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From: nieusma@cs.colorado.edu (Jeff Nieusma)
Newsgroups: comp.unix.questions,comp.unix.programmer,alt.sys.sun
Subject: Re: Source for dump/restore/rdump/rrestore?
Keywords: dumping via NFS
Message-ID: <1991Jan24.205439.20425@csn.org>
Date: 24 Jan 91 20:54:39 GMT
References: <1991Jan23.201918.5649@javelin.es.com> <1991Jan23.213346.1874@Think.COM>
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Reply-To: nieusma@cs.colorado.edu (Jeff Nieusma)
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In article <1991Jan23.213346.1874@Think.COM>, barmar@think.com (Barry
Margolin) writes:
|> Note that the design of dump makes it very difficult to extend to
|> NFS-mounted directories, so you should plan on extending rdump to
|> support
|> the 3480 drive (this probably just involves recognizing the
|> device-specific
|> status flags).  It accesses the partition through the raw disk
|> device, not
|> through the file system system calls, but the NFS protocol only
|> supports
|> file system operations.  If you want to be able to dump NFS-mounted
|> file
|> systems you can use utilities such as tar (GNU tar includes some
|> options
|> that are intended to support its use within a backup system) or
|> other
|> 3rd-party backup utilities.

You really don't want to dump an NFS mounted file system.  It doesn't matter 
how fast you make your program, it will never be faster than reading the raw
disk partition and sending it to a remote host via tcp or streams.  There is
a ton of overhead that cannot be bypassed when using NFS.

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