Date: Mon, 29 Mar 2004 22:11:51 +0200 From: Christoph Sold <cs@cheasy.de> To: freebsd-isp@freebsd.org, sellis@telus.net Subject: Re: tape backup from remote Message-ID: <200403292211.58942.cs@cheasy.de> In-Reply-To: <20040329183323.GC51870@telus.net> References: <20040329183323.GC51870@telus.net>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Monday 29 March 2004 20:33, Sean Ellis wrote: > Hello, G'day, > I have a very general question about backing up to tape from a remote > computer. The tape drive is unfamiliar territory for me, and I'm > looking for recommendations for a sequence of steps to take. Wise decision. > Both machines are running fbsd 4.*, the local machine is a recent 4.9 > STABLE, and the tape drive is a Conner CTD800R-S. Will it be > possible, or advisable, to use a utility to back up over the net > directly to the tape, or should we be creating a local mirror and > backing up this? Backing up remotely can yield _very_ unsatisfying results for several reasons: - - If there is not enough bandwith, the tape "trashes": After backing up a few blocks, the tape has to stop, rewind, then re-synchronize and append to the previously written data. This is _much_ slower than nominal backup speed. - - If the network latency is too high, the backup software may get confused and abort. - - If the connection is dropped during backup, may tools invalidate the whole backup. There are both commercial as well as open source tools dealing with this situation. I used amanda (in the ports) to backup multiple remote clients to one backup machine. Never experienced any data loss during restore. > I know that these are very basic questions, but I felt that posting > here in isp might give me a more informed response. Have a look at http://www.thestoragegroup.com/pubs.html , the links there show many aspects of backup and recovery. Another hint, though: DDS (DAT) is not up to the job. I personally ditched all DDS devices after multiple data loss events being caused by worn tapes, never properly written tapes, over-aged tapes. Never happend with DLT, though. HTH - -Christoph Sold -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFAaIMHjGVuYEZ1RPYRAuy+AJ473q/Q5JXWodJu3aeO1y3pQVFT7wCfUkAr kOiW2k50MoiflSIxUO46+KE= =tPFi -----END PGP SIGNATURE-----
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