Silly problems with "tar" in commandline...

Sabinou · 10-24-2007, 06:24 PM

Hello there

I am a bit ashamed to ask such a question after five years I switched to linux, but I remained globally hostile to command line mode unless I couldn't avoid it...

And here, I need to have a command line function work, and I don't manage to have a parameter understood.
I will be grateful if you help

The command is very simple, it's tar. I can log into my server's storage with ssh and then backup everything, file permissions and all, it's the best for a backup. But I don't manage to exclude a precise folder

Quote:

tar -cvf bak20071024.tar *

This one works. But I don't find how I can have a correct syntax to exclude a folder called "test"

I saw two possibilites with tar's manual :

Code:

   --exclude=PATTERN
              exclude files matching PATTERN

   -X, --exclude-from=FILE
              exclude files matching patterns listed in FILE

But here I don't want to exlude all files whose names contain "test", only the folder called like that...

Do you see how I could write that tar command line to add to my archive everything but the "test" folder ?
Thanks a lot if you can help me !

docalton · 10-24-2007, 06:57 PM

You are on the right track.

tar -cvf bak20071024.tar * --exclude=test

That should work. I would keep an eye on it or perhaps redirect the output to a file so you can take a look at the contents to make sure you are not missing anything important.

Hope this helps

davimint · 10-24-2007, 07:30 PM

Just for kicks I had to try that..
This worked fine on my home directory and excluding the BL directory

Code:

tar --exclude=BL -cvf mybackup.tar /home/david/

Hope that helps..

Sabinou · 10-25-2007, 03:11 AM

Thank you guys, I appreciate it

However, I just saw that the default tar option, even without exclusion, didn't fully work ?!?

After tar-ing about one third of the files and folders, the list of the archived elements is replaced with a list of the bugged elements...

The ssh-server message is :
tar: tell_a_friend.php: ne peut stat: Aucun fichier ou ré�pertoire de ce type

you could transated as :
tar: tell_a_friend.php: can't stat: no such file or folder

Do you have any idea why that problem occured ? I am puzzled...

jschiwal · 10-25-2007, 03:39 AM

You are probably backing up a live system. The file may have been removed before it could be backed up, or you tried to follow a dead link. Or you could have a correct directory (a file from the kernels point of view).

I don't know which directories you are trying to backup. Backing up the root directory without excluding /tmp, /dev, /tmp and other directories may not be the best idea.

I'm not certain, but if you use the -g <snapshot-file> option when creating an archive, it may ignore files that were altered after the start of the tar job. See section 5.2 of the info manual for examples of using snapshot files and incremental backups.

uncle-c · 10-25-2007, 03:57 AM

Thanks for the "-g" option hint jschiwal. A very useful tip indeed !!!!

Sabinou · 11-04-2007, 06:57 AM

And thanks too for the kind help

As for me, this is indeed to save the files from a live server (in mutualized [or should I say "shared", in english ?] hosting, so fortunately there is no filesystem to save, it's only that it's possible that cache, cookies and session files might differ from the beginning to the end of the archiving.
I'm saving everything in www/*

I made tests, and the bug only occurs when i try to exlude things from the archiving, I simply gave up on the exclusion.

However, I just only saw that tar -cvf bak.tar * does NOT save .htaccess files for me o.O
Would you guys imagine why ?
The options for the tar never spoke about ignoring or not ignoring hidden files... I am troubled...

ptossy · 11-04-2007, 07:27 AM

How about
find . -print | grep -v ^\./test | xargs tar -cvf bak.tar

Sabinou · 11-05-2007, 01:44 AM

Quote:

Originally Posted by ptossy

How about
find . -print | grep -v ^\./test | xargs tar -cvf bak.tar

That generated an archive 20 times bigger than the norm containing several du plicates of ALL files on the server, I guess that didn't work as planned

Disillusionist · 11-05-2007, 02:12 AM

Your problem is with the use of *

if you try:

Code:

tar cvf testing.tar ./ --exclude test

This will tar all files starting with current directory (including hidden files) excluding any files or folders called "test"

This will error on testing.tar as this is the backup file and would be created in the directory that it is backing up, however it will do everything else that you requested.

Disillusionist · 11-05-2007, 02:24 AM

Quote:

Originally Posted by ptossy

How about
find . -print | grep -v ^\./test | xargs tar -cvf bak.tar

This causes duplicates because it is passing the directories as well as the contents of the directories.

You could use the '-type d' option to just pass directories but then you would still have subdirectories being passed (hence duplicates), the best that you could do is have it find only files '-type f', but not sure how this would handle named pipes and symbolic links.

Also, why bother? seems an extreeme measure to pass info into tar in this way.