If VTS is artifically configured TSM server backend this leads to another question - virtual volumes performance. We read recently on the list that TSM using VTS is having not so good performance. Is this true or not I cannot prove and cannot have clear opinion. But virtual volumes are by definition TSM server backing up to TSM server. And if TSM-TSM performance is good why not TSM-VTS (i.e. TSM) performance be good? And how we can define "good" or "better" or "average"? If TSM-VTS is performing "not so good" is TSM-TSM having similar performance (measured in GB/hour or something similar)? If both perform at comparable speeds can we say both are "not so good" or TSM-TSM performs better? Sorry for asking so many questions. I have no mainframe (and VTS) to answer them by myself.
Zlatko Krastev IT Consultant Michael Bartl <[EMAIL PROTECTED]> on 03.12.2001 10:48:11 Please respond to [EMAIL PROTECTED] To: [EMAIL PROTECTED] cc: Subject: Re: TSM and VTS I remember from an IBM presentation a few years ago that the technology behind VTS is TSM. So using a VTS library on a TSM server means stacking the same intelligent tape management technology for two instances. This can eliminate some of the benefits. On one hand, when collocation is "inactivated" by VTS, access performance to your data may drop. On the other hand, VTS uses quite a lot of disk caching to improve performance. It depends on the structure of a TSM servers data, whether the gain or loss in performance will be stronger. Best regards, Michael -- Michael Bartl mailto:[EMAIL PROTECTED] Office of Technology, IT Germany/Austria Tel: +49-89-92699-806 Cable & Wireless Deutschland GmbH. Fax: +49-89-92699-302 Landsberger Str. 155, D-80687 Muenchen http://www.cw.com/de Bill Mansfield wrote: > > The fact is that TSM does not always write tapes 'til they are full. If > you have a bunch of small nodes using collocation or backupsets, you can > wind up with a lot of expensive tape with little content. Using the VTS > would allow you to stack these nearly empty tapes onto one tape. I'm not > sure whether this defeats the purpose of collocation, since I'm not sure > that the virtual tapes will stay collocated inside the VTS, though. > > _____________________________ > William Mansfield > Senior Consultant > Solution Technology, Inc >
