If the large files are SEQUENTIALLY written files, a fuzzy backup is usually OK. An example of this is the dsmsched.log file - it's always being written to during a backup. Same thing on some AIX clients that have sequentially written logs. We set up a special management class with SHARED DYNAMIC and use that for these files. Usually what you get is a backup of the file UP TO THE POINT that was being written at the time TSM tried to backup, and that is fine (and certainly better than nothing).
However, if the files are DATA BASES of some kind where the changes could be made in the middle of the file, DON"T use SHARED DYNAMIC. You will get a backup that looks oK, but when you restore it, you could have damage in the middle somewhere that will not be apparent until you try to access that record. For files like this, you have to figure out what program is using the file, and schedule your backups sometime when you can shut it down. Or use a TDP, if it's a data base. Or export the data to a flat file and back up the flat file. There are many techniques, depending on your circumstances. . -----Original Message----- From: Scott Walters [mailto:[EMAIL PROTECTED]] Sent: Thursday, October 03, 2002 2:17 PM To: [EMAIL PROTECTED] Subject: Copy Serialization Dynamic Impact Hey all, In setting up our TSM server, we've noticed that many clients have large sessions because they have been re-transmitting files that are changing. We had the Copy Serialization set to Shared Dynamic CHANGINGRETRIES=4. We then bumped CHANGINGRETRIES down to 1. At this point we still have a few boxes that are backing up large files that are being retransmitted. We've now set the Copy Serialization to Dynamic. Our previous backup product, StorageTek's CAM, had no changing retries feature and we never had any problems. But there is no gurantee TSM and CAM backup a changing file the same way. The TSM Admin User guide warns that this can result in a 'fuzzy copy'. Has anyone had a negative experience with fuzzy copies? -- Scott Walters Packet Pusher - "The world speaks IP" Mack Trucks, WHQ http://www.MackTrucks.com 2100 Mack Boulevard Ph: 610.709.3728 Allentown, PA 18103 Fx: 610.709.2809
