Re: How exactly does Amanda get access to files?
On Mon, 20 Sep 2004, Ivan Petrovich wrote:
> > Alternatively, you can back up the files on the NFS server instead of on the
> > client.
>
> I am not udnerstanding this.
>
> I have host A with files that I want to back up.
> I have host B which runs the amanda server as well as amanda client.
> Host A is HPUX machine and I couldn't get the Amanda HP client to
> compile, but host B is GNU/Linux and is happily running an Amanda
> client.
> So I export files from host A (the NFS server) and mount them on host
> B (the NFS client), and run amdump on host B (the Amanda client) to
> back up to host B (the Amanda server).
>
> So how is it that I can do it differently?
By backing them up on machine A (HP-UX). But apparently you've already tried
that...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [EMAIL PROTECTED]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Re: How exactly does Amanda get access to files?
[Don't top-post!] George Kelbley wrote: My experience is that this is much slower than directly to the amanda server, but I guess there would be a lot of variable from site to site. Geert Uytterhoeven wrote: Alternatively, you can back up the files on the NFS server instead of on the client. How can a client be faster than a server. Someone has to read the bytes from the disk. And it's the server that has to give those bytes to the client anyway. Running the amanda client on the NFS-server can benefit from software compression too, resulting in less bytes to transfer over the network. Unless you have a very slow server and very fast client, and need "best" compression (but that is rarely needed: 4 times much cpu use to gain a few percentage space at most). Are there other circumsances? -- Paul Bijnens, XplanationTel +32 16 397.511 Technologielaan 21 bus 2, B-3001 Leuven, BELGIUMFax +32 16 397.512 http://www.xplanation.com/ email: [EMAIL PROTECTED] *** * I think I've got the hang of it now: exit, ^D, ^C, ^\, ^Z, ^Q, F6, * * quit, ZZ, :q, :q!, M-Z, ^X^C, logoff, logout, close, bye, /bye, * * stop, end, F3, ~., ^]c, +++ ATH, disconnect, halt, abort, hangup, * * PF4, F20, ^X^X, :D::D, KJOB, F14-f-e, F8-e, kill -1 $$, shutdown, * * kill -9 1, Alt-F4, Ctrl-Alt-Del, AltGr-NumLock, Stop-A, ...* * ... "Are you sure?" ... YES ... Phew ... I'm out * ***
Re: How exactly does Amanda get access to files?
>
> Alternatively, you can back up the files on the NFS server instead of on the
> client.
>
> Gr{oetje,eeting}s,
>
> Geert
I am not udnerstanding this.
I have host A with files that I want to back up.
I have host B which runs the amanda server as well as amanda client.
Host A is HPUX machine and I couldn't get the Amanda HP client to
compile, but host B is GNU/Linux and is happily running an Amanda
client.
So I export files from host A (the NFS server) and mount them on host
B (the NFS client), and run amdump on host B (the Amanda client) to
back up to host B (the Amanda server).
So how is it that I can do it differently?
Thanks!
Ivan
Re: How exactly does Amanda get access to files?
My experience is that this is much slower than directly to the amanda
server, but I guess there would be a lot of variable from site to site.
Geert Uytterhoeven wrote:
On Mon, 20 Sep 2004, Ivan Petrovich wrote:
Thanks for the information. You folks answered my question about how
amanda has access to all files as root, and I believe you are right
about root squash. I will look at the NFS export to try to fix the
problem.
Alternatively, you can back up the files on the NFS server instead of on the
client.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [EMAIL PROTECTED]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
--
George Kelbley System Support Group
Computer Science Department University of New Mexico
505-277-6502Fax: 505-277-6927
Re: How exactly does Amanda get access to files?
On Mon, 20 Sep 2004, Ivan Petrovich wrote:
> Thanks for the information. You folks answered my question about how
> amanda has access to all files as root, and I believe you are right
> about root squash. I will look at the NFS export to try to fix the
> problem.
Alternatively, you can back up the files on the NFS server instead of on the
client.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [EMAIL PROTECTED]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Re: How exactly does Amanda get access to files?
