The numbers TSM reports are ALL from the server's point of view. A "filling" tape will have a fixed (and pretty meaningless) EST CAP determined by the device class until the tape gets marked FULL. Then TSM changes EST CAP to the number of bytes actually written to the tape.
With tape drives that can do outboard compression, the TSM server can't really know how much is going to fit on a tape. All it knows is how many bytes it wrote on the bus to the tape drive before the drive signalled back that the tape is full. So if the clients aren't compressing data, and TSM is writing to a tape drive that is doing compression, you can get HUGE variations in the amount of bytes TSM reports sending to a tape. Some data compresses better than others. For example, ASCII text files compress a whole lot, but .gif and .tif and .zip files are already compressed, so they usually don't compress more when sent out to the drive. If the client compresses the data FIRST, you see less variation in the amount of bytes written to your tapes, because they data doesn't compress much more when sent to the drive. Your stats look normal to me. -----Original Message----- From: Robert Ouzen [mailto:[EMAIL PROTECTED] Sent: Thursday, January 22, 2004 11:46 AM To: [EMAIL PROTECTED] Subject: Cartridge Estimated capacity Hi to all Can anybody tell me why the huge difference between the numbers of Estimated Capacity of a full cartidge DLT8000 (40/80 G). The format of the devclass was configure to DRIVE. The nodes are backup without compression . Here the output of the q vol. Volume Name Storage Device Estimated Pct Volume Pool Name Class Name Capacity Util Status (MB) ------------------------ ----------- ---------- --------- ----- -------- 000002 SCA_UNIX SCALARCLA- 58,089.8 96.5 Full SS 000009 SCA_UNIX SCALARCLA- 165,222.0 64.6 Full SS 000016 SCA_UNIX SCALARCLA- 76,230.3 49.1 Full SS 000027 SCA_UNIX SCALARCLA- 65,272.7 40.9 Full SS 000034 SCA_UNIX SCALARCLA- 80,000.0 3.9 Filling SS 000044 SCA_UNIX SCALARCLA- 136,684.2 62.8 Full SS 000111 SCA_UNIX SCALARCLA- 48,768.3 44.5 Full SS 000141 SCA_UNIX SCALARCLA- 51,704.7 40.6 Full SS 000158 SCA_UNIX SCALARCLA- 70,574.6 97.3 Full SS 000159 SCA_UNIX SCALARCLA- 80,000.0 62.9 Filling T.I.A Regards Robert Ouzen E-mail: [EMAIL PROTECTED]