Depending on your OS version, there can be a -L flag on the tar command. This refers to a list file that you can populate beforehand. In you case:-
It's not too common, but a really good option and it's in AIX at least. What OS are you using?
It's extremely useful for extracting lots of files from a huge tar-file, i.e.
...edit the list file created to keep just the ones you want, then ....
Another option might be to ignore or handle the backup error. The tar-file you create won't have it anyway, so is that all you really need?
I hope that this helps,
Robin
Liverpool/Blackburn
UK
From within a directory, how do I determine whether I have write permission for it.
test -w pwd ; echo ?
This doesn't work as it returns false, even though I have write permission. (4 Replies)
I want to make an automated system to compile & run the source codes from different persons and to tell if the output is the same with the standard one(wich is given by me). Ok, this is quite simple, but the tricky part is,how do I avoid the "bad intentions" that may result from running those... (2 Replies)
HI,
if I have a tarfile called pmapdata.tar that contains
tar -tvf pmapdata.tar
-rw-r--r-- 0/0 21 Oct 15 11:00 2009 /var/tmp/pmapdata/pmap4628.txt
-rw-r--r-- 0/0 21 Oct 14 20:00 2009 /var/tmp/pmapdata/pmap23752.txt
-rw-r--r-- 0/0 1625 Oct 13 20:00 2009... (1 Reply)
I want to backup all the directory tress, including hidden directories, without copying any files.
find . -type d gives the perfect list.
When I tried tar, it won't work for me because it tars all the files.
find . -type d | xargs tar -cvf a.tar
So i tried rsync.
On my own test box, the... (4 Replies)
Hi,
How do i check if I have read/write/execute rights on a UNIX directory?
What I'm doing is checking read access on the files but i also want to check if user has rights on the direcory in whcih these files are present.
if then......
And I check if the directory exists by using... (6 Replies)
we want to allow user to FTP files into a directory, and then the program (PLSQL) will read and process the file, and then move the file to other directory for archiving.
the user id: uftp1, group: ftp
the program run in oracle database, thus have the user Id: oraprod, group: dba
how to... (2 Replies)
i have an application that writes to a directory. let's call the directory:
/var/app/
the permissions of this directory is:
drwxrwxr-x
Now the files that the application creates in this directory usually dont have read permissions for others.
i know there's something called... (3 Replies)
Hello,
I need to write a script to check directory size on a linux server.
I do not have access to some directories Inside the directory tree so I've got some warning in the output that say :
du : cannot read directory ....
Could you please help me. I did try Inside of my script to... (2 Replies)
Quick question,
is it possible to make a Tar of completely directory and placing the tar file in it (will this cause even the tar file to tarred ?)
sample:
/opt/freeware/bin/tar -cvf - /oracle | gzip > /oracle/backup.tgz
will the tar file backup.tgz also include backup.tgz ?
i tried... (5 Replies)
Discussion started by: filosophizer
5 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS --predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO bup-midx(1), bup-save(1)BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-margin(1)