Networker

Re: [Networker] any tips for backing up enormous sparse files?

2005-12-19 16:52:53
Subject: Re: [Networker] any tips for backing up enormous sparse files?
From: Tim Mooney <mooney AT DOGBERT.CC.NDSU.NODAK DOT EDU>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Mon, 19 Dec 2005 15:48:55 -0600
In regard to: Re: [Networker] any tips for backing up enormous sparse...:

These are holey files according to uasm ?

" holey
         The holey ASM handles holes or  blocks  of  zeros  when
         backing  up  files  and  preserves  these  holes during
         recovery.  On some filesystems interfaces can  be  used
         to  find  out  the  location  of file hole information.
         Otherwise, blocks of zeros that are read from the  file
         are skipped. This ASM is normally applied automatically
         and does not need not be specified."

It sounds to me like networker applies this directive automatically but
needs to read all the blocks of 0 but not transfer them.   Not sure what
the point is then.. Perhaps try specifying this directive anyway.

Thanks for pointing out this directive.  I didn't know about it.
I tried setting it explicitly, and it doesn't appear to have made any
difference.  I had other directives in the .nsr file that were noticed
and acted upon, so I believe my .nsr file was correct.

In this particular case, we can probably get by with running the "lastlog"
command, dumping the output to a file, and then skipping the real lastlog
file.  That works in this case, but won't work in general for large sparse
files.

Thanks,

Tim
--
Tim Mooney                              mooney AT dogbert.cc.ndsu.NoDak DOT edu
Information Technology Services         (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
wit 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