804-828-4807 >Don't be a phishing victim - VCU and other reputable organizations will >never use email to request that you reply with your password, social >security number or confidential personal information. For more details >visit http://infosecurity.vcu.edu/phishing.html > > > >From: >Markus Engelhard <markus.engelh...@bundesbank.de> >To: >ADSM-L@VM.MARIST.EDU >Date: >10/20/2010 09:20 AM >Subject: >[ADSM-L] Lousy performance on new 6.2.1.1 server with SAN/FILEDEVCLASS >storage >Sent by: >"ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> > > > >Hi Zoltan, > >my experience has been: use fixed size preformatted volumes, and be sure >to >format them sequentially, even if it seems to take a hell of a time. But >then, it´s a one-time action and highly automated, so just don´t try to >boost "performance" here. Make sure no one else is bogging perfs, SAN guys >sometimes tend to put all kinds of unassorted loads on one storage array >producing massive hot-spots during TSM activities. > >Kind regards, > >Markus > > >-- >Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte >Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail >irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und >vernichten Sie diese E-Mail. Das unerlaubte Kopieren sowie die unbefugte >Weitergabe dieser Mail oder von Teilen dieser Mail ist nicht gestattet. > >Wir haben alle verkehrsüblichen Maßnahmen unternommen, um das Risiko der >Verbreitung virenbefallener Software oder E-Mails zu minimieren, dennoch >raten wir Ihnen, Ihre eigenen Virenkontrollen auf alle Anhänge an dieser >Nachricht durchzuführen. Wir schließen außer für den Fall von Vorsatz oder >grober Fahrlässigkeit die Haftung für jeglichen Verlust oder Schäden durch >virenbefallene Software oder E-Mails aus. > >Jede von der Bank versendete E-Mail ist sorgfältig erstellt worden, >dennoch >schließen wir die rechtliche Verbindlichkeit aus; sie kann nicht zu einer >irgendwie gearteten Verpflichtung zu Lasten der Bank ausgelegt werden. >______________________________________________________________________ > >This e-mail may contain confidential and/or privileged information. If you >are not the intended recipient (or have received this e-mail in error) >please notify the sender immediately and destroy this e-mail. Any >unauthorised copying, disclosure or distribution of the material in this >e-mail or of parts hereof is strictly forbidden. > >We have taken precautions to minimize the risk of transmitting software >viruses but nevertheless advise you to carry out your own virus checks on >any attachment of this message. We accept no liability for loss or damage >caused by software viruses except in case of gross negligence or willful >behaviour. > >Any e-mail messages from the Bank are sent in good faith, but shall not be >binding or construed as constituting any kind of obligation on the part of >the Bank. -- Paul Zarnowski Ph: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801 Em: p...@cornell.edu