On Saturday 19 August 2017 23:07:01 Celejar wrote: > On Thu, 17 Aug 2017 11:47:34 -0500 > > Mario Castelán Castro <marioxcc...@yandex.com> wrote: > > Hello. > > > > Currently I use rsync to make the backups of my personal data, > > including some manually selected important files of system > > configuration. I keep old backups to be more safe from the scenario > > where I have deleted something important, I make a backup, and I > > only notice the deletion afterwards. > > > > Each backup snapshot is stored in its own directory. There is much > > redundancy between subsequent backups. I use the option > > "--link-dest" to make hard links and thus save space for files that > > are *identical* to an already-existing file in the backup > > repository. but this is still inefficient. Any change to a file, > > even to its metadata (permission, modification time, etc.), will > > result in the file being saved at whole, instead of a delta. > > > > Can you suggest a more efficient alternative? > > There's Borg, which apparently has good deduplication. I've just > started using it, but it's a very sophisticated and quite popular > piece of software, judging by chatter in various internet threads. > > https://borgbackup.readthedocs.io/en/stable/ > > Celejar Amanda has quite intelligent ways to do that. I run it nightly and have been since the late 90's. Storage in my case is in what are called v-tapes, which in fact are directories on a separate, terrabyte drive. However, unlike tapes which are time burning sequential reading devices, the terrabyte drive is true random access, so recovery operations are about 1000x faster than real tapes. Not to mention the terrabyte drive is about 1000 times more dependable than tape can ever be.
That drive had 25 re-allocated sectors when smartctl came out all those years ago, and still has that same 25 sectors marked bad and re-assigned right now. 5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 25 240 Head_Flying_Hours 0x0000 100 253 000 Old_age Offline - 66095 (35 137 0) Pretty good for coming up on 67,000 head flying hours... :) Seagate Barracuda's of course, pure "commodity drive" at less than a $70 bill. But when I do replace them, the first thing I do is goto the Seagate site and download the latest firmware for that drive to a cd, reboot to it and let it update the drives firmware if it finds old firmware. What you buy from the box houses is often first run stuff and may be 20 revisions out of date. The drive will probably be faster, once going from 26 megabytes/second to a hair over 120 megabytes/second. Sata is slow, old Asus mainboard shows under 3GB/sec: root@coyote:/etc/avahi# hdparm -tT /dev/sdc /dev/sdc: Timing cached reads: 4882 MB in 2.00 seconds = 2441.26 MB/sec Timing buffered disk reads: 348 MB in 3.00 seconds = 115.84 MB/sec Amanda and I have had our differences, but at the end of the day, it Just Works(TM). And has been for around 18 years here. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene>
