Sunil, I don't recall seeing any documentation on those parts. I had to poke around looking at parts of xCAT to see how it worked. It's been a few years since I did that; so, I don't remember much about the process. My recommendation would be to start looking at things in the rootimg.gz image. Looking at it now, I see that /opt/xcat/xcatdsklspost gets run when rootimg.gz boots. It looks like it downloads all of the postscripts from the management node and then run getpostscript.awk which issues a command to xcatd to get the primary postscript for that machine. I've forgotten how xcatd then builds the primary postscript. I do remember that in the partimageng.pm module, I had it add the partimageng postscript.
So, you'll really have to start digging through how the xcat postscript system works. Josh On Tuesday June 07, 2011, Sunil Venkatesh wrote: > Josh, > > Is there any place I could find some details on > > "... /Once the compute node is booted with the stateless > image, it uses NFS to mount some things from the management node, and then > runs some xcat postscripts,/.... " > > I have the stateless images ready with partimage compiled for PPC. For > the compute node (power 7) to boot using the stateless images, i need to > configure the yaboot instead of pxeboot (which is specific to x86). I > wanted to know where in the startup files the execution of partimage and > NFS mount is configured. Is it configured by the "genimage" command > itself? Considering the way in which the nodes are configured in the > network, it would not be a good idea to let xcat take care of > configuring the details like DHCPD for netboot. So, I need to make > changes to the configuration files manually, which is why this query > came up. > > Thanks in advance. > > Regards, > Sunil > > On 6/1/11 1:39 PM, Josh Thompson wrote: > > Sunil, > > > > The "stateless" image I refer to is what is actually booted on the > > compute node containing the image to be captured. It's called stateless > > because it is loaded completely in RAM and does not maintain any state > > when a reboot occurs. > > > > The partimage binary is part of this stateless image and actually runs on > > the compute node. It does not run on the management node. The > > management node does not have block level access to the disk on the > > compute node to be able to capture the image from the disk. > > > > I'll try to describe the process a little better. The management node > > issues a reboot command to the compute node. The compute node uses PXE > > to load and boot a kernel (vmlinuz), initial RAM disk (initrd.img), and > > a root filesystem (rootimg.gz) from the management node. All three of > > these together make up the stateless image. Once the compute node is > > booted with the stateless image, it uses NFS to mount some things from > > the management node, and then runs some xcat postscripts, one of which > > is the partimageng postscript. This postscript determines what > > partitions are on the compute node and, depending on how the postscript > > is configured, uses partimage or partimageng to capture an image of the > > compute node disk that is then saved to the management node. When it is > > finished capturing the image, it notifies xcat on the management node > > and then reboots. xcat reconfigures itself to tell the compute node to > > boot off of disk at next boot. When the compute node comes up, it uses > > PXE to ask the management node how to boot. The management node tells > > it to boot off of disk. > > > > I hope that clarifies how the system works. If any of it is unclear, > > please ask for further clarification. > > > > Josh > > > > On Wednesday June 01, 2011, Sunil Venkatesh wrote: > >> Josh, > >> > >> I had one more clarification. > >> > >> partimage binaries run in the management node to capture an (stateless) > >> image from the compute node right? In that case, is there a need for > >> these binaries to go into the rootimg.gz?? > >> > >> My assumption is, partimage runs on the management node (an intel blade > >> in our case) to capture a stateless image from a compute node (a power 7 > >> blade) and stores these images under " /install " of the management > >> node. Please correct me if I am wrong here. > >> > >> Regards, > >> Sunil > >> > >> On 6/1/11 9:58 AM, Josh Thompson wrote: > >>> -----BEGIN PGP SIGNED MESSAGE----- > >>> Hash: SHA1 > >>> > >>> On Tuesday May 31, 2011, Sunil Venkatesh wrote: > >>>> Hi, > >>>> > >>>> I used the steps that were mentioned under > >>>> > >>>> https://cwiki.apache.org/confluence/display/VCL/Adding+support+for+par > >>>> ti mag e+and+partimage- ng+to+xCAT+2.x+%28unofficial%29 > >>>> > >>>> to enable partimage support for xcat. I wasn't sure if I need to > >>>> change references to x86& x86_64 (as directories) to reflect the > >>>> ppc architecture, as the web page says "The architecture for the node > >>>> must always be set to x86 for this..". I have with me the vmlinuz > >>>> (kernel image) and initrd for the capture process. The 2 nodeset > >>>> commands > >>> > >>> By this, do you mean you have vmlinuz and initrd for your power blades, > >>> not the ones linked to off of the page you listed above? If you do, > >>> that's a good start. However, you'll also need rootimg.gz. rootimg.gz > >>> is the root filesystem for the stateless image. It also contains the > >>> partimage and partimageng binaries. Assuming partimage or partimageng > >>> can actually capture partitions from power systems, you'll need to > >>> compile at least one of them to run on power. For the rootimg.gz image > >>> I provided, I compiled them statically so that I didn't have to worry > >>> about including any library dependencies in rootimg.gz. > >>> > >>> It would be a good idea to research how to use xcat's genimage command > >>> to generate stateless images to learn how to do this. > >>> > >>> If there's any part of the above that you don't fully understand, > >>> please ask me to clarify it. Until you have a stateless image that > >>> you can deploy to your power blades, there's no point in trying to > >>> debug any VCL specific items. > >>> > >>> Josh > >>> - -- > >>> - ------------------------------- > >>> Josh Thompson > >>> VCL Developer > >>> North Carolina State University > >>> > >>> my GPG/PGP key can be found at pgp.mit.edu > >>> -----BEGIN PGP SIGNATURE----- > >>> Version: GnuPG v2.0.17 (GNU/Linux) > >>> > >>> iEYEARECAAYFAk3mRYsACgkQV/LQcNdtPQNnVgCbB9ZFJn0+C45RC/g75RqGZY/j > >>> PZYAniP2Eam7nxgiDWUnp5sKPYPO4OMa > >>> =exBV > >>> -----END PGP SIGNATURE----- -- ------------------------------- Josh Thompson Systems Programmer Advanced Computing | VCL Developer North Carolina State University josh_thomp...@ncsu.edu 919-515-5323 my GPG/PGP key can be found at pgp.mit.edu All electronic mail messages in connection with State business which are sent to or received by this account are subject to the NC Public Records Law and may be disclosed to third parties.
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