rsync question -

[Bob Goodwin]

Is rsync not supposed to append to the existing files or just copy over 
them?

I would like to update /home/bobg/.thunderbird but the following simply 
overwrites everything:

[root@box10 bobg]# rsync -avz /mnt/HOME1/bob/TBdBx07/ 
/home/bobg/.thunderbird/

In this case I have rsynced .thunderbird from box7 to an nfs server file 
TBdBx07 and am in turn applying that to box10. I also want to do the 
same with F20-Beta in Vmware Workstion which is how I got off on this ...

Do I misunderstand or am I simply doing it wrong?

Bob

-- 
http://www.qrz.com/db/W2BOD
Box 7 Fedora-19/64 XFCE Linux

[Bob Goodwin]

On 15/11/13 12:53, Rick Stevens wrote:
>  No, you're not misunderstanding it. rsync looks at the source and
>  target and if there are differences, it copies from the source to the
>  target. In your case, you told rsync to copy everything inside the
>  /mnt/HOME1/bob/TBdBx07 directory (the source) to the
>  /home/bobg/.thunderbird directory (the target). If there are differences
>  between those two directories, rsync will try to make the target look
>  like the source as much as possible. Unless you add the "-u" option,
>  rsync will even overwrite files on the target that are "newer" than
>  those on the source.
>
>  The "-a" option to rsync tells it to try to do an archive (keep all
>  attributes, recurse down directories, etc.) and the "-z" means
>  "compress data during the transfer" (sorta silly when everything's on
>  the same LAN...it's more intended for WAN use). You probably wanted
>  "-avu --ignore-existing" to keep rsync from overwriting existing files
>  on the target (rsync will only copy over files that do NOT exist on the
>  target).
>
>  rsync is a very powerful tool, but as with all powerful tools, one
>  can easily injure oneself. Use adequate safety equipment and read the
>  manual! :-)  
Ok that appears to have done what I wanted, at least it transferred a 
lot less data in very little time. I  thank you for the clear 
explanation. I have trouble understanding the man pages but on a good 
day I do answer my own questions.

Thanks,

Bob

-- 
http://www.qrz.com/db/W2BOD
Box 10 Fedora-19/64 XFCE Linux

[Rick Stevens]

On 11/15/2013 09:17 AM, Bob Goodwin - Zuni, Virginia, USA issued this 
missive:
>  Is rsync not supposed to append to the existing files or just copy over
>  them?
>
>  I would like to update /home/bobg/.thunderbird but the following simply
>  overwrites everything:
>
>  [root@box10 bobg]# rsync -avz /mnt/HOME1/bob/TBdBx07/
>  /home/bobg/.thunderbird/
>
>  In this case I have rsynced .thunderbird from box7 to an nfs server file
>  TBdBx07 and am in turn applying that to box10. I also want to do the
>  same with F20-Beta in Vmware Workstion which is how I got off on this ...
>
>  Do I misunderstand or am I simply doing it wrong? 
No, you're not misunderstanding it. rsync looks at the source and
target and if there are differences, it copies from the source to the
target. In your case, you told rsync to copy everything inside the
/mnt/HOME1/bob/TBdBx07 directory (the source) to the
/home/bobg/.thunderbird directory (the target). If there are differences
between those two directories, rsync will try to make the target look
like the source as much as possible. Unless you add the "-u" option,
rsync will even overwrite files on the target that are "newer" than
those on the source.

The "-a" option to rsync tells it to try to do an archive (keep all
attributes, recurse down directories, etc.) and the "-z" means
"compress data during the transfer" (sorta silly when everything's on
the same LAN...it's more intended for WAN use). You probably wanted
"-avu --ignore-existing" to keep rsync from overwriting existing files
on the target (rsync will only copy over files that do NOT exist on the
target).

rsync is a very powerful tool, but as with all powerful tools, one
can easily injure oneself. Use adequate safety equipment and read the
manual! :-)
----------------------------------------------------------------------
- Rick Stevens, Systems Engineer, AllDigital    ricks(a)alldigital.com -
- AIM/Skype: therps2        ICQ: 22643734            Yahoo: origrps2 -
-                                                                    -
----------------------------------------------------------------------

[Cameron Simpson]

On 15Nov2013 17:19, Bob Goodwin <bobgoodwin(a)wildblue.net&gt; wrote:
>  Ok that appears to have done what I wanted, at least it transferred
>  a lot less data in very little time. 
One thing I think Rick may have missed out is that if a file is
similar on the target (eg it had just grown on the source, implying
"append" to the target) then while rsync will make a whole new
target file (as a temp file until it is complete) it just sends
checksums for the overlapping data; if the checksums match then the
data in the new temp files is copied from the existing target to
the temp file. Only different data is sent from the source. Once
complete, the temp file is switched in to replace the former target
file.

Cheers,
-- 
Cameron Simpson <cs(a)zip.com.au&gt;

When in doubt, gas it. It may not solve the problem, but it ends the suspense.
        - Steve Moonitz (92 Ducati 900ss) <stevem(a)ew.timeinc.com&gt;