Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE)

If you are receiving the following error in your logs while running a 32bit PAE Xen Kernel:

xen_net: Memory squeeze in netback driver

Then you need to do the following:

1. In your grub.conf (or other bootloader) set the Dom0 to a fixed size: dom0_mem=1024.

2. In /etc/xen/xend-config.sxp set dom0-min-mem to the same size as above.

3. Reboot

Basically what you are doing is ensuring that Dom0 will not be decreased in size, as when this happens it causes problems the the xen_net driver which can in turn cause network connectivity problems with your DomUs.

Related posts

• HyperVM: VM creation has failed. Reason: Could not download __path_program_ or no_template_and_could_not_download [] (0)
• Xen DomU: 4gb seg fixup, process (0)
• Where are the Xen log files? (0)
• Upgrading DomU Kernel HyperVM/Xen (0)
• HyperVM: Kernel image does not exist: /boot/hypervm-xen-vmlinuz (0)

Filed under: Uncategorized by — aaron @ 10:10 pm

Upgrading DomU Kernel HyperVM/Xen

First install both the Dom0 and DomU kernel by doing a yum upgrade.  Once you have done this, reboot the server into the new Dom0 kernel and run the following command (before you start each VPS on the server):

cd /usr/local/lxlabs/hypervm/httpdocs/; lphp.exe ../bin/misc/fixcentos5xen.php

Related posts

• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)
• Where are the Xen log files? (0)
• HyperVM: Kernel image does not exist: /boot/hypervm-xen-vmlinuz (0)
• HyperVM/Xen nash-hotplug using 100% of resources (Debian) (0)
• error: xenconsole: Could not open tty `/dev/pts/2′: No such file or directory (0)

Filed under: Uncategorized by — aaron @ 9:42 pm

lxadmin password not applying in HyperVM

If you get the following error in lxadmin when running HyperVM run the the command “/script/upcp” , reboot the VPS and try once again

“lxadmin  Your password is now set as a generic password which constitutes a grave security threat. Please change it immediately by  clicking here.”

Related posts

• Lxadmin Documentation and Useful Info (0)
• Xen DomU: 4gb seg fixup, process (0)
• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)
• Where are the Xen log files? (0)
• Upgrading DomU Kernel HyperVM/Xen (0)

Filed under: Uncategorized by — ijan @ 8:56 pm

Custom Kernel per VPS in HyperVM

To use a customer kernel per VPS in HyperVM, copy (or link) the kernel to  /boot/hypervm-xen-vmlinuz-vps.vm where vps is the name of the VPS.

Related posts

• Xen DomU: 4gb seg fixup, process (0)
• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)
• Where are the Xen log files? (0)
• Upgrading DomU Kernel HyperVM/Xen (0)
• linux-utils: update-rc.d: /etc/init.d/hwclock.sh: file does not exist (0)

Filed under: Uncategorized by — aaron @ 8:21 pm

HyperVM: cannot restore segment prot after reloc: Permission denied

Error:

Failed loading /usr/local/lxlabs/ext/lib/Zend/lib/Optimizer-2.5.7/php-5.2.x/ZendOptimizer.so:  /usr/local/lxlabs/ext/lib/Zend/lib/Optimizer-2.5.7/php-5.2.x/ZendOptimizer.so: cannot restore segment prot after reloc: Permission denied
Zend
2004072203214624464xù

Solution:

If you are receiving this error while installing HyperVM, then you need to disable selinux.  This can be done by changing it to disabled in /etc/selinux

Related posts

• Why don’t we use mod_python in a shared (cPanel) environment? (0)
• Where did netconfig go? (CentOS/RHEL) (0)
• What is xfs? (0)
• What is the pcscd? (0)
• What is rpcