Best way to incremental backup disk to disk ???

[mzraptor]

Hello,

I'm relatively new on Linux and use for fileserver a CentOS 5.6 box, that has one main OS HDD (sda, for which data I don't really care, as I can easily setup again) and 3 other drives.

Due to the fact that my motherboard does not support RAID and bad experiences I had on past with software raid on linux, I am looking for a more reliable way to setup an automated backup operation.


A few hints:

-the 3 drives are sata2, 1 TB each and are connected as:
/dev/sdb, mounted under /home/disk1,
/dev/sdc, mounted under /home/disk2,
/dev/sdd, mounted under /home/disk3.

-I need only 1 TB for my file storage needs, thus I am willing
to have the other two drives as backup drives, so that I can
keep daily and weekly backups.



What would be the easiest way to make this operation under CentOS 5.6 ???

I have heard best option would be rsync & crontab, anyone know if that's the best option and if this will be the faster and most reliable option ?

Could you please help me how this can be setup ?

I want the backup process to only backup changed files as it's waste of time and resources to rewrite everything daily and weekly...



Thanks everyone for reading and your response!

[HROAdmin26]

Google: rsync changed files

man rsync

...
Rsync  finds  files that need to be transferred using a "quick check" algorithm (by default) that looks for files that have changed in size or in
       last-modified time.  Any changes in the other preserved attributes (as requested by options) are made on the destination file directly  when  the
       quick check indicates that the file’s data does not need to be updated.
...

As the manual states, rsync's default behavior is only to copy changed files.

If you want to keep *versions* of changed files, you could look at rdiff-backup.

[hans51]

as above
rsync
but in addition to crontab
make an ICON on your desktop, to manually do a backup every time you have added new or made major changes
I do rsync multiple drives and most of the backups take less than a minute
hence when ever I go out of office or make a brake,
most of the time my rsync backup takes less than a minute for a 500 GB system drive backup
I do lots of photos, and have all on an external plus another backup just for pics
backup procedure same there
I hit my backup icon
just in case something would happen before crontap or laptop is down at crontab time

[zackwasa]

Try using dirvish from Welcome to Dirvish
It makes use of rsync, it is highly configurable and using hard links it creates snapshots of daily weekly or monthly backups where only the changed files are copied

[mzraptor]

I think I'll be ok with rsync daily and weekly crontab to mirror the disk1 to disk2 and 3,
could anyone help how the syntax should be for this to work properly ?

my original files reside in /home/disk1
daily mirror should go to /home/disk2
and weekly would go to /home/disk3

how would the syntax/command for crontab daily and weekly be setup for this ?


Thanks on advance for the help

[mzraptor]

I have setup it to do:

00 1 * * * rsync –av /home/disk1 /home/disk2
00 5 * * 0 rsync –av /home/disk2 /home/disk3

I suppose its properly done to backup every night (daily) all disk1 to disk2 at 1:00 am,
and to do also a weekly backup every Sunday all disk2 to disk3 at 5:00 am
(giving also a 4 hrs execution time for daily operation to complete)


Please let me know if that's correct or what I do wrong...

I see after execution, in disk2 there's a folder named disk1 and inside that is the contents of disk1...

How could this be made so it doesn't use a folder and just sync all data ?

Also, what happens if a file is deleted in disk1, will it also be deleted in backups when cron runs ?