Arrfab's blog Some tips and tricks, mostly around CentOS

I had today to deploy two CentOS 5.3 xen dom0 on two blades and then some domU's guests. Everything was fine except that when i used our traditionnal deploydomU script (which uses virt-install) it directly complained about memory issue. The exact message was " 'Out of memory', "xc_dom_boot_mem_init: can't allocate low memory for domain\n" " . Strange as I was sure that the dom0 had plenty of memory and the new guest was defined to use only 768Mb .. so what was the issue ? In fact, nothing related to memory : Our new machines get deployed through a pxe boot menu (with syslinux/pxelinux.0 and pxelinux.cfg) in the Labs zone, but a typo was inserted in that menu so that newer CentOS 5.3 x86_64 machines were in fact ... using i386 repo !  ;-)

It took me 5 minutes to consult the great oracle (aka google) , find the same issue and look at both new nodes to confirm with `uname -a` that I tried to deploy a x86_64 domU on a i386 dom0 ...

Hehehe, strange that the message is related to memory and not arch .. but several minutes later (and a coffee cup, machines being redeployed correctly *after* the pxelinux.cfg file was …

Recently I had to install a new server that will act as a mail server (Zarafa but that doesn't matter) and being member of a DRBD cluster (to replicate automagically the Zarafa MySQL DB and Attachments on disks to the other node) . Fine, except that only one physical node was at my disposal : we'll convert the existing M\$ Exchange server physical box to CentOS/DRBD after the migration. So what ?

I was thinking about that nice feature in mdadm when you want to create a Linux software Raid 1 array but with only one available disk ("mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 missing" for those of you who don't know that nice feature) and add the second disk later .. That would be cool to do exactly the same with DRBD : one node active and then add the missing one later .. Don't try to find a 'missing' parameter in the drbd.conf file .. but that's possible (even if not documented in the online docs). Do you remember that nice parameter you use when you initialize your first DRBD resource (drbadm -- --overwrite-data-of-peer primary \$resourcename) ? Why not testing it with only one available node ? Yes, it works .. In fact …

I recently received a new laptop (IBM/Lenovo thinkpad R61) and I installed it with CentOS 5.3 x86_64. I used (of course) the nvidia driver from RPMforge (for the nVidia Corporation Quadro NVS 140M card that the R61 contains) but i had issues when trying to suspend/resume : In fact it suspended correctly and resumed , but with a black screen (machine was reachable on the network) so it was a video driver issue. Here is the patch you need to apply to a hal file for the suspend/resume operation to work :

---

/usr/share/hal/fdi/information/10freedesktop/21-video-quirk-pm-el5-nvidia.fdi.orig  2009-07-08 17:04:21.000000000 +0200
+++ /usr/share/hal/fdi/information/10freedesktop/21-video-quirk-pm-el5-nvidia.fdi       2009-08-09 18:18:08.000000000 +0200
@@ -16,6 +16,10 @@
\<remove key="power_management.quirk.vga_mode_3">\</remove>
\<remove key="power_management.quirk.none">\</remove>
\<merge key="power_management.quirk.vbe_post" type="bool">true\</merge>
+
+          \<remove key="power_management.quirk.vbe_post">\</remove>
+          \<merge key="power_management.quirk.s3_mode" type="bool">true\</merge>
+
\</match>
\</match>
\</device>

As a lot of you have already seen the post (either on the CentOS mailing-list) or on http://planet.centos.org , something is happening within the CentOS project. Now that it's public, I can add my thoughts too on that "hot" topic. I started to use CentOS around release 3.4 (in fact converting a Whitebox linux to CentOS) and was really happy with the updates and also the contact with the team.What has changed since that time ? As you've probably read it already, Lance Davis, one of the CentOS Project founders and the "Leader" at that time, decided to not participate anymore in the project (absent from the lists/irc/events/etc ..) while still receiving money from the contributors. In fact, and that surely the point that hurted the most the whole CentOS crew, he never said what was the fund dedicated to the project and for what it was used/spent ! As most of the bandwidth/servers/mirrors are donations/contributions from ISP and other companies, I'll let your imagination work. Some months ago the whole centos.org domain (so website/lists/etc ..) were unavailable because the domain was not renewed (but locked) and the same issue …

Arrfab Public Keys (GPG & SSH)

GnuPG Key

pub  1024D/56BEC54E 2004-04-10 Fabian Arrotin
     Key fingerprint = 7A38 A620 E0B5 0E9F F919  407B 9D59 07A3 56BE C54E
sub  1024g/8C0D95C6 2004-04-10

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.2.2 (GNU/Linux)

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My key is also available on the server belgium.keyserver.net
You can import it directly with the following command :
gpg --recv-keys --keyserver belgium.keyserver.net 56BEC54E

SSH Key

You can find my SSH Public Key Here You can import my SSH Public Key with the following command :
cat id_dsa.pub >> \~/.ssh/authorized_keys

One other thing I learned from the Florian's talk last week-end is anyRemote . It can be used to control your Linux laptop (or the application started on your Linux laptop/desktop) , like for example OpenOffice Impress from your mobile phone (over IR/bluetooth/WiFi) . Of course that's not the only stuff that you can use for that : Dagrecently posted his WiiPresent package he wrote during the last Fosdem (co-authored with Didi) but in my case it's difficult to justify to my kids that 'Daddy has to steal one of your wiimote's because he wants to use it during an OSS presentation' . Advantage of anyRemote is that it's compatible with my Nokia mobile phone so I was interested in testing/using it. It was not available on RPMforge  .. until now ! : i've made a commit to the rpmforge svn yesterday (so expect the packages to appear in some days, when Dag's buildsystem will process them)

People in the meantime who don't want to wait can 'ping' me for the locally built RPMs for CentOS 5 ;-)

While I am/was attending a Zarafa summercamp for professional reasons, I discussed with Florian Haas (from Linbit/DRBD) about newer Heartbeat/Pacemaker packages landing or not in the CentOS Extras repositories (we didn't talk about DRBD itself which is already provided in the Extras repository while newer DRBD packages are actually in the [testing] one). That's true that I've myself not used/deployed heartbeat based cluster the last months (RHCS instead ...) so I didn't follow what happened on the Linux-HA/Pacemaker level. (I was just aware of the fact that Pacemaker was a replacement for the included Cluster Resource Manager within heartbeat 2.x). The actual heartbeat packages in the CentOS Extras repository were being packaged/built by Johnny but I'll probably have a look with Ralph about what we can do. Florian told me that he was using the RPMs built by the Novell/OpenSUSE buildservice. While I was following some interesting talks, I had a quick look to see if their SRPMS could be used 'as-is' and submitted to Mock. Unfortunately no. I (we ?) 'll have to do some cleanups/adjustements within the SPEC file to fit the Mock buildsystem. (OpenSUSE uses someting different of course)

But …

I had (for professional reasons) to look at the Compatibility List on the VMware website for the (recently released) vSphere 4 product. And the the surprise : they already list CentOS 5.4, even if not even in 'alpha' stage .. interesting

Is VMware a kind of 'time machine' ? :D

Today I had to migrate a customer CVS repository to Subversion. I looked after cvs2svn but I only found it (at least a 'working' version) in Rawhide. "No problem ! , I'll use my mock wrapper script on my build system" ... Except that instead of building a nice ready-to-go rpm, I ended with that error message :

warning: /builddir/build/originals/cvs2svn-2.2.0-2.fc11.src.rpm: Header V3 RSA/SHA256 signature: NOKEY, key ID d22e77f2
cvs2svn                     ##################################################
error: unpacking of archive failed on file /builddir/build/SOURCES/cvs2svn-2.2.0.tar.gz;4a2d65a4: cpio: MD5 sum mismatch
Error installing srpm: cvs2svn-2.2.0-2.fc11.src.rpm

Hmm, that famous problem Russ reported some time ago .  But instead of setting up a F11/Rawhide domU somewhere just to extract the sources/spec from the rawhide srpm , I just decided to modify my wrapper script around mock on my CentOS 5 builder. Instead of just downloading the SRPM and directly submit it to mock, I first install it with the --nomd5 rpm parameter (using rpm2cpio is also an alternative), and then recreate directly a SRPM with `rpmbuild -bs --nodeps` (with of course the correct --define ' ' values for my build system) and then submit the resulting …

While I used for several months the service offered by ScheduleWorld, I didn't like the idea that my calendar was stored elsewhere than on one of my machines. The fact that ScheduleWorld decided recently to switch to V2 (and now don't provide the service for free anymore), it pushed me to find a solution to sync my calendar between my Nokia E51 and my Linux laptop/computers. I really appreciate my Nokia mobile phone, but unfortunately it doesn't support iCal (and I've not found a symbian app that could do that ..) . The only protocols that the Nokia can 'talk' is SyncML or 'ActiveSync' (through their 'Mail for Exchange' free plugin) . That directly limits the scope for the backend. While I considered Funambol at a time (to use SyncML) , I finally ended with Zarafa (and Z-push) . It's all open-source (in the community edition though) and emulates an ical (and caldav support is now available in the 6.30 release) and Z-push emulates an 'ActiveSync-over-the-air' server so I'm now able to directly sync my calendar/contacts/tasks/mails from my Nokia mobile phone to the server (using a MySQL backend) and either use the Zarafa webaccess (that I don't use that much …