Joshua, George, & Frank, Thanks for the information. You folks answered my question about how amanda has access to all files as root, and I believe you are right about root squash. I will look at the NFS export to try to fix the problem. Thanks a lot again! Ivan
Re: How exactly does Amanda get access to files?
--On Monday, September 20, 2004 08:56:39 -0500 Ivan Petrovich <[EMAIL PROTECTED]>
wrote:
> Howdy,
>
> Here's the problem:
> I mounted a remote file system on a GNU/Linux system using autofs, and
> amdump fails to back up some files on this file system due to
> "Permission denied." I verified that the files which give this error
> are those that have the 'read' permission bit turned off for 'others'.
>
> I thought about it and thought that it made sense that 'amdump'
> wouldn't be able to read it since it runs as 'amanda', and not root.
>
> But how is it that amdump is able to read all files in all other file
> systems (as if it were root), including local file systems and
> NFS-mounted (non-autofs) file systems? Though 'Amanda' user is in the
> 'disk' group, but when amanda runs using 'gtar', it does not read the
> raw device ("/dev/???"), so having group access to the raw devices
> shouldn't help, right?
>
> Besides, it has no problem reading the NFS-mounted (non-autofs) file
> systems either, and NFS-mounted volumes are not owned by group 'disk'.
>
> So my questions are:
> 1. How exactly does Amanda's client get read access to all files that
> it dumps when it uses 'gtar'?
gtar is called by the runtar wrapper, which is suid root.
> 2. Does any one know why it couldn't read all files on an auto-mounted
> file system?
Your export of the filesystem is evidently mapping root to nobody, so
Amanda can't read all the files.
Depending on the OS on the fileserver, look for options like root= or
no_root_squash to enable root on the client to be treated as root on
the fileserver.
Frank
>
> Thanks in advance!
>
> Ivan
>
--
Frank Smith [EMAIL PROTECTED]
Sr. Systems Administrator Voice: 512-374-4673
Hoover's Online Fax: 512-374-4501
Re: How exactly does Amanda get access to files?
On Mon, 20 Sep 2004 at 8:56am, Ivan Petrovich wrote > Here's the problem: > I mounted a remote file system on a GNU/Linux system using autofs, and > amdump fails to back up some files on this file system due to > "Permission denied." I verified that the files which give this error > are those that have the 'read' permission bit turned off for 'others'. *snip* > So my questions are: > 1. How exactly does Amanda's client get read access to all files that > it dumps when it uses 'gtar'? When using tar, amanda executes it via the setuid root 'runtar' script. So, tar is run as root. > 2. Does any one know why it couldn't read all files on an auto-mounted > file system? At a guess, the default NFS export option (at least on Linux) is to map root (from clients) to nobody (on the server). I'd guess that that is what's going on. -- Joshua Baker-LePain Department of Biomedical Engineering Duke University
How exactly does Amanda get access to files?
Howdy,
Here's the problem:
I mounted a remote file system on a GNU/Linux system using autofs, and
amdump fails to back up some files on this file system due to
"Permission denied." I verified that the files which give this error
are those that have the 'read' permission bit turned off for 'others'.
I thought about it and thought that it made sense that 'amdump'
wouldn't be able to read it since it runs as 'amanda', and not root.
But how is it that amdump is able to read all files in all other file
systems (as if it were root), including local file systems and
NFS-mounted (non-autofs) file systems? Though 'Amanda' user is in the
'disk' group, but when amanda runs using 'gtar', it does not read the
raw device ("/dev/???"), so having group access to the raw devices
shouldn't help, right?
Besides, it has no problem reading the NFS-mounted (non-autofs) file
systems either, and NFS-mounted volumes are not owned by group 'disk'.
So my questions are:
1. How exactly does Amanda's client get read access to all files that
it dumps when it uses 'gtar'?
2. Does any one know why it couldn't read all files on an auto-mounted
file system?
Thanks in advance!
Ivan
