Somewhere out there!

These guys have an interesting looking project called Enomalism Virtualized Management Console which is an open source web based Xen domain management console. After looking at the screen shots, I’m looking forward to seeing how it functions. They have some futher work which seems to leverage this to provide an integrated collaborative content management for business called TYfresco. Combining Zimbra, Sugarcrm and, a new project for me, Alfresco.

I tried to get Zimbra running recently on an Amd64 Debian domU, but ran into 64bit issues. After several attempts at compiling Zimbra, I figure my next try will be with a 32bit chroot.

Anyway I’ve also been thinking along these lines and better Xen management recently. I’ve been considering building my own system based on Cfengine and Layed Subversion. Cfengine is meant to be very powerful, and is some thing I’d like to spend time learning regardless. Laysvn seems easier to use now, however I’m in two minds about its functionality. The balance been easy of use and security is something I have to explore further.

I see a tool like this as being useful for both deploying new and migrating old servers, plus the restoration management in the event of a system failure. However this needs to be balanced against the leakage of system security information from files like /etc/shadow. On one hand it’s important to store this, on the other with a bad implementation it increases the risk that secure information will leaked. Another thing to consider, as indicated by several comments on Tracking, auditing and managing your server configuration with Subversion in 10 minutes, is permissions management.
Finally I saw this cool looking admin tool on freshmeat in my rss reader Great News today. Network wide updates for systems which use APT, or nwu. Maybe this is something I figured I could do with cfengine, or maybe it’s something that can be combined with cfengine. However, very useful work.

As more systems are run on Xen, making it much easier for sysadmins to partition their services on the same hardware and therefore make system maintenance easier on the application. Better tools will have to be produce to assist management on the OS level.

Technorati Tags: xen, etc, management, cfengine, laysvn

Until today I hadn’t taken the time to upgrade to the latest Xen 3.0 testing. Here’s a quick note if you keep getting this error and can’t figure it out: ERROR: Xen will only load images built for Xen v3.0.

Make sure you have:

kernel /xen-3.0.gz dom0_mem=262144 com1=38400,8n1

instead of:

kernel /xen-3.0-devel.gz dom0_mem=262144 com1=38400,8n1

Technorati Tags: xen

Some useful hints for running Debian/domU from the Xen Wiki:

I encountered the following problems when setting up Debian 3.1 as a DomU on Xen3.0 Unstable for the XenDemoLaptop:

1. When booting, I get “Couldnt get a file decriptor referring to the console” about 100 times.
• Fix: Remove /etc/rcS.d/S05initrd-tools.sh
2. When booting, I get lots of “FATAL: Module blah not found”
• Fix: Remove offending modules from file /etc/modules
3. When booting, after it says “Starting hotplug subsystem:” some of the say “[failed]”
• Fix: Move offending modules out of /etc/hotplug/

Sun’s released ZFS for OpenSolarias and it looks very cool. Couple of flash demos show how easy it is to manage and its selfhealing abilities.

It would be very interesting to see the possibilities of this combined with OpenSolarias acting as a dom0.

I seem to be doing this a lot at the moment. So I’ve collected a few notes together as reminder of the process.

Had a difficult week testing Xen 3.0 on my new v20z dual Operton machine.

Seems I was missing hotplug, which Xen 3.0 needs installed into domO in order to initialise the creation of block devices correctly. I’ll have more to report once I’ve got NX going, plus a 64bit domU guest.

A useful comment about a networking issue with Xen. Something I’ll have to try out at some point.

On a separate but still networking issue, I noticed that my XenU’s outbound traffic is sporadic (between 800KB/sec and 2MB/sec). The problem is the default qdisc being inadequate. So I fix it with:

XenU# tc qdisc add dev eth0 root tbf rate 50mbit latency 20ms burst 50k

TBF requires kernel option CONFIG_NET_SCH_TBF, but other qdisc should work too if the buffer is large enough to handle the bandwidth. To make this permanent, add it as a ‘up’ line to iface eth0 in XenU’s /etc/network/interfaces.

I’ve just moved into a new center, combined with this change I’ve fixed a Xen configuration [1] bug that has been plaguing this site with timeout errors. The addition of SunFire V20z at the end of the month should also improve performance, and also allow me to take my Xen/NX desktop testing to the next level.

[1] vif configuration error where 00:01:00:101 and 00:01:00:01 resolve to the same 00:01:00:01 MAC. The former should be 00:01:01:01.

On Friday my NX desktop started playing up a little. So I rebooted. Kernel root VFS mount error! Very nice. After some testing, it was the first time I’d seen a faulty HDD bring down the Linux kernel even when booting from a Live CD rescue disk. Damn!

Luckily, I was using NFS home directories and avoided “where is that month old backup” mode.

One of my goals with NX and Xen is to achieve Thin Guy‘s level of desktop support. Zero!

Sun Ray = Office Supplies. You can’t “Fix” a Sun Ray. Out of the 33,000 Sun Ray desktops inside of Sun, how many “desktop” techs do you think are required to manage that install base? How does the number zero grab you? On the ultra rare occasion that something happens to your Sun Ray (let’s say a power supply failure), you replace it and send it back for a warranty replacement (5 years on the SR1g). In the meantime you walk to the closet, grab a spare and plug it in and pick up exactly where you left off. Anyone who can replace staples in a stapler or replenish their supply of post-it notes can replace a Sun Ray