Tony, this is fantastic; thanks for all of the work you put into this. --SJ
2008/7/2 Tony Pearson <[EMAIL PROTECTED]>: > > Team, > The XS School Server we build for Edublog has been shipped to its final > destination today! This is in support of Proyecto Ceibal of OLPC Uruguay. > Details of the poject here: > http://wiki.laptop.org/go/Educational_Blogger_Project > > Some key lessons learned: > > (a) XS install on machine with two disk drives > > The unattended-kickstart XS-163.iso image only works when there is a single > disk drive. If you have two or more disk drives, disconnect them during the > initial install. Other than that, the parts list for the hardware, and > pictures of the assembly are here: > http://wiki.laptop.org/go/User:Az990tony/edublog-beta-hw > > (b) I was able to get "multi-boot" working. > > I still need to update my notes on this page: > http://wiki.laptop.org/go/User:Az990tony/edublog-beta-sw > > The OS images are: > > 1. XS-163 ( what we plan to do our primary development/test) > 2. Fedora 7 (for comparison/test purposes) > 3. Debian 4 (for potential porting of Edublog) > 4. SysRescCD (to repair the other three) > > The method could be extended to dual-boot for XS with WIndows for example, > and maybe even XS with Apple Mac OS X. Let me know if there is any interest > in either Windows or Mac OS dual-boot scenarios. > > (c) RAID and LVM2 > > While the BIOS of the motherboard advertised "RAID" capability, this is > only BIOS-assisted RAID for Windows device drivers. Linux calls this "fake > raid" and is only supported on a few motherboards, but the one we had was > not on the support list. I was able to get instead "software raid" > mirroring "raid1" and LVM2 logical volumes, but had troubles with this > process. Converting regular partitions to raid, or regular partitions to > LVM is straight-forward, but converting either of these to LVM2+RAID was > fraught with problems, especially if the LVM2+RAID contain any "root" > directories needed to start the OS image. For now, LVM2+RAID should only be > used only for shared data directories that are non-essential for OS boot. > > (d) Remote administration with SSH > > Our development team is all over the place, so we set up "sshd" server with > DSA private/public key pairs. To make this feasible, I put the "/home" > directory on LVM2 logical volume so that all of the OS images could access. > Fedora and Debian have different default userid value starting points, so I > used "groupadd -g nnnn " to create a group, and "useradd -g nnnn -u mmmm > user" to create the users on each OS image. This ensures that everyone can > read their own files regardless of which OS image they are running with. > > I tested with a Windows SSH client (sshWindows on SourceForge.net), and was > able to access the server successfully. > > (e) MySQL vs. PostgreSQL > > Despite Tim's excellent set of notes, I was unable to get past his > "test.php" phase, I just could not get Apache to have authorization to the > postgresql databases from the PHP pages. I hope the remote admin team can > figure this out when needed. As a fall-back, I installed MySQL which we > know should have no problems with Moodle. > > (f) Ethernet ports/devices/MAC addresses > > A very frustrating aspect of the multi-boot process is that each OS assigns > different "eth0/eth1/eth2/eth3" for the devices it finds. Following the > XS-163 scheme of "eth0" being the WAN connection to the outside world, and > "eth1/eth2" to be the internal LAN connections, there were means to set > Fedora and Debian to match. This way, "eth0" is always the WAN connection > regardless of OS image currently running. > > (g) Backup methodology > > Seeing that moving partitions around, converting to raid, and LVM2, > required a backup method, but the "Mondo Rescue" method deployed in > OLE/Nepal did not handle the raid/LVM2 very well. > > Instead, I was able to use "SysRescCD" (from http://sysresccd.org/) which > is developed in France, and has English and Spanish instruction manuals. > This was able to understand raid and LVM2 devices, and has "partimage" tool > to backup regular partitions, raid-mirrored partitions, and LVM2 logical > volumes. > > (h) Boot-CD and Recover-DVD > > Part of the project was a "nice-to-have" requirement for a Recover DVD to > rebuild the machine to original working state in case the devlopers do > something bad that breaks the system. I chose SysRescCD, customized to run > "sshd" on boot with the appropriate settings, users and public keys in > place. I created a "Boot-CD" that is only 200MB, and a Recover-DVD which > boots just like the Boot-CD, but has 3.7GB of backup files (mostly from > "partimage" tool). I did not have time to fully test an automated recovery, > but was able to summarize the seven steps involved. The advantage is that > these seven recovery steps can be done by remote administration, you only > need someone to reboot the XS with the Recovery DVD, and let the remote > admins do the rest. > > (i) Rescue OS image on the disk drive itself > > I wanted to put the SysRescCD on the hard disk itself, but again it assigns > "eth0/eth1/eth2" differently than what I had already done with Fedora and > Debian. I worked with my new friends at SysRescCD, and they added a kernel > parameter "nameif=" that allows me to specify "eth0" to be the motherboard > port, "eth1" to be the top NIC and "eth2" to be the bottom NIC card, just as > they are defined with the other OS images. Here is the description: > > > http://www.sysresccd.org/news/2008/06/28/option-to-define-the-name-of-a-network-interface-using-the-mac-address/ > > With this parameter, I was able to match the "eth" settings of XS-163, and > have it as a fourth "boot OS" image. While SysRescCD can be put onto > existing OS image partitions, I chose instead to put this as /dev/sda1, and > moved the shared /boot directory to /dev/sda2. > > Hopefully, it will arrive and be online for development purposes next week. > > Tony Pearson > http://wiki.laptop.org/go/User:Az990tony > _______________________________________________ > Server-devel mailing list > [email protected] > http://lists.laptop.org/listinfo/server-devel > >
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