Remote dumps

[Doug Hardie]

I have a number of servers, some of which are difficult to physically access. I wanted to put a large drive on one and then do dumps of the other machines to it. I don't seem to have everything setup properly, as it is not working.

The backup drive is attached to the machine named "master". The machine I am trying to dump is "mail". I started out by testing dumping master first. The command:

master# nohup dump -h0 -0aLf/dumps/master.dump / &

works. I get a dump on the drive. In the process of trying to figure out why remote dumps were not working, I tried:

master# nohup dump -h0 -0aLf root@master:/dumps/master.dump / &
[1] 20446
master# DUMP: master: Connection refused
DUMP: login to master as root failed.

That doesn't seem to make any since. Both dumps are run as root. Somehow the login process is not functioning properly. How do I track down that problem? When I try to run dump on mail, I get a similar error:

mail# dump -h0 -0aLf root@master:/dumps/mail.dump /
DUMP: master: Connection refused
DUMP: login to master as root failed.

auth.log on both machines show no entries around that time.

-- Doug

[Matthias Petermann]

Hello,

Not sure how FreeBSD differs from NetBSD in this regard, but I ran into a similar situation and ended up using something like this:

    $ ssh backup@remote-machine /sbin/dump -X -h 0 -b 64 -0auf - /filesystem-to-dump > local-dumpfile.dump

In this setup, the backup host (with the large disk attached) connects to the remote machine via SSH and invokes dump there. The command forces dump to write its output to stdout (-f -), which is then streamed back over SSH. Locally, I simply redirect that stream into the actual dump file. 

Best regards

Matthias

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[John Levine]

It appears that Doug Hardie <bc...@lafn.org> said:
>master# DUMP: master: Connection refused
> DUMP: login to master as root failed.
>
>That doesn't seem to make any since. Both dumps are run as root. Somehow the login process is not functioning properly. How do I
>track down that problem? When I try to run dump on mail, I get a similar error:

That's not surprising. As the dump man page says, if you use user@host:file
syntax, it runs the antique rmt program which probably doesn't do what you
want.

The easiest approach is to mount the dump volume with NFS, and dump
to it that way. Be sure to set -maproot to something reasonable in the
exports file.

Or something like this:

dump -h0 -0aLf - / | ssh master "dd of=/dumps/mail.dump"

R's,
John

[Doug Hardie]

That is a neat approach. It works jusf fine on FreeBSD. Thanks.

-- Doug