"ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> wrote on 08/20/2003 07:54:54 AM:
> "No query" restore has nothing to do with minimizing tape mounts for > restore. For a given restore, TSM mounts each needed tape once and only > once, and reads it from front to back. > > The most visible benefit of no query restore is that data starts coming > back from the server sooner than it does with "classic" restore. With > classic restore, the client queries the server for all objects that match > the restore file specification. The server sends this information to the > client, then the client sorts it so that tape mounts will be optimized. > However, the time involved in getting the information from the server, > then sorting it (before any data is actually restored), can be quite > lengthy. No query restore lets the TSM server do the work: the client > sends the restore file specification to the server, the server figures out > the optimal tape mount order, and then starts sending the restored data to > the client. The server can do this faster, and thus the time it takes to > start actually restoring data is reduced. > > In either case, for a given restore, TSM will restore the files and > directories in a manner that optimizes tape mounts. If it so happens that > a file is restored before it's parent directory is restored, then the > client will create the parent directory, restore the file, then restore > the parent directory when it encounters it in the restore sequence. > > Regards, > > Andy > > Andy Raibeck > IBM Software Group > Tivoli Storage Manager Client Development Excellent post. Clear and well written. This should be in the FAQ (if it's not already).
