dependency problem xen from centos 5.3 to 5.7

http://www.centos.org/modules/newbb/viewtopic.php?topic_id=19677

i'm unable to update xen image (centos 5.3) using centos 5.7 repository.

the solution: yum --exclude=elfutils-libelf* --exclude=python* update

done this and finally i can do yum update. :)

http://www.linuxquestions.org/questions/linux-general-1/error-timeout-urlopen-error-timed-out-when-using-yum-on-centos5-2-a-722441/

finally i've found the problem
i think this error because of repository overload
so i edit /etc/yum.conf
and add line timeout=300 (default value is 30 sec)
now it's working...case closed


solution: #yum update yum

4gb seg fixup after reformatting

[root@linux ~]# rpm -q glibc.i386
glibc-2.5-65
[root@linux ~]# rpm -q glibc.i686
package glibc.i686 is not installed

it works as expected. now production server works but files gone. hope to get files back using backup disk.

[solved] 4gb fixup problem end

WARNING: try at your own risk.
2. not use this function when memory below 512MB
3. this break down my production server http://blog.apis17.info/2011/09/segmentation-fault-after-glibci386.html -reformat and reinstall solve the problem

finally 4gb fixup on xen is finally gone. (now i have openvz too :) 2.6.18-274.el5.028stab093.2xen

it fixed using i386 version of glibc

#yumdownloader glibc.i386

then yum downloading 'glibc-2.5-65.i386.rpm' package

#rpm -Uvh --force glibc-2.5-65.i386.rpm

it force 32bit glibc version. default my centos  use i686 even os 32-bit. you can read my previous entries. (thanks to cloudlinux forum)

after several hours recovering back from my lost glibc uninstall thanks to webmin saving my life.
and NEVER use this command rpm -e glibc


now i'm ready to get dangerous on production server. will update this post later.

updating dom-0 clock and problem [xen]

what de..

all dom-U mogok after update NTP time to actual time. after reading reading found this. damm..

https://www.centos.org/modules/newbb/viewtopic.php?topic_id=25237

the effect (dom-U only):

1. network cannot restart.

2. processor clock (at dom-U) not able to detect

3. not able to reboot

4. cannot start after shutdown

5. dom-U clock stop at 3.40AM (dam.. i must sleep dude)

finally swith off and on back. phew..

now clock is working and in correct time.

next reading and experiment will be (in case): http://dsumsky.blogspot.com/2009/01/running-ntpd-inside-xen-domu-or-not.html

lalala...

Proper way: after kernel update [xen]

Kernel Diary: this just to remind me proper steps to do after dom-0 kernel updates

1. log in into each dom-U and run

#yum update -y

this will update kernel devel and kernel headers on dom-U

failing to do this will make iptables not able to start

2. fix xen kernel script

this will update latest kernel on dom-U (do this on every dom-U before rebooting them!!)

# /script/fixxenkernel

http://blog.apis17.info/2011/01/fix-xen-kernel.html

3. xm list

this will list all dom-U

4. xm reboot

this will reboot dom-U server. or just reboot entire system.

if you have iptables problem after dom-U reboot please install kernel-headers

#yum -y install kernel-devel kernel-headers

iptables: Table does not exist (do you need to insmod?)

then,

#modprobe ip_tables

hope this will save some time to figure up why iptables not working.

remember: i'm using hypervm. fixxenkernel scripts only available on hypervm

iptables after kernel updates [ solved ]

i have this

can't initialize iptables table `filter': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded.

to fix this problem

#yum update

Dependencies Resolved

================================================================================

Package Arch Version Repository Size

================================================================================

Installing:

kernel-xen i686 2.6.18-238.19.1.el5 updates 18 M

kernel-xen-devel i686 2.6.18-238.19.1.el5 updates 5.5 M

Updating:

curl i386 7.15.5-9.el5_6.3 updates 233 k

kernel-headers i386 2.6.18-238.19.1.el5 updates 1.1 M

Transaction Summary

================================================================================

Install 2 Package(s)

Upgrade 2 Package(s)

done..

:)

[Xen] Save file location

cd /var/lib/xen/save

this is path used by xen to store virtual machine state before shutdown/reboot.

i use du -lsh /var/lib/xen/* to trace what folder make my disk space full

Before

Filesystem Size Used Avail Use% Mounted on

/dev/hda6 8.6G 8.6G 0.0G 100% /

After

Filesystem Size Used Avail Use% Mounted on

/dev/hda6 8.6G 7.1G 1.1G 88% /

Solved.

quit from xen console

list all xen machine

xm list

enter console mode

xm console

quit from console mode

press Ctrl + ]

done! :)

thanks to: http://lists.xensource.com/archives/html/xen-users/2008-01/msg00086.html

nat disabled after kernel update (xen)

Iptables problem

Trying to start iptables gives :

iptables v1.3.5: can't initialize iptables table `filter': iptables who? (do you need to insmod?)

Perhaps iptables or your kernel needs to be upgraded.

