[olug] To RAID or not to RAID

[Obi-Wan]

On 09/22/2014 06:19 PM, Lou Duchez wrote:
> Any chance you've got a friend out there on the Internets who would 
> let you keep a drive at his place?  For my remote backups, I do a 
> two-step process:
>
> 1)    rsync is a great way to back data up across a network (including 
> the Ethernet), especially where only a little data changes from one 
> backup session to the next.  So let's say I use rsync to back up my 
> data to "/backups/current" on the remote system.  Which I then follow 
> with step 2 ...
>
> 2)    /bin/cp -al /backups/current /backups/[date]
>
> What that does is create a dated backup directory, but thanks to the 
> magic of the "-l" flag, hard links (not symbolic links) to the files 
> in /backups/current are created.  That means I have a logical copy of 
> /backups/current that takes up almost no additional drive space 
> because it's pointing to the same files on the file system.  Now, if 
> any of those files in /backups/current is changed the next time I run 
> rsync, the file in /backups/current is unlinked first and a new file 
> is created -- but the link to the original in /backups/[date] is left 
> completely untouched.

I don't see anything in the rsync man page that indicates it will break 
that hard link when updating an existing file.  How does your setup 
ensure this will happen?  If the link isn't broken, then your old 
hardlinks will get updated along with your current file when rsync 
changes it.

-- 
*Ben "Obi-Wan" Hollingsworth* obiwan at jedi.com <mailto:obiwan at jedi.com> 
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