Hi, My account is : abcd
I belong to a group: pqrs
Some thing straneg happened yesterday.
My .cshrc and .login got overwritten into pqrs's .cshrc and .login
I obviously did not explicitly overwrite pqrs's .cshrc.
Are there any reasons how this could have happened indirectly due to... (5 Replies)
Hello,
One of my frend had a problem.
He had Windows XP installed on his system. Then he installed Red Hat Linux 8.0 in one of the partitions. After some time his XP got corrupt and then he reinstalled Windows XP. This over wrote the Grub loader entry, and due to this the grub loader is not... (2 Replies)
We have a problem where we delete a user and their associated UID gets dumped back in the UID pool. The if we immediately create a another (new) user, AIX reuses the last UID, the one that was just released. This is causing a problem when reports are being generated because the new users name is... (2 Replies)
Due to my own stupidity I managed to overwrite my /dev/root device using dd (don't ask).
Current state is
- Have current backup created using cpio (command used was 'find . -mount -depth -print|cpio -ocB > $TAPE')
- Once I realised what was happening powered off the server but this was too... (2 Replies)
The following files were wiped out - new empty files were left in their place.
/etc/inittab, /etc/inetd.conf, and /etc/MANPATH
The system is running HP-UX 11i v3 - Mar08.
Anyone seen anything like this?
Any ideas on a way to figure this out if it happens again or a suggested way to... (9 Replies)
Hey peeps,
Here is somethin u might find interestin....
Is it possible to recover data from a partition which used to be an ext3 file sytem with some nice forgotten backups, which now is an lvm partion containg root partition of another OS. :)
I couldn't create any mess better than this, can... (2 Replies)
Hi,
The dump device on my system was set to /dev/dsk/c0t0d0s7. I have done a savecore -Lv on the system which worked fine. I'm wondering have I overwritten the rootdisk here by mistake? The system is still up but will need to be rebooted due to an error on it. Will it come back up?
... (8 Replies)
Hello All,
I am writing a bash script on Solaris O/S. I looping through an array. For each iteration, i connect to the datatabase and use select statement. Output of which is redirected to .CSV file. here is the code for it.
output="loop.csv"
elements=${#currency_pair}
... (3 Replies)
Hi All,
I am new new to unix.com, I have a question related to shell scripting.
We have a Oracle database backup shell script, which can be used for taking full, incremental & archive log backup based on the parameters passed.
Within the script we export a variable as
export... (5 Replies)
I had generated a ssh2 key on my AIX box, to receive files from other AIX and Linux systems.
Key Name: id_ssh2_server.pub
However this ssh2 key (both public and private keys) has been overwritten, while I was generating another ssh2 key. Now the earlier configured target systems are not able... (3 Replies)
Discussion started by: freakygs
3 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)