I'll just add that using tar -z to archive is a bad idea for another reason too. Typically a tape drive will do hardware compression as files are written to the tape. Hardware compression is faster and more efficient than software compression and generally it IS the best choice. Using both hardware and software compression will almost always result in a larger file than just using one or the other. Plus, as Trevor mentioned, software compression to end up with one BIG file can result in an unusable archive.
Kev. ----- Original Message ----- From: "Trevor Lauder" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, December 03, 2003 5:25 PM Subject: [clug-talk] afio & mt quick file restore question I've been searching for years now on any good documentation on how to use the byte offset value that afio gives you when using the -B -Z options in 'mt /dev/st0 seek' to do quick selective file restores (fast forward to the location of the file) without having to possibly read the entire tape just to restore one file. I've been unable to find any good documentation on using afio / mt in this manner (Seems afio is one of those top notch programs that lack good documentation :) Does anyone on this list have any experience with using afio / mt like this? I know there are other ways to accomplish this using tar but I'm not interested in those methods as there is too big a chance of corruption to the backups. Both tar (with compression) and cpio are inferior to afio in this aspect and maybe I should put out a warning considering the recent talk on using tar for backups. If you are compressing your tar archives (tar.gz, tar.bz, etc) and that file becomes corrupt for whatever reason (bad block, bad tape, etc), you will not be able to recover any file past that point in the archive which makes your backup pretty much useless. I would not consider compressed tar files a safe solution for backups. tar without compression does not suffer from this problem, if a non-compressed tar file becomes corrupt you would still be able to restore any files in the archive before & after the point of corruption. That is the background information on why I am using afio. Any help with using afio / mt for quick selective restores would be appreciated. Cheers, Trevor _______________________________________________ clug-talk mailing list [EMAIL PROTECTED] http://clug.ca/mailman/listinfo/clug-talk_clug.ca _______________________________________________ clug-talk mailing list [EMAIL PROTECTED] http://clug.ca/mailman/listinfo/clug-talk_clug.ca
