[SOLVED] Backup rsync parameter --chmod=Du+wx and more questions

JZL240I-U · 03-05-2013, 09:22 AM

The command for my (successful) backups is generated by "backintime" as follows

Code:

rsync -rtDH --links -X -pEgo  --delete --delete-excluded  -v  
--chmod=Du+wx  --exclude="/Backup0/me" 
--exclude="/home/me/.local/share/backintime" --include="/home/me/" 
--include="/home/" --exclude=".gvfs" --exclude=".cache*" 
--exclude="[Cc]ache*" --exclude=".thumbnails*" --exclude="[Tt]rash*" 
--exclude="*.backup*" --exclude="*~" --exclude=".dropbox*" 
--exclude="/home/me/lost+found" --include="/home/me/**" 
--exclude="*" /

Most of the parameters I found in the man pages and howtos. Not so --chmod=Du+wx. What does "D" do to the users write and execute permission? Why is chmod needed at all? Permissions should stay as they are originally I'd think...

Would "rsync -aHv --delete --delete-excluded ...{rest of parameters}" not be the same?

Why --include="/home/me/" --include="/home/"? The same, is it not?

What does this do --include="/home/me/**" --exclude="*"?

Any explanation would be highly appreciated

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PTrenholme · 03-05-2013, 10:00 AM

As explained in the man page, the D restricts the chmod to affect only directories. (And, of course, a user needs x and w in order to read and change a directory.)

rknichols · 03-05-2013, 10:22 AM

The "D" makes that --chmod option apply only to directories. Yes, without that option, permissions are copied from the original.

The include/exclude rules can be mystifying even for an experienced user. I'll try to explain some of them.

The --exclude="*" excludes everything not explicitly included. Note that this rule is applied at every stage of directory recursion, so, for example, --include="/home/" would include the /home/directory but everything under it would be excluded by the --exclude="*" unless specifically included by some other rule.
The --include="/home/me/**" includes everything under /home/me (except for things explicitly excluded, such as ".cache*') but, again due to the --exclude="*", this rule would not even be visited without the --include="/home/me/".
Similarly, the --include="/home/me/" rule would not be visited were it not for the --include="/home/" rule.

The "INCLUDE/EXCLUDE PATTERN RULES" section of the rsync manpage includes a rather thorough note about how these rules interact with the "--recursive" (-r) option. Sometimes you have to read through that section several times while looking at your rule set to understand it.

JZL240I-U · 03-06-2013, 01:19 AM

Quote:

Originally Posted by PTrenholme

As explained in the man page...

No, it is not (that is what I wrote and why I asked). At least not in what man pages are installed on my computer, neither, e.g. here http://linux.die.net/man/1/chmod. What are your sources? Thanks for your reply.

@ rknichols Thank you for your explanation

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rknichols · 03-06-2013, 09:31 AM

Quote:

Originally Posted by JZL240I-U

No, it is not (that is what I wrote and why I asked). At least not in what man pages are installed on my computer, neither, e.g. here http://linux.die.net/man/1/chmod.

The "D" is part of rsync's "--chmod" option, and is described in the rsync manpage:

Quote:

In addition to the normal parsing rules specified in the chmod(1)
manpage, you can specify an item that should only apply to a direc-
tory by prefixing it with a ’D’, or specify an item that should
only apply to a file by prefixing it with a ’F’.

JZL240I-U · 03-06-2013, 09:58 AM

Ahhh, okay. In hindsight obvious where I should have looked

. Thanks again

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Would "rsync -aHv" be identical to "rsync -rtDH --links -X -pEgo -v" or do I overlook something?

rknichols · 03-06-2013, 03:38 PM

Quote:

Originally Posted by JZL240I-U

Would "rsync -aHv" be identical to "rsync -rtDH --links -X -pEgo -v" or do I overlook something?

Close. You're adding "-X" (preserve extended attributes), which is not included in "-a", and also adding an extraneous "-E" (preserve executability), which is ignored when "-p" (preserve permissions) is enabled.

PTrenholme · 03-06-2013, 06:32 PM

Quote:

Originally Posted by JZL240I-U

No, it is not (that is what I wrote and why I asked). At least not in what man pages are installed on my computer, neither, e.g. here http://linux.die.net/man/1/chmod. What are your sources? Thanks for your reply.
...

Ah, my bad!

I assumed that, when you said "man page" you meant the rsync manual page. I see from you post that you were speaking about the chmod manual page. I was confused because --chmod is a rsync option, and, as such, well, I just assumed that's what you were talking about.

Sorry.

Anyhow, as I should have said, consult the description of --chmod in the rsync manual pages.

JZL240I-U · 03-08-2013, 03:24 AM

Quote:

Originally Posted by rknichols

Close...

Umm, the second expression is from Backintime. I tried to simplify it. My version should obviously read "rsync -aXHv". Thanks for looking at it and helping

.

Quote:

Originally Posted by rknichols

The "INCLUDE/EXCLUDE PATTERN RULES" section of the rsync manpage includes a rather thorough note about how these rules interact with the "--recursive" (-r) option. Sometimes you have to read through that section several times while looking at your rule set to understand it.

That is what I'm currently doing. These "Filter Rules" become easily fiendishly complex, because the position of any rule in the chain of rules governs rsync's actions (like firewall rules for IPTABLES). Lots of room for thought -- and error

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JZL240I-U · 03-08-2013, 03:27 AM

Quote:

Originally Posted by PTrenholme

...Anyhow, as I should have said, consult the description of --chmod in the rsync manual pages.

No need for blushes. As you can see I didn't even notice that chmod in ths case is a parameter of rsync and as such will be desribed in the rsync-man page (where I found it in the mean time)...

Thanks for your help and patience

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