Re: [Bug-tar] Monthly backup doesn't expand files, but which are in the archive

[Tim Kientzle]

> On Aug 29, 2016, at 6:13 AM, Steffen Nurpmeso <address@hidden> wrote:
> 
> I've changed it back to how it was all the time, and only use "|
> xargs -0 tar -r -f $ar", adding the compression step later on.

The -r option is pretty expensive; it has to read the entire existing archive 
from the beginning to identify the end of the last entry, then it can write new 
entries from that point (overwriting any final padding).

If you want to select the files with a separate mechanism, then you really 
should use -I or -T or list= or other equivalent option (depending on the 
particular tar implementation you're using).

(Also, be careful to not include directories in your generated file list -- tar 
by default will walk those directories and include all the contents, which can 
result in many duplicate copies.)

Cheers,

Tim