On 05/12/2013 06:20 AM, Edward Ned Harvey (lopser) wrote:
Without checking the internet, and before you listen to other peoples'
anecdotes or anything, I'd like to hear your gut feel, I want to know
what your natural instinct is. What do you think about the
reliability of the following tools?
If you have personal experience with them, obviously, that will shape
your perception. But even with no knowledge or experience with a
particular tool, I still want to know your instinct. Because your
preconceived notions influence decisions you make, give you bias in
terms of what tools you even think about using or researching.
Focus on reliability. ;-)
How do you define reliability? I can think of a few definitions:
1. That the tool, given one or more paths, will process every file in
those paths without problems.
2. That the tool, given one or more paths, will clearly report any
problems it encounters processing files to the administrator.
The latter definition I think is more realistic than the former one,
particularly with large-scale backups.
rsync
I've never used this one for backups (aside from as part of rsnapshot).
It will certainly report problems if it encounters them, although it can
be hard to parse the output, and also to get all the dozens of options
right.
rsnapshot
I use this one at home for some of my backups. It certainly works well,
although like rsync it can be hard to track down exactly what caused a
failure.
rdiff-backup
tar
Obviously have used tar for backups (who hasn't?) but I think it's even
harder to track down failures with tar than it is with rsync.
amanda
Used this years ago at my last job for backups. The reliability of
amanda is dependent on the underlying tool that's used to perform
backups - IIRC it can use tar, dump, or cpio (there's likely more, but
it's been too long). As I recall, it would report failures on a
per-filesystem basis (at least for dump), and then you could dig deeper
in the logs to figure out the exact problems.
bacula
Any other tools that you'd like to mention, that you're likely to use
for backups
Follow-up question: Given that these are all free open source
packages, which are probably included with your "stable" OS
distribution, would you have bias to assume they're reliable, just
because of that?
In the case of lower-level tools like tar, cpio, and rsync, I have a
trust-but-verify approach if I were to write a backup solution around
them. I would create a directory tree representative of what I would
most likely be backing up, start a test backup, then mess with it to try
to generate errors (i.e. adding/deleting/changing files during the
backup) to see what it reports at the end.
For the tools built up around these lower-level tools (rsnapshot,
amanda), I think there's some expectation that they already do that.
Skylar
_______________________________________________
Tech mailing list
Tech@lists.lopsa.org
https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech
This list provided by the League of Professional System Administrators
http://lopsa.org/