Trying to “modprobe iptables” also gives an error message :

FATAL: Could not load /lib/modules/2.6.18-53.1.6.el5xen/modules.dep: No such file or directory

Here what I did to fix the problem:

• yum install kernel-xen kernel-xen-devel
• /sbin/depmod

After that, /sbin/iptables -L now works correctly!

ref: http://blog.jphoude.qc.ca/2007/11/17/xen-troubleshooting-centos-5/

found reference for openvz: http://thelinuxnoob.com/linux/enable-nat-module-for-vps-can%E2%80%99t-initialize-iptables-table-nat%E2%80%99-table-does-not-exist/

rebuild xen dom-u kernel

symtom: after dom-0 reboot, all dom-u not in latest kernel. to fix this,

cd /usr/local/lxlabs/hypervm/httpdocs/

lphp.exe ../bin/misc/fixcentos5xen.php

http://markus.revti.com/2010/08/hypervm-xen-installation/

not able to login xen console

xenconsole: Could not read tty from store: No such file or directory

as root:

/usr/sbin/xenconsoled

problem solved.

ref: http://wiki.xen.prgmr.com/xenophilia/2008/03/chris-xenconsole-could-not-rea.html

updating from 5.0 lenny to 6.0 squeeze

http://www.howtoforge.com/how-to-upgrade-debian-lenny-debian-5.0-to-squeeze-debian-6.0-on-xen-vps

posted for future reference.

4gb seg fixup on debian

linux02:~# apt-get install libc6-xen

trying this on debian.

Updates:

after install libc6-xen successfully, you need to fire:

echo 'hwcap 0 nosegneg' > /etc/ld.so.conf.d/libc6-xen.conf && ldconfig

Then reboot.. message gone! :)

another debian problems solved.

iptables problem with debian on xen

module-init-tools

the error

stats:/etc/snmp# iptables -L -v
Note: /etc/modules.conf is more recent than /lib/modules/2.6.18-8.1.15.el5xen/modules.dep
modprobe: QM_MODULES: Function not implemented

modprobe: QM_MODULES: Function not implemented

modprobe: Can't locate module ip_tables
iptables v1.3.6: can't initialize iptables table `filter': iptables who? (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

sh-2.05b# depmod depmod: QM_MODULES: Function not implemented 

Solution

apt-get install module-init-tools

done!

ref: http://forum.lxcenter.org/index.php?t=msg&goto=56813&

freebsd again

after comparing the bsd variation, i found that openbsd is more suitable for servers

http://forums.whirlpool.net.au/archive/488714

this brought me to http://www.openbsd.org/

and Open BSD as Xen dom U

http://wiki.stocksy.co.uk/wiki/OpenBSD_as_a_Xen_domU

this is interesting.

install freebsd on xen domU domain

i'm reading this

http://forums.freebsd.org/showthread.php?t=10268

and this

http://www.netbsd.org/ports/xen/howto.html#netbsd-domU

will be long day then. :)

4gb seg fixup, process tailwatchd

4gb seg fixup, process tailwatchd (pid 2050), cs:ip 73:001d3b78

printk: 57 messages suppressed.

4gb seg fixup, process tailwatchd (pid 2050), cs:ip 73:001d3b78

printk: 56931 messages suppressed.

4gb seg fixup, process tailwatchd (pid 2050), cs:ip 73:001d3b78

printk: 57093 messages suppressed.

4gb seg fixup, process tailwatchd (pid 2050), cs:ip 73:001d3b78

printk: 114397 messages suppressed.

4gb seg fixup, process mysqld (pid 22760), cs:ip 73:00e6b4b5

printk: 23090 messages suppressed.

4gb seg fixup, process tailwatchd (pid 2050), cs:ip 73:001d3b78

printk: 99415 messages suppressed.

4gb seg fixup, process tailwatchd (pid 2050), cs:ip 73:001d3b78

printk: 57 messages suppressed.

the solution

mv /lib/tls /lib/tls.disabled mv /usr/lib/tls /usr/lib/tls.disabled echo hwcap 0 nosegneg > /etc/ld.so.conf.d/kernelcap-`uname -r`.conf ldconfig

reboot the server

reference: http://forum.lxcenter.org/index.php?t=msg&goto=42027&

xen slow network and packet dropped

http://xen.1045712.n5.nabble.com/Slow-network-solved-td2570997.html

finally :)

currently reading on:

http://www.howtoforge.com/perfect_setup_centos5.0

xen with PAE kernel

ayoyo..

cat /proc/meminfo

MemTotal: 2207744 kB

MemFree: 1227388 kB

it is4GB

http://www.howtoforge.com/make-your-xen-pae-kernel-work-with-more-than-4gb-ram-debian-etch-grub

will be updated later

check processor vt support

http://www.cyberciti.biz/faq/linux-xen-vmware-kvm-intel-vt-amd-v-support/

egrep ‘(vmx|svm)’ /proc/cpuinfo

this will show AMD or Intel VT support if available

update: http://www.howtogeek.com/howto/linux/linux-tip-how-to-tell-if-your-processor-supports-vt/

the error:

Alert: Could Not Start Vps, Reason: Error: HVM guest support is unavailable: is VT/AMD-V supported by your CPU and enabled in your BIOS?:

for intel

# grep --color vmx /proc/cpuinfo

for amd

grep --color svm /proc/cpuinfo

finally

cat /sys/hypervisor/properties/capabilities