Date: Mon, 29 May 2000 23:06:51 -0700 (PDT) From: <keith@mail.telestream.com> To: Victor Sudakov <sudakov@sibptus.tomsk.ru> Cc: questions@FreeBSD.ORG Subject: Re: Anyone using dump(8) Message-ID: <Pine.LNX.4.10.10005292244240.27088-100000@mail.telestream.com> In-Reply-To: <200005300141.e4U1faK17051@sibptus.tomsk.ru>
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I use dump every day. Seeing that I had a million of my questions answered from the list not to long ago I'll repay the debt on your questions. :) #1 If file systems are to be mouted read only durring a dump then it's news to me. I've never heard of it and have never done it. A quick look at the man page for dump doesn't say this either. #2 I use dump for 5 servers on my network to a single machine. Works realy good. You have to allow for rsh because dump will use it to do the dirty work. Not exactly secure but if you aren't doing dumps in a cron script then you can just enable rsh durring the times you prefer to do the dumps. #3 You don't have to be single user to do a dump. That would kind of defeat the use of a network dump. #4 I'm not entirely sure about this but as far as doing a dump on an active file system. Dump takes a sort of snapshot of the file system before it starts pumping data to tape. So files modified durring a dump will only have the data as it was before dump took the snap of it. As soon as you issue the dump command your disks will go crazy as dump figures out what all needs to be dumped. I just kind of assumed <ouch> that it was snaping the file system. Or depending on the level of dump you are doing will be looking to see the modification dates on files to determine what needs dumping. Anyone with more info on this I'd like to know about it. #5 I've never known anyone to halt services while dumping a file system. Hope that answered some questions. Keith ================================= Keith W. At the helm <for better or worse> ================================= On Tue, 30 May 2000, Victor Sudakov wrote: > Hello. > > I wonder if anyone uses dump(8) nowadays in a production environment. > It seems the best backup tool as it preserves hard links, sparce files > etc. However, there are some practical questions I need enlightment > on. > > 1. You are supposed to mount a filesystem readonly before you dump it, > right? Then dump cannot write /etc/dumpdates and aborts. Moreover, I > cannot stop the services every time I need to dump a filesystem. How > do you deal with that? > > 2. The tape drive is only on one host, so I need to dump filesystems > over the network. I can boot in single user mode, mount the > filesystems readonly, but then I have to do all the ifconfig, route > etc. stuff (to see the tape server) by hand which is annoying. > > 3. Is dump really so vulnerable to modifications of filesystems during > dump? Then how is it supposed to work on non-stop systems? > > Surely there must be some know-how. People seem to have been using > dump(8) for years, and in huge companies too. I only have to dump 11 > boxes, some with very important data updated every 20 minutes or so, > to a tape drive on one of the boxes. Dump users, please reply. > > Any input is greatly appreciated. > > -- > Victor Sudakov, VAS4-RIPE, VAS47-RIPN > 2:5005/149@fidonet http://vas.tomsk.ru/ > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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