|
Re: [Networker] hypothetical question
2011-01-20 17:02:32
Valere Binet wrote:
We rsync /nsr to one of our storage nodes, hoping we can "promote" it should
our server die.
Do you use the '-S, --sparse' options with rsync?
Valère
On Thu, Jan 20, 2011 at 2:15 PM, Tim Mooney <Tim.Mooney AT ndsu DOT edu> wrote:
In regard to: [Networker] hypothetical question, helenjay said (at
7:41am...:
If I tar'd the whole of /nsr and anything else related to networker,
could I use that backup to recover networker as opposed to mmrecov and
scanner etc., should I have a major disaster?
In the old, old days, the answer would likely have been "no", because many
versions of tar did not preserve sparse files and some of the db files had
the potential to be sparse.
These days, that's less of a concern. More versions of tar handle sparse
files, and the changes to the database formats have reduced or possibly
even eliminated the chance that any of the files will be sparse. You
don't say what platform you're on, so you'll want to check your version of
tar to make certain it does preserve sparse files, just in case.
We've tarred /nsr off to a safe location a few times in the past, with
NW shut down, but it didn't occur to me to use the 'sparse' option with
tar even though GNU tar does support it. However, I always created an
MD5 checksum listing of all of /nsr (recursive) before creating the tar
archive and then tested the archive by untarring it and validating all
the sums. I don't know if NW might use sparse files, but I guess it
couldn't hurt to include the option when using tar.
1. If NW does use sparse files, or did, what would happen if you didn't
include the option with tar? What's the worst case?
2. If you shut down NW, create MD5 checksums for all the files under
/nsr before tarring them, and then you create your tar file without the
'sparse' option, and you then untar the archive somewhere else and
validate all the checksums, and everything matches then is it safe to
say there are no sparse files?
If there were sparse files, and you didn't include the option with tar
then would you expect to see a mismatch on the MD5 sums for those files?
George
If the db files are quiescent (i.e. NetWorker shut down, or no checking
or updating going on for the files), a tar copy of them should be fine.
I wouldn't want it to be my only backup method, but it's a useful addition
to the standard bootstrap DR procedure.
Tim
--
Tim Mooney Tim.Mooney AT ndsu DOT
edu
Enterprise Computing & Infrastructure 701-231-1076 (Voice)
Room 242-J6, IACC Building 701-231-8541 (Fax)
North Dakota State University, Fargo, ND 58105-5164
To sign off this list, send email to listserv AT listserv.temple DOT edu and
type
"signoff networker" in the body of the email. Please write to
networker-request AT listserv.temple DOT edu if you have any problems with this
list. You can access the archives at
http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER
To sign off this list, send email to listserv AT listserv.temple DOT edu and type
"signoff networker" in the body of the email. Please write to networker-request
AT listserv.temple DOT edu if you have any problems with this list. You can access the
archives at http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER
--
George Sinclair
Voice: (301) 713-3284 x210
- The preceding message is personal and does not reflect any official or
unofficial position of the United States Department of Commerce -
- Any opinions expressed in this message are NOT those of the US Govt. -
To sign off this list, send email to listserv AT listserv.temple DOT edu and type
"signoff networker" in the body of the email. Please write to networker-request
AT listserv.temple DOT edu if you have any problems with this list. You can access the
archives at http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER
|
|
|
