1. Try turning it off. If that doesn't use more tapes, then something else is wrong - like the tape drive is ignoring it - or the kernel driver is silently dropping the request
2. Also, try setting variable length records - I seem to remember this makes the driver write out records of the size that the application specifies, instead of the default block size. Its been a while since I've had to play with things, but I found out a lot when I did (and after taking the tapes to another system and reading them on a different OS - item #2 above was a real surprise! --Bruce Benjamin Scott wrote: > List, > > Does anyone here know how to tell a Quantum DLT 7000 SCSI tape drive to > turn on hardware compression under Linux (for use with "tar" and the like)? > I have tried "mt compression 1" and "mt setdensity 0x85" and "mt defdensity > 0x85", but none of them seem to have any affect. At least, they do not > appear to. It takes the same amount of time and same number of tapes to > backup the same data set, regardless of settings. I would imagine *some* > variation with compression turned on, even if the data does not compress > well (indeed, in that case, it is supposed to take *longer*). > > The drive is inside a tape changer, so looking at the front-panel LEDs is > difficult. :-) > > I am hoping someone here has played around with hardware data compression > under Linux before. Or under any Unix, for that matter. Information on > this is proving scarce. > > System information: > > Red Hat Linux 6.2 > Linux kernel 2.2.19 > GNU C library (glibc) 2.1.3 > mt-st version 0.5b > > advTHANKSance > > -- > Ben Scott | Net Technologies, Inc. | 978-462-8795 > Network Engineer | Salisbury, MA, USA | 866-NTI-LINUX (684-5468) > [EMAIL PROTECTED] | http://www.ntilinux.com | Fax: 978-499-7839 > > ***************************************************************** > To unsubscribe from this list, send mail to [EMAIL PROTECTED] > with the text 'unsubscribe gnhlug' in the message body. > ***************************************************************** -- For the latest CodeMeta news, go to http://www.codemeta.com/news . For my personal news, go to http://www.milessmithfarm.net/news . ***************************************************************** To unsubscribe from this list, send mail to [EMAIL PROTECTED] with the text 'unsubscribe gnhlug' in the message body. *****************************************************************
