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Three weeks ago, the technology world was aflutter with buzz of the iPad. But with yesterday’s MeeGo announcement from Intel, the Linux Foundation and Nokia, it appears that Apple could have a Linux-based competitor for tablets, netbooks and other categories of devices. …… read more
This is at it’s heart an update to RHEL 5. But Redhat is promoting it as “the first product to deliver commercial quality open source virtualization featuring Kernel-based Virtual Machine (KVM) hypervisor technology.” The kernel version is still 2.6.18, with backported patches. Redhat is promoting upcoming Red Hat Enterprise Virtualization products along with RHEL 5.4 on the announcement page . The server release is touted as providing “the most cost-effective, flexible, and scalable environment”. There are two flavors, Red Hat Enterprise Linux and Red Hat Enterprise Linux Advanced Platform. The number of guests on Advanced Platform is unlimited while the standard release is limited to four guests. Redhat Enterprise Linux is certified as a guest OS on the following platforms:
Redhat Enterprise Linux supports three distributed system technologies:
Redhat also has new managment tools for managing virtualized environments. And of course it provides tools like Samba for integration into Windows environments, Apache Web server, MySQL and Postgresql databases. And of course all the enterprise network services such as DNS, dhcp, and firewall capabilities are included. Redhat is also promoting Redhat Enterprise Desktop as an alternative to “proprietary” desktop operating systems. They’re selling the “security” features and cost benefits of managing their system. And if you must run one of those “proprietary” systems, they offer virtualization to run it as a guest OS. While not everything on RHEL 5.4 is the latest release, it does provide the kind of system and support that will make management comfortable. Subscribers to RHEL 5 will get the updates automatically for free. New subscribers will pay about $349 for the server version and prices start at $80 for the desktop version. I got a call from a customer asking for help with a subversion server that suddenly went off-line. The system was running SuSe 10.1, apache2 and subversion, and almost nothing else. It had been operating for 2 years in the server room, in a headless configuration. The developers that used it connected with their Windows machines and everything worked flawlessly for two years. Suddenly, last week, it became unresponsive. They tried rebooting the server, nothing worked. nothing had changed in the configuration, and since this machine was only accessible in the LAN, and protected by a firewall, they hadn’t even done any upgrades. Their attitude could best be described “if it’s not broken, don’t fix it”. Before I was called in, the customer had installed a new ethernet card, on the assumption that the on-board card had failed. They came to that conclusion because they couldn’t ping out, and no other machines could ping the server. A good assumption, I think. However, the new ethernet card didn’t fix the problem. That’s when they called me in. We went through the configuration with a fine tooth comb. We disabled Network Manager, since I’ve known it to cause issues on some systems. Everything seemed fine, but the network still didn’t work. The network configuration was static. So we changed to using dhcp to get an address. This worked, it got an address, but we still couldn’t ping either direction, from the server or to the server. We looked for alternate kernels we could boot, to see if it was a kernel specific problem, however there was only one kernel available. As I recall there wasn’t even a failsafe option in the boot menu. As part of the diagnostic process we put a laptop on the wired network and tried pinging it from the server. No response. we checked the ARP tables and there was an entry for the server we was working on, with it’s IP and MAC addresses. We concluded that the server could “talk” but couldn’t “hear”. We checked for firewall rules that might be blocking. There were none. We checked the arp tables on the server, and there were entries, without host names, for other machines on the network. None of us had see this before. The plot thickens. So next we decided to try a Knoppix live CD to test the hardware. we figured if Knoppix worked, then there was a software configuration problem. Sure enough, Knoppix booted and networking was working. We could ping, other machines on the network could ping the server. So we concluded that it must be something in the software. We again, went through the network configuration files. Suspecting that there may have been some corruption in the files, we manually rewrote them from scratch. We thought there was a possibility of unprintable characters in the configuration files that was causing them not to work properly. We flushed the firewall rules for good measure with iptables -F just to make sure there were no rules, that were not being reported by iptables -L. Still no change. Still operating under the assumption that there was a configuration errors somewhere, we decided to try an upgrade, to OpenSuSE 11.1. We backed up all the configuration files and data to an external USB drive. Then we did an upgrade. Upgrading is a pretty slow process, relative to a fresh install. Nothing changed. Next we tried a fresh install, no change. Then I tried another distributions, CentOS 5. Still no change. Finally as my frustration mounted, I did ifup eth0 and a root console popped up displaying an error message. “…. irq #66 disabled” So we googled the error and found that this kind of error appears when there are spurious interrupts on the bus. After a couple more tests we concluded that there was some kind of hardware problem, that we hadn’t seen before. Since the system was under warranty, we contacted the manufacturer and they replaced the motherboard. After a fresh install, the system came up and ran perfectly. This is one of the things I both love and hate about this business. Everyday there is a new problem to be solved that we’ve never seen before. I hope this saves someone else some time diagnosing their hardware problems. I’ve been working on a customers system, upgrading the motherboard and memory for better performance and reliability. We replaced an MSI motherboard with a SuperMicro Server board. When I tried to boot up the system after installing the new hardware, I got the following message in the screen.
