My Gentoo diskless install howto

kucrut · n00b Joined: 24 Jun 2005 Posts: 38

First off, thanks for the original howto, as well as pdf howto from wimalopaan. one thing left tho, does the client use server's resources or does it use its own?

wimalopaan · n00b Joined: 06 Jul 2005 Posts: 15

If you have only one client-configuration, all is well with my description in

http://mozart.informatik.fh-kl.de/download/Software/GentooDiskless/diskless2_en.pdf

But if have several groups of clients with slightly different configurations it is wasteful, if you use a different full client-root. It would be much easier if we could use filesystem unification. This can be done by unionfs

http://www.fsl.cs.sunysb.edu/project-unionfs.html

but there are some issues on using unionfs over nfs on unionfs. I wrote a patch for the actual unionfs-cvs-snapshot to overcome this limitation.

The patch disables the lookup of whiteouts in the right-most branch and
disables the lookup of whiteouts in ro-branches before the check if the
whiteout must be renamed. You can't use unionfs directly as an underlying fs
for unionfs, but you can use a nfs-exported unionfs-filesystem as a
ro-branch. Now, unionfs sees a nfs-branch, which is allowed, and the unneeded
lookups aren't done anymore. This was a major drawback, because the
whiteout-lookup in the ro-branches causes the underlying unionfs to return an
'Operation not permitted'. With the patch, this doesn't happen anymore.

This problem is typical in the case of diskless-clients with different
configurations. In this scenario you have a base client-root-directory
(say /tftproot/client_A) and some derived client-roots
(e.g. /tftproot/client_B), which are something like

/tftproot/client_B dirs=/tftproot/client_Bdiff=rw:/tftproot/client_A=ro.

These /tftproot/client_* can be ro-exported via nfs. On the client-side you
can use them as a rightmost ro-branch for the client-root and the other
branches tmpfs, e.g.

mount -t tmpfs none /tmpfs/etc
mount -t unionfs none /etc -o dirs=/tmpfs/etc=rw:/etc=ro

We found this very useful in our environment.

wimalopaan · n00b Joined: 06 Jul 2005 Posts: 15

Sorry, but the link to the patch wasn't included in my previous posting:

http://mozart.informatik.fh-kl.de/download/Software/GentooDiskless/gdxs.html

kyron · Posted: Mon Jan 16, 2006 2:46 pm Post subject:

First, obvious thanks go to wimalopaan for his document.

I jsut wanted to tell you all that I am trying to sum up a wiki version of this document. I wrote an e-mail to wimalopaan for explicit permission to do so. As I stated in my e-mail, I am only using my personnal wiki as a "sandbox" before posting a more complete version of the document on the (non-) official Gentoo Wiki

My motives for wikifying the document:
1- easy update
2- easy copy-paste of scripts
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simon78 · n00b Joined: 02 Feb 2004 Posts: 52

Thanks for the howto! I installed a mythfrontend using this guide a year or so ago. I updated the server (dhcp/nfs/tftp) to the new baselayout and udev. Now it seems like tftp doesn't work. The diskless recieves its IP from dhcp:

kyron · Posted: Wed Jan 25, 2006 12:32 pm Post subject:

BonesToo · Apprentice Joined: 19 Aug 2003 Posts: 153

I've been running a diskless gentoo client now for 2 months with help from this thread and the diskless doc on gentoo.org. All is running good. Although I have one issue that I haven't worked out yet and I can't seem to find an answer for it anywhere.

When I reboot/shutdown the machine with "reboot", "shutdown -h now", or "halt" everything shuts down correctly except at the very end of the process my hardware is still running. It never actually powers off or reboots to the bios, it just waits with the following text on the screen:

kyron · Posted: Tue Mar 07, 2006 10:03 am Post subject:

BonesToo · Apprentice Joined: 19 Aug 2003 Posts: 153

I'll try changing script to /sbin/poweroff -f. But I don't know how this will be any different.

You bring up a good point. Using a ramfs to store the files needed during the shutdown process. This is what I've been spending most of my time on. But I am having trouble getting my initramfs cpio image compiled into the kernel. I followed gentoo doc instructions and did the following:

1) Copied my initramfs cpio compressed image to /usr/src/linux/usr/initramfs_data.cpio.gz

2) execute: touch /usr/src/linux/usr/initramfs_data.cpio.gz

3) make the kernel as normal

But it still seems to make a new cpio image from the initramfs_list. Any help here? I'm going to look around on the forums for more info on this.

