[rdiff-backup-users] rdiff-backup versus rsnapshot

2008-04-28 Thread Richard Chapman

Hi

I am planning a holistic backup system for a mixed windows/linux 
network. The system should provide for both disaster recovery and 
accidental deletion protection.


It appears to me that both rdiff-backup and rsnapshot would do a good 
job for me. Could anyone provide their thoughts on the relative 
strengths and weaknesses of the two tools.


I have posted a similar request on the rsnapshot list - and have had 
some response suggesting that rdiff-backup will need less storage - but 
may be slower with a lot of changing data. Also - that recovering 
specific files at specific ages may be easier with rsnapshot.


Looking at the rdiff-backup documentation - it appears to me that 
rdiff-backup stores the change data indefinitely. If this is so - and 
there is no way to delete old data - I assume the historical change 
data will grow indefinitely. Is this the case - or have I missed something?


I would value the opinions of users of this group also.

Regards

Richard.







___
rdiff-backup-users mailing list at rdiff-backup-users@nongnu.org
http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users
Wiki URL: http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki


Re: [rdiff-backup-users] rdiff-backup versus rsnapshot

2008-04-28 Thread Patrick Nagel
Hi Richard,

Richard Chapman (Tuesday, 2008-04-29):
 It appears to me that both rdiff-backup and rsnapshot would do a good
 job for me. Could anyone provide their thoughts on the relative
 strengths and weaknesses of the two tools.

 I have posted a similar request on the rsnapshot list - and have had
 some response suggesting that rdiff-backup will need less storage - but
 may be slower with a lot of changing data. Also - that recovering
 specific files at specific ages may be easier with rsnapshot.

I can't say anthing to that, because I don't know rsnapshot. But...

 Looking at the rdiff-backup documentation - it appears to me that
 rdiff-backup stores the change data indefinitely. If this is so - and
 there is no way to delete old data - I assume the historical change
 data will grow indefinitely. Is this the case - or have I missed
 something?

... there you missed the --remove-older-than option.

Patrick.

-- 
Key ID: 0x86E346D4http://patrick-nagel.net/key.asc
Fingerprint: 7745 E1BE FA8B FBAD 76AB 2BFC C981 E686 86E3 46D4


signature.asc
Description: This is a digitally signed message part.
___
rdiff-backup-users mailing list at rdiff-backup-users@nongnu.org
http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users
Wiki URL: http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki

Re: [rdiff-backup-users] rdiff-backup versus rsnapshot

2008-04-28 Thread Mike Marseglia
A quick google turned up the following from
http://www.backupcentral.com/components/com_mambowiki/index.php/Rdiff-backup:

Advantages

Here are some advantages of using rdiff-backup instead of an rsync script
or rsnapshot.

Backup size

Because rdiff-backup does not store complete copies of older files,
but only the compressed differences between older and current files,
backups generally consume less disk space.

Easier-to-use

Unlike rsync, rdiff-backup was written originally for backups. It has
sensible defaults (so no need for the -av –-delete -e ssh options) and
fewer quirks (for instance, no distinction between destination,
destination/, and destination/.).

Preserves all information

With rsync, all information is stored in the filesystem itself. If you
log into your backup repository as a non-root user (generally a good
idea), the rsync method forgets who owns all your files! rdiff-backup
keeps a copy of all metadata in a separate file, so no information is
lost, even if you aren’t root or if you back up to a different kind of
filesystem.

[edit]
Handy backup features

rdiff-backup has several miscellaneous handy features. For example, it
keeps detailed logs on what is changing and has commands to process those
logs so that you know which files are using up your space and time. Also,
newer versions keep SHA-1 checksums of all files so you can verify the
integrity of backups. Some rsync scripts have similar features—check their
documentation.
[edit]
Disadvantages

Let’s be honest: rdiff-backup has some disadvantages too:

Speed

rdiff-backup consumes more CPU than rsync and is therefore slower than
most rsync scripts. This difference is often not noticeable when the
bottleneck is the network or a disk drive but can be significant for
local backups.

