Re: FreeBSD, DLT 2000 and hardware compression ...
I have a DLT2000 (is that 5/10 or 15/30?) ... If I'm reading the www.quantum.com web page right, it's 10/20 if you use DLT-III tapes and 15/30 if you use DLT-III-XT. will it automatically use hardware compression under FreeBSD, or, like Solaris, do I have to use special devices for this? This is a guess because I don't have FreeBSD (and nobody else has chimed in), but the (FreeBSD) man page has a "comp" option that appears to be able to turn compression on and off. If I were you, I'd add that command to your own wrapper script around amdump (and amflush) so you know it is set to the proper value every time. Marc G. Fournier John R. Jackson, Technical Software Specialist, [EMAIL PROTECTED]
Re: FreeBSD, DLT 2000 and hardware compression ...
which man page are you reading here? :) www.freebsd.org John R. Jackson, Technical Software Specialist, [EMAIL PROTECTED]
Re: FreeBSD, DLT 2000 and hardware compression ...
On Tue, 6 Feb 2001, John R. Jackson wrote: which man page are you reading here? :) www.freebsd.org I think he meant man page for which command. (You overlooked saying in your last message.) I imagine you're looking at mt(1) which contains: comp Set compression mode. There are currently several possible values for the compression mode: offTurn compression off. on Turn compression on. none Same as off. enable Same as on. IDRC IBM Improved Data Recording Capability compression (0x10). DCLZ DCLZ compression algorithm (0x20). In addition to the above recognized compression keywords, the user can supply a numeric compression algorithm for the tape drive to use. In most cases, simply turning the compression `on' will have the desired effect of enabling the default com- pression algorithm supported by the drive. If this is not the case (see the status display to see which compression algo- rithm is currently in use), the user can manually specify one of the supported compression keywords (above), or supply a nu- meric compression value. Sorry, I haven't messed with this myself. I'm currently staring at the Linux docs trying to figure out if I have to use ioctl in order to turn h/w compression on and off there. -Mitch
Re: FreeBSD, DLT 2000 and hardware compression ...
On Tue, Feb 06, 2001 at 10:36:19PM -0500, Mitch Collinsworth wrote: Sorry, I haven't messed with this myself. I'm currently staring at the Linux docs trying to figure out if I have to use ioctl in order to turn h/w compression on and off there. Should be able to do it with mt(1). At least, that's what I once did with a DLT-2000. You might want to get the latest source. There seem to be an awful lot of copies scattered over the net. A search on www.tuxfinder.com for mt-st located mt-st-0.6.tar.gz, newer than the 0.5b that mostly turned up. It was on a mirror of metalab, previously sunsite.unc.edu, now www.ibibio.org. http://www.ibiblio.org/pub/Linux/system/backup/mt-st-0.6.tar.gz The 0.6 manpage notes that mt uses the MTCOMPRESSION ioctl, but that this doesn't work on all tape drives. -- - Dan Wilder [EMAIL PROTECTED] Technical Manager Correspondent SSC, Inc. P.O. Box 55549 Phone: 206-782-7733 x123 Seattle, WA 98155-0549 URLhttp://www.linuxjournal.com/ -
