Gene, I ll try tonight the gzip contribution, for all my file. (mostly Office documents). I have a big forder wich is 11 Go without any compression. With bz2 it compress to 4.1 Go which is nice because it fit in a DVD With gzip it take 4.8Go, and i have to take another dvd or Cd to burn it... I cannot tolerate neither a failure rate even if it's only 0.01 %. All of this folder are extermely important. Ig gzip is more robust, i do not have another choice... Franck On 12/31/05, Gene Heskett <gene.heskett@xxxxxxxxxxx> wrote: > On Friday 30 December 2005 23:56, Franck Y wrote: > >Hi everyone, > > > >I make several backup with bzip2, it seems that he has the better > > compression. > > > >I do my backup like this for several folders. > > > >tar cvf - /home/data/ | bzip2 -9 > /backup/data.tar.bz2 > > > >When i test the archive with bzip2 -t archive.tar.bz2, everything is > >correct when the archive is under 1 Go. But i get CRC error when it's > >upper .... > > > > > >Has anyone experience this ? > > No, other than I've also heard that bzip2 has problems with source > streams above 2GB, which would explain the effect your are seeing. > > As an amanda user myself, it seems rather foolish to make a single > backup file that big considering what you have lost if its > unrecoverable, and bz2 stuff can be entirely too sensitive to the > medium its on. Its demonstrated that to me on many occasions. > > "gzip best", OTOH, is considerably more robust in my experience, and > faster in the compression cycle than bz2. And, when you have a good > backup manager, the individual files can be made fairly smallish so > that each file in the archive remains a manageable size. My amanda > disklist has 44 entries scattered over 2 machines because I've > purposely made each entry only one, under a gigabyte of raw data, > directory tree. Having smallish files means amanda can more easily > manage the storage to make maximum use of the tape it is allowed to > use each night, and I've often filled the tape to 98% capacity without > ever hitting an EOT from the drive. With a mixture of entries that > compress, and those that aren't (because they already are, like rpms & > tar.gz's etc) gzip can routinely reduce 16GB of raw data into 6GB on > the tape, so I don't consider the better compression performance of > bz2 to be an advantage other than in the eye of the beholder. Storage > today is cheap, use what works more dependably rather than that which > may work slightly better, but only 99% of the time. For backups, a 1% > failure rate is unacceptable to me. > > >-- > >Franck > > -- > Cheers, Gene > People having trouble with vz bouncing email to me should add the word > 'online' between the 'verizon', and the dot which bypasses vz's > stupid bounce rules. I do use spamassassin too. :-) > Yahoo.com and AOL/TW attorneys please note, additions to the above > message by Gene Heskett are: > Copyright 2005 by Maurice Eugene Heskett, all rights reserved. > > -- > fedora-list mailing list > fedora-list@xxxxxxxxxx > To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list > -- Franck
