[9fans] p9p vbackup on linux

[9fans] p9p vbackup on linux

[John Soros]

Hello, I am trying to set up a vbackup system on a linux machine. I am having problems mounting the nfs service. Here is how i am doing it:
(the venti server works fine, for sure, and vbackup worked, as vftp can see the files)
$ venti='tcp!venti!venti' vbackup /dev/sda6
mount /dazone/2008/0623/mnt/other ext2:7610bd359effdec12fb1b4dfbe76d01b84dc61b8 2008/0623/1716
# 2008/0623 17:16:20.164 /dev/sda6 ext2:7610bd359effdec12fb1b4dfbe76d01b84dc61b8
$ venti='tcp!venti!venti' vnfs vnfs.conf
handle XXXXXXXXXX
$ vmount 'udp!loclahost!2049' /mnt/dump
mount: can't get address for udp!127.0.0.1!2049
$ vmount localhost /mnt/dump
mount: mount to NFS server 'localhost' failed: RPC Error: Program unavailable.

If anyone has had more luck with this, a little help would be greatly appreciated!
Thanks
John

Re: [9fans] p9p vbackup on linux

[a]

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Something of a recap from irc, but for others who might be interested:

On OS X, this all just worked for me pretty much as described in the
manual. With a running venti and $venti set, I ran this:
	sudo vbackup /dev/rdisk0s2
and a few hours later got output like this:
	mount /vav/2008/0624 hfs:35eb...5a1b 2008/0624/1447
	# 2008/0624 14:47:07.178 /dev/rdisk0s2 hfs:35eb...5a1b
Adding those lines verbatim to a file 'config', I then ran:
	vnfs -c 16k config
and got back:
	handle da...0d
I don't yet fully understand the implications of that 16 char hex string,
so I'm not posting it here, but I didn't seem to need it anywhere else.
I'd previously created /mnt/dump, and then
	sudo vmount udp!localhost!2049 /mnt/dump
made paths like /mnt/dump/vav/2008/0624/Users/anthony exist.

On my venti server, I got a *lot* of these messages:
	venti/venti: bucket overflow XXX
but I think I understand that (this is a junk venti server used for
experimentation, so i didn't spend any time sizing things appropriately)
and it's unrelated to vbackup or vnfs. The only real problem from just
following the manual exactly was the instructions to mount something
like udp!localhost!nfs; my system couldn't resolve "nfs", so I pulled the
port number out of my local /etc/services and all was well.

Notes:
1)	This is really nice. Once I sort out issue #2 below and get a cron
script together, I've got my new cross-platform network backup system.

2)	vbackup from another host didn't work. Both are reasonably recent
p9p installs (the "other" system is from yesterday, and my venti server
is from a month or two ago), but i get:
	vbackup: vtconnect: vtversion: bad format in version string
I'll look into it more in any time I get while traveling.

3)	Speed isn't stellar, but is okay. Every compressed audio or video
file I tried worked without issue, but raw 640x480 DV was a bit much
for it. Mind you, that's with everything on one system and the venti
arenas on a HFS+ file system on an external FireWire 400 disk.

4)	It looks like libdiskfs allows vnfs to serve up arbitrary disk image
formats (hfs, ffs, ufs, &c), which is awesome, but it'd be nice if it could
also serve vac snapshots. Anything peculiar about vac that inhibits this,
or is it just a matter of extra code in libdiskfs (or in vnfs, to switch
between libdiskfs and something for vac)?

5)	I didn't do anything particular regarding a portmapper and have
never run nfs on this Mac, but ps does show I've got /usr/sbin/portmap
running. Maybe another small datapoint for John's problem.

Anthony

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From: John Soros <sorosj@gmail.com>
To: 9fans@9fans.net
Subject: [9fans] p9p vbackup on linux
Date: Wed, 25 Jun 2008 12:22:36 +0200
Message-ID: <20080625122236.59debc5d@dazone>

Hello, I am trying to set up a vbackup system on a linux machine. I am having problems mounting the nfs service. Here is how i am doing it:
(the venti server works fine, for sure, and vbackup worked, as vftp can see the files)
$ venti='tcp!venti!venti' vbackup /dev/sda6
mount /dazone/2008/0623/mnt/other ext2:7610bd359effdec12fb1b4dfbe76d01b84dc61b8 2008/0623/1716
# 2008/0623 17:16:20.164 /dev/sda6 ext2:7610bd359effdec12fb1b4dfbe76d01b84dc61b8
$ venti='tcp!venti!venti' vnfs vnfs.conf
handle XXXXXXXXXX
$ vmount 'udp!loclahost!2049' /mnt/dump
mount: can't get address for udp!127.0.0.1!2049
$ vmount localhost /mnt/dump
mount: mount to NFS server 'localhost' failed: RPC Error: Program unavailable.

If anyone has had more luck with this, a little help would be greatly appreciated!
Thanks
John

Re: [9fans] p9p vbackup on linux

[Russ Cox]

> Adding those lines verbatim to a file 'config', I then ran:
> 	vnfs -c 16k config
> and got back:
> 	handle da...0d
> I don't yet fully understand the implications of that 16 char hex string,
> so I'm not posting it here, but I didn't seem to need it anywhere else.

It was just a debugging print.  It's the root handle that
clients need to know to connect to the NFS server.
It used to be randomly generated each time vnfs started,
but I found it was much easier to use a fixed one.
The bytes you didn't post are the first 8 bytes of
sha1sum /dev/zero.

> On my venti server, I got a *lot* of these messages:
> 	venti/venti: bucket overflow XXX
> but I think I understand that (this is a junk venti server used for
> experimentation, so i didn't spend any time sizing things appropriately)

Right, your index is too small.

> 4)	It looks like libdiskfs allows vnfs to serve up arbitrary disk image
> formats (hfs, ffs, ufs, &c), which is awesome, but it'd be nice if it could
> also serve vac snapshots. Anything peculiar about vac that inhibits this,
> or is it just a matter of extra code in libdiskfs (or in vnfs, to switch
> between libdiskfs and something for vac)?

Better to just use vacfs -m if you want to view vac,
and skip NFS entirely.  NFS doesn't let you see
close events, so you have to make up handles
that can last an arbitrarily long time.  This is pretty
easy if you're serving a fixed set of Unix file system
disk images: the handle specifies the particular disk
image and  the inode in that disk image.  There's no
similarly easy handle to use for vac archives.
(Also remember that the handle has to have enough
information to make dotdot work!)

Also, vac -a is a viable alternative to vbackup, and
it lets you exclude certain directories or files from
the backup.

Russ

Re: [9fans] p9p vbackup on linux

[a]

// The bytes you didn't post are the first 8 bytes of
// sha1sum /dev/zero.

Hey! How do you know what's in my /dev/zero?

// Better to just use vacfs -m if you want to view vac,
// and skip NFS entirely.

To the extent that I just (or primarialy) want to see vac
dumps, sure. The idea was having a single location for
the variety of image types. Also, doing so with NFS
allows me to do it on a wide variety of Unix hosts with
no modifications or even installed software.

Of course, having played with it for a few days now,
I'll likely just end up doing vac dumps anyway. -a just
makes it that much more compelling.
Anthony