Transparency

With rsync scripts, all past backups appear as copies and are thus
easy to verify, restore, and delete. With rdiff-backup, only the
current backup appears as a true copy. (Earlier backups are stored as
compressed deltas.)

Requirements

rdiff-backup is written in Python and requires the librsync library.
Unless you use a distribution that includes rdiff-backup (most of them
include it), installation could entail downloading and installing
other files.

-- 
Mike Marseglia
[EMAIL PROTECTED]
http://www.marseglia.org

On Mon, April 28, 2008 12:02 pm, Richard Chapman wrote:
 Hi

 I am planning a holistic backup system for a mixed windows/linux
 network. The system should provide for both disaster recovery and
 accidental deletion protection.

 It appears to me that both rdiff-backup and rsnapshot would do a good
 job for me. Could anyone provide their thoughts on the relative
 strengths and weaknesses of the two tools.

 I have posted a similar request on the rsnapshot list - and have had
 some response suggesting that rdiff-backup will need less storage - but
 may be slower with a lot of changing data. Also - that recovering
 specific files at specific ages may be easier with rsnapshot.

 Looking at the rdiff-backup documentation - it appears to me that
 rdiff-backup stores the change data indefinitely. If this is so - and
 there is no way to delete old data - I assume the historical change
 data will grow indefinitely. Is this the case - or have I missed
 something?

 I would value the opinions of users of this group also.

 Regards

 Richard.







 ___
 rdiff-backup-users mailing list at rdiff-backup-users@nongnu.org
 http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users
 Wiki URL:
 http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki





___
rdiff-backup-users mailing list at rdiff-backup-users@nongnu.org
http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users
Wiki URL: http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki


Re: [rdiff-backup-users] rdiff-backup versus rsnapshot

2008-04-28 Thread Chris Wilson
Hi all,

On Mon, 28 Apr 2008, Mike Marseglia wrote:

 A quick google turned up the following from
 http://www.backupcentral.com/components/com_mambowiki/index.php/Rdiff-backup:
...
 Disadvantages
 
 Let’s be honest: rdiff-backup has some disadvantages too:
 
 Speed
 
 rdiff-backup consumes more CPU than rsync and is therefore slower than
 most rsync scripts. This difference is often not noticeable when the
 bottleneck is the network or a disk drive but can be significant for
 local backups.

I would add the following:

rdiff-backup uses a lot more network bandwidth than rsync. About 1GB per 
100GB covered per backup, in my estimate, in addition to the deltas. This 
makes it too slow for us to use for daily offsite backups (uploading over 
a 384kbit DSL, backing up about 500GB daily).

rdiff-backup is a bit fragile. It's easy to corrupt the metadata, for 
example if the store disk gets full, or multiple backups run to the same 
destination at the same time, and usually impossible (i.e. nobody knows 
how) to recover the history after that happens.

rdiff-backup does not allow one to remove an intermediate increment (for 
example if a large file accidentally got backed up that shouldn't be) or 
to remove a subtree of the backup (at least not without risking metadata 
corruption again).

 With rsync scripts, all past backups appear as copies and are thus 
 easy to verify, restore, and delete. With rdiff-backup, only the current 
 backup appears as a true copy. (Earlier backups are stored as compressed 
 deltas.)

For me, this is a mixed blessing. Large numbers of small files take a lot 
of space on the remote server (as with rsync too), and you can trash your 
backup by accidentally modifying files in the remote repository. But it 
has been useful in emergency recovery situations where I have had to boot 
from a recovery CD that didn't have rdiff-backup on it.

I do like rdiff-backup and I use it extensively, but these are things that 
I wish for that would make it even better.

Cheers, Chris.
-- 
_ __ _
\  __/ / ,__(_)_  | Chris Wilson  at qwirx.com - Cambs UK |
/ (_/ ,\/ _/ /_ \ | Security/C/C++/Java/Ruby/Perl/SQL Developer |
\ _/_/_/_//_/___/ | We are GNU : free your mind  your software |___
rdiff-backup-users mailing list at rdiff-backup-users@nongnu.org
http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users
Wiki URL: http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki