[Server-devel] Edublog Beta Server shipped!

Samuel Klein sj at laptop.org
Wed Jul 2 15:52:20 EDT 2008


Tony, this is fantastic; thanks for all of the work you put into this.
--SJ

2008/7/2 Tony Pearson <tpearson at us.ibm.com>:

>
> 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
> Server-devel at lists.laptop.org
> http://lists.laptop.org/listinfo/server-devel
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.laptop.org/pipermail/server-devel/attachments/20080702/c9a4a40d/attachment-0001.htm 


More information about the Server-devel mailing list