Per Olav · n00b Joined: 15 Sep 2004 Posts: 42 Location: Norway

emuller · n00b Joined: 28 Oct 2005 Posts: 23

kyron · Posted: Sat Apr 08, 2006 3:44 pm Post subject:

FYI, there is some work being done specifically for the NFS root mount/unmount issues:
https://bugs.gentoo.org/show_bug.cgi?id=99682
And the following is also interesting:
https://bugs.gentoo.org/show_bug.cgi?id=112059
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wimalopaan · n00b Joined: 06 Jul 2005 Posts: 15

Hi,

for anyone who is interested:

as described in a previous posting our diskless setup includes the use of unionfs on the client and on the server. On the server we can then maintain relatively simple a set of diskless client roots for different purposes, e.g. one setup for a diskless rich client (the user logs into the client and the KDE-session starts on the client) and one setup for a diskless thin client (the user logs into the server and the KDE-session starts on the server), and so on.

Especially if you have diskless thin clients it is neccessary to transport the local devices of the thin client to the server. We experimented with several solutions (nfs back to the server, samba, ...) but we came up with the adoption of the LTSP solution what is called ltsp-fs.

We provide ebuilds for the ltsp-fs and some (little) documentation on

http://mozart.informatik.fh-kl.de/download/Software/GentooDiskless/gdxs.html

and

http://mozart.informatik.fh-kl.de/download/Software/GentooDiskless/ltspfs.html

Please note that you need to use the provided overlay ebuild for pmount as well (mainly for security reasons). Also note that you have to setup two kde autostart scripts as described in the output of the ebuilds.

wescott · Posted: Tue Jul 25, 2006 1:09 pm Post subject:

Thanks for the howto. This would work great for the set-top boxes I want to develop (for expandability, extra boxes that boot this way).
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cloc3 · Posted: Wed Nov 08, 2006 1:41 pm Post subject: Re: Diskless Gentoo Client

petrasl · n00b Joined: 18 May 2004 Posts: 69 Location: Swiss

Hi,

I'm trying to setup Gentoo on a diskless laptop following the wiki, but I have some trouble:

The server is ready and the laptop boot on « pxe » mode ; the grub's menu is printed.
The image of the kernel is loaded, but the system hangs when once the kernel gives the hand to « init ».

With the last kernel's log, I see that the interface « eth0 » is ready and has the good settings: IP / rootserver / rootpath
- The nfs root file system is mounted correctly
- devfs is mounted on /dev (kernel-2.4)
- INIT: version 2.86 booting

This is part of my kernel configuration:

erik258

I am doing the same install method. All seems to go OK at boot, until

mikek · n00b Joined: 28 Dec 2003 Posts: 8

erik258 · Posted: Mon Dec 25, 2006 4:50 am Post subject:

I think i may have had a similar problem. i will try to help if you like; i'd like to see the kernel boot command line and the last line on the screen, though. My guess would be that either the mount is failing but thinks its succeeding or succeeds but the directory is specified incorrectly and there isn't a system rooted there, or perhaps you forgot to add support for root fs on nfs? I wanted to quote menuconfig to help you out but couldn't find it ; (. Sorry, you'll have to consult an online howto.

I think you're right about the pxegrub thing; looks like emerge doesn't encorporate these configuration flags yet. I mean to get it working some time, but since none of my diskless machines have bootable NICs, it seems pointless to bother now. At the moment, I have them booting from floppy instead. ; )
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erik258 · Posted: Wed Jan 03, 2007 6:55 pm Post subject:

I got a box of nice PXE-enabled 3C905s and am back on the project now. I also got a whole new message after booting grub! This time i dowloaded grub-0.97 and patched (won't compile w/o), then, copied grub over and booted as previously.

Here's the last lines.

erik258 · Posted: Wed Jan 03, 2007 7:19 pm Post subject:

evidently PXE booting with grub is now broken. I recommend PXELinux as a replacement. Looks like i should have listened to everyone else, my kernel is booting fine now.

here's the howto i found useful:
http://www.gentoo.org/doc/en/diskless-howto.xml
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jesse_kahtava · Posted: Tue Jan 23, 2007 6:27 pm Post subject:

Hello.
I've followed this howto as well as http://www.gentoo.org/doc/en/diskless-howto.xml and everything but nfs as root seems to be working. Here's the bottom bit of output:

erik258 · Posted: Wed Jan 24, 2007 10:44 pm Post subject:

I've encountered that error once. It means either that init itself (/sbin/init) can't be found, or can't be executed, or else (this was my problem) the libraries it needs can't be found.

jesse_kahtava · Posted: Wed Jan 24, 2007 11:04 pm Post subject:

I've already completely disabled NFSv4 support in the kernel so I expect it's using NFSv3.
Also, I checked that init is in the right place and it executes within a chroot.
The error value of 45 is mainly what's concerning me since it spits out a bunch of them before finally giving a kernel panic.
I don't think it's able to read from the NFS mount at all.
Oh, and nfs-utils is installed. As I said though, i'm under the impression that it's completely unable to read from NFS.

erik258 · Posted: Thu Jan 25, 2007 10:25 am Post subject: