I am trying to install Xen on Centos6.5 based on this tutorial (http://wiki.centos.org/HowTos/Xen/Xen4QuickStart), however after installing xen and running the script to edit the grub.conf, i am not able to boot into the new kernel.
I get an error stating -
invalid magic number: 9090
Error 13: Invalid or unsupported executable format
Can someone help me please?
Current suspicion: http://wiki.centos.org/HowTos/Xen/Xen4QuickStart definitely not a 10 minute install for all platforms???
History: there is a Centos Bug on this: centos.org/print_bug_page.php?bug_id=6503
I repeated a similar process:
(1) Install Centos 6.6 (Centos kernel: 2.6.32-504.el6.x86_84) from DVD1, DVD2 with Install using only the CENTOS Repo
(2) Installed Xen (Xen4CentOS kernel:3.10.56-11.el6.centos.alt.X86_64) Issuing the following commands from the centos command line (as root, warnings from readers accepted as correct from a security standpoint) To abate the security concern, no network connection existed as an offline repo would have been used but was not actually needed for the Centos minimal install.
yum install centos-release-xen
yum install xen
/usr/bin/grub-bootxen.sh
from the Xen/Centos reference: http://wiki.centos.org/HowTos/Xen/Xen4QuickStart
I noticed that the /boot/grub/grub.conf file was non-existent and tried to reboot without it. The reference above suggests it should be there, so I am proposing that your grub.conf file was missing or incorrect because my results were similar:
'invalid magic number: 9090
Error 13: Invalid or unsupported executable format
Press any key to continue...'
So as of now I can reproduce the problem. I will be updating this as I discover what will solve it for my solution, post it with hope it fixes it for yours or others who share similar issues.
I noticed something odd, I was using a Combo USB hub and tried to reboot using the other kernel (2.6) and there were considerable failures which were squawking on the startup screen and it would not permit me to start. When I removed it I could not boot into the 3.10, but only into 2.6.
Ok, a quick find on grub.conf revealed a similar version to that shown on the reference link above in /etc. So I copied the grub.conf from /etc to /boot/grub and rebooted. But I too see similar results. The USB hub is off the system and will not be reattached, so there is something else here that needs review. I'm digging into the grub.conf file at this time...
(update) I see that there is a grub.conf file under /boot/efi/EFI/redhat. Oddly in the Centos 'bug archives' there appears to be a related resolved bug for Centos 7: bugs.centos.org/view.php?id=7242 (cannot post this as a link as my reputation is less than 10, my apologies)
Also, as this relates to magic number here are results for my type of files and magic numbers, but I have done this with vi and have some assumptions here about what I saw, so I am retrying this with the help of the other stackoverflow article which uses file-devel package LibMagic... here are the intermittent results.
File.x86_64 Magic number (if two bytes, just use first 2)
vmlinuz-2.6.32.504.el6.x86_64 /0x8c/0x8e/0x8e/0x8e
vmlinuz-3.10.56-11.el6.centos.alt.x86_64 /0x8c/0x8e/0x8e/0x8e
Note: A search of '9090' on centos.org using the provided search engine for words on the site yielded no response on 12/22/14: #wiki.centos.org/Search
There is no mention of installation problems with SELinux, even though I have set:
SELINUX=disabled
in the /etc/sysconfig/selinux file and
yum uninstall xen
yum install xen
/usr/bin/grub-bootxen.sh
No results, and no new grub file in any of the three locations listed above. /etc /boot or /boot/efi/EFI/redhat.
Comparison of the grub.conf files with other sources, show that it is reasonable. Same for the grub-bootxen.sh file based on what I could decipher from bash.
Changing the timeout in grub.conf (all I found) to 15 and removing the hiddenmenu command by #hiddenmenu, did not eliminate the '9090' error. Using: wiki.xen.org/wiki/RHEL6_Xen4_Tutorial which shows the 'kernel' modifier instead of the 'module' and changing the 'module' in front of the .img file to initrd, did not change the results.
OK. Reload.
1) reinstall minmum Centos
2) disable SE Linux
3) reboot
4) correct ifcfg-eth0 (remove NM and allow boot on startup) and service network restart
5) yum import centos-release-xen (accept import of GPG key)
6) yum install xen
7) investigate what occurs with "grub-install hd0" which produces '9090' error!
Ok, I would have to say that the question was not well defined. It is now well defined and can be posed as a question. I will convert this info and my trials to a reasonable question to see if anyone can assist with pointers...
Related
Currently I'm experimenting with the Cell/BE CPU under Linux. What I'm trying to do is running simulations in the near future, e.g. about the weather or black holes.
Problem is, Linux only discovers the main CPU of the Cell (the PPE), all other SPUs (7 should be available to Linux) are "sleeping". They just don't work out of the box.
What works is the PPE and it's recognized as a two-threaded CPU with one core by the OS. Also, the SPEs are shown at every boot (with small penguins showing a red "PPE" in them), but afterwards are shown nowhere.
Is it possible to "free" these specialised cores for use by the Linux OS? If so, how?
As noone seems to be interested or can answer this question I'll provide the details myself.
In fact there exists a workaround:
First, create an entry point for the SPUFS:
# sudo mkdir /spu
Create a mount point for the filesystem so you won’t have to manually mount after a reboot. Add this line to /etc/fstab
spufs /spu spufs defaults 0 0
Now reboot and test to make sure the SPUFS is mounted (in a terminal):
spu-top
You should see the 7 SPEs running with 0% load average.
Now Google for the following package to get the runtime library and headers you need for SPE development:
libspe2-2.3.0.135.tar.gz
You should find it on the first hit. Just unpack, build, and install it:
./configure
make
sudo make install
You can ignore the build warnings (or fix them if you have obsessive compulsive disorder).
You can use pkg-config to find the location of the runtime and headers though they are in /usr/local if I recall.
You of course need the gcc-spe compiler and the rest of the PPU and SPU toolchains but those you can install with apt-get as they are in the repos.
Source: comment by Exillis via redribbongnulinux.000webhostapp.com
I'm trying to install CentOS7 using a kickstart file with a VM. I am using a netinstall version of the ISO.
When I try to put the URL in the kickstart file, it will take a long time to check the installation source, and then fail.
I have checked the ISO, installing successfully without kickstart and using this address for the source:
url --url="http://sunsite.rediris.es/mirror/CentOS/7/os/x86_64/"
However, when using kickstart file, I install and then fail with below error message -
Error setting up base repository
Even if I manually type it in after it errors out.
Does anyone have any ideas? I have reduced my kickstart file to just that one line and it still shows the same behaviour. I don't have this problem with kickstart using the minimal or full install ISO's.
I'm just learning Linux so I didn't realize you could switch into another screen and monitor the install/run commands simultaneously.
After doing so I realised it wouldn't resolve names.
My DNS is dead/isn't responding. Used kickstart to manually assign another DNS server to the interface. This allowed the install to resolve the url. This would explain why the install worked with the netinstall iso on its own, as it was using default settings.
Hope this helps someone.
I am working on implementing a temp patch (non-persistent) on my system as described here (while waiting for the official distro kernel):
https://bugzilla.redhat.com/show_bug.cgi?id=1384344#c13
I have tested a dirty copy on write script for the intent of testing the resolution of this bug on my system but note that I am getting a semantic error and that this bug is still active on my system:
SuperUser Shell ~/> # stap -g -p 4 fix.stp
semantic error: while resolving probe point: identifier 'syscall' at fix.stp:5:7
source: probe syscall.ptrace { // includes compat ptrace as well
^
semantic error: no match
Pass 2: analysis failed. [man error::pass2]
SuperUser Shell ~/>
With color (if that's your thing):
Reading this article:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/SystemTap_Beginners_Guide/errors.html
I see a brief explanation:
semantic error: no match for probe point, while resolving probe point foo
The events / handler function foo could not be resolved
altogether, for a variety of reasons. This error occurs when the
script contains the event kernel.function("blah"), and blah does not
exist. In some cases, the error could also mean the script contains an
invalid kernel file name or source line number.
Questions:
This is essentially stating that the syscall kernel function is not recognized, correct?
Has anyone successfully implemented this temp fix on CentOS 7.x yet?
Thanks for any help
PS: Sorry if this seems somewhat script kiddy-ish (I don't fully understand this hot fix yet).
Yes, I have successfully implemented this temporary mitigation on CentOS 7.
As described in one of the comments on that bugzilla entry, you need to install the both systemtap and the debuginfo for the kernel in order for this mitigation to work.
The commands given are:
yum install systemtap yum-utils
debuginfo-install kernel-$(uname -r)
Based on what you posted, presumably you already have systemtap, but the error you're getting suggests you need the debuginfo packages. The second command above should install the right stuff; you could also get the RPMs by hand from http://debuginfo.centos.org/ (this is what I ended up doing)
By the way, this mitigation using systemtap is not a real fix, it just makes one of the proof of concept programs fail. It is worth doing, but no substitute for a real patched kernel.
I don't understand why Red Hat and CentOS haven't pushed out patched kernel packages yet, Ubuntu and others had their updates out days ago. What's the holdup?
I know the purpose of "biosdevname" feature in Linux, but I'm not sure how
exactly it works.
I tested it with Ubuntu 14.04 and Ubuntu 14.10 (both 64-bit server editions)
and it looks like they enable it by default - right after system startup my
network interface has a name such as p4p1 instead of eth0, no customization
is needed. As I understood it, in order for biosdevname to be enabled, BOTH
of these two conditions must be met:
a boot option biosdevname=1 must be passed to a kernel
biosdevname package must be installed
As I already mentioned, both Ubuntu 14.04 and 14.10 seem to offer biosdevname
as a default feature: they come with biosdevname package already installed, I
didn't need to modify grub.cfg either - GRUB_CMDLINE_LINUX_DEFAULT has no
parameters and my network interface still has a BIOS name (p*p*) instead of a
kernel name (eth*.)
Later I wanted to restore the old style device naming and that's where the
interesting part begins. I decided to experiment a bit while trying to disable
the biosdevname feature. Since it requires biosdevname package to work (or
so I read here and there), I assumed removing it would be enough to disable the
feature, so I typed:
sudo apt-get purge biosdevname
To my surprise, after reboot my network interface was still p4p1, so
biosdevname clearly still worked even though biosdevname package had been
wiped out.
As a next step, I applied appropriate changes to /etc/network/interfaces in
order to restore the old name of my network interface (removed entry for p4p1
and added entry for eth0). As a result, after another reboot, ifconfig
reported neither eth0 nor p4p1 which was another proof that OS still
understood BIOS names instead of kernel names.
It turned out that I also had to explicitly change GRUB entry to
GRUB_CMDLINE_LINUX_DEFAULT=biosdevname=0 and update GRUB to get the expected
result (biosdevname disabled and old name of network interface restored).
My question is: how could biosdevname work without biosdevname package? Is
it not required after all? If so, what exactly provides the biosdevname
functionality and how does it work?
The reason biosdevname keeps annoying you even after you uninstall the package, is that it installed itself in the initrd 'initial ramdisk' file as well.
When uninstalling, the /usr/share/initramfs-tools/hooks/biosdevname is removed, but there is no postrm script in the package so update-initramfs is not executed and biosdevname is still present in the /boot/initrd... file used in the first stage of system startup.
You can fully get rid of it like this:
$ sudo update-initramfs -u
I play to self-study 6.001 with the video lectures and lecture handouts. However, I have some problems setting up MIT Scheme in Ubuntu (intrepid).
I used package management and installed MIT-Scheme, but it's obviously the wrong version to use. It should be 7.5.1 instead of 7.7.90
I followed the instructions from this website (http://ocw.mit.edu/OcwWeb/Electrical-Engineering-and-Computer-Science/6-001Spring-2005/Tools/detail/linuxinstall.htm)
So far, I've downloaded the tar file, and extracted to /usr/local. I have no idea what step 3 means.
Then I entered command
scheme -large -band 6001.com -edit
and the error is
Not enough memory for this configuration.
I tried to run under sudo mode, and this time the error is different
Unable to allocate process table.
Inconsistency detected
I have close to 1GB of free memory, with ample HDD space. What should I do to successfully set this up?
Step 3 means that you should type export MITSCHEME_6001_DIRECTORY=${your_problems_path}. If you don't want to type it every time you launch Scheme, you should put it as a string in your ~/.bash_profile file(in case you use bash)
About the problem itself, Google instantly suggests a solution:
sudo sysctl -w vm.mmap_min_addr=0(taken from http://ubuntuforums.org/showthread.php?p=4868292)
Instead of the package manager, you may also want to compile the portable C sources for Unix. I am using it happily.