It’s been a while since I had issues like this. So I went looking through Google for answers. Isn’t that what everyone does these days? Everything search showed seemed to indicate a problem with the the raid. So I tried to look for a problem with the raid partitions. First I used Knoppix. I found a web site Recover Data From RAID1 LVM Partitions With Knoppix Linux LiveCD I followed the instructions, using mdadm –examine –scan to examine the partitions and manually set up the raid. Everything worked fine. I could see the raid partitions, I could mount them and view the data. cat /proc/mdstat showed the proper raided partitions. So what’s the problem? Next I tried the rescue option of the Centos CD. The system booted fine, and the rescue mode dutifully mount all the partitions in the right order to /mnt/sysimage. But still no love when I tried to boot. Next I got on irc and talked to some of my friends from KPLUG. One suggested trying to boot to the grub prompt and running boot options by hand, using tab completion. He suggested that perhaps the system wasn’t recognizing the drive. It seemed plausible, so I tested it. But the system seemed to be finding the /boot partition just fine and tab completion found the init ram disk fine. Another suggested that the failure of the system to recognize the drives was caused by not loading the proper controller module. This had not occurred to me, because I thought I remembered that all the modules for hard drive host controllers were built into the kernel. At least that’s the way I used to build them. I remembered wrong. My friend suggested that I look at /etc/modprobe.conf and check the scsci_hostadapter parameter. So I booted into the Centos CD rescue mode, as the system booted I noticed the message loading ata_piix. This was the clue I had been missing. I edited the /etc/modprobe.conf file and changed the reference there. When I attempted to reboot the system the raid partitions were recognized and the system finished booting. Once upon a time, modules for hard drives were included in the kernel, not loaded at boot time. Now with the size of kernels getting very large, nearly everything is loaded at boot. That’s fine for things like ethernet and sound cards. It’s always been a point of pride with me, that we could take the hard drives from one system, and install them into another system and it would just run. I guess that’s no longer true. IMNSHO this is not progress. After some poking around I found the solution to my ldap problem. I started reading the log files, turned on debugging in the init.d file and determined ldap was not starting. I started reviewing and checking the So I started looking for it on my system. Not to be found. Not where it belonged in I installed the samba-doc package and the schema file in Once I found the Onward ………………. I recently decided it was time to upgrade my workstation from Etch to Lenny. Several of the applications were showing bugs and it looked like Lenny had stabilized enough to use it. I’m alway reluctant to upgrade. In my experience something always breaks, and I spend an inordinate amount of time figuring out how to repair the broken system. So I found the instruction Chapter 4: Upgrading from previous releases. I followed the instructions, except for recording the session. Next time I’ll probably consider doing this too. Everything seemed to go well. I managed to do the entire upgrade, while logged into the machine, and reading the web page in the browser running on that same machine. I was pretty impressed, I have to say. I was even able to chat on IRC with my friends while I did the upgrade. Nothing ever works perfectly. For some reason, every time I upgrade even the kernel, it messes up my /boot/grub/menu.lst My boot drive is /dev/sda2 but it keeps getting set to /dev/sdb2, go figure. After repeatedly having this problem, it really doesn’t bother me that much anymore. It’s just a minor annoyance. I have a samba share where I store all my Windows data files. I don’t trust Windows to keep my data safe, so I store it on my Linux machine. I use ldap for authentication. So after my upgrade I tripped over <a href=”http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=495954″ bug #495954</a> I found it interesting that this bug seemed to have been reported and verified by several people, but no one seemed to want to report a work around. Either my Google foo is weak, or no one has reported how to work around this. I’m in the process of reconstructing my authentication system from scratch. I also notice there is no samba3 schema file. I’m still trying to track this down. More later ……………………………….. I’ve been using Amarok for months to manage and listen to my digital music collection. I really like the interface. And I like the ability to manage my collection, add and manage tags and import music into my collection. Yesterday however, it lost my collection. My music is still all there. I was importing some music into my collection and the entire collection disappeared from the left panel. I could still view the files and I could still play, but the collection panel was empty. I ran Rescan Collection, it progressed to about 82% and then quit. I searched all over and this appears to be a common problem. And it doesn’t seem to matter if you’re using MySql as I am or sqlite. I tried all the suggestions posted to the amarok forums, nothing worked. I basically wiped out all my amarok configuration files and started over, with the same result. So I checked around and found there is an IRC channel #amarok. I thought I would give that a try. Although there were a lot of people in the channel, no one responded to my questions. Finally a smart-ass posted and said that I should try something else since Amarok was bad software. Although I wasn’t quite ready to accept this at face value, I was somewhat surprised that someone would make a statement like this on a support channel. I continued to search for a solution, to no avail. It seems there is a bug in Amarok that causes it to fail to manage the collection list once it gets to a certain size, or if it encounters a file with some kind of error. I even ran amarokcollectionscanner manually to see if I could spot an error. Nothing appeared, though it seems to not complete scanning the entire collection. I checked and it appears that my MySQL database is intact. It looks like, for whatever reason, Amarok can’t or won’t access it. Finally out of frustration, I started looking at other applications. So far Rhythmbox seems to be working well. It does most all the things that Amarok does. It doesn’t seem to have the tagging capabilities that Amarok has, but it sees and displays my entire collection, so that’s a start. I’ll continue to look at other applications to replace Amarok. I’ll write about it when I have time. Update: I went from Etch to Lenny and tried Amarok again. This time it scanned my collection and rebuilt everything just fine. Probably a bug in the old version that’s been fixed. I’m happy. Just completed my review of the EnGarde 3.0.22 Community Firewall. I would use and recommend this product. I think this is one of the better open source firewalls I’ve looked at. With the default install, less a few packages, it looks to be a very secure system. The WebTools seem to work well enough. It’s a small footprint, so it would be easy to repurpose a previous generation workstation to run as a firewall, if you’re on a tight budget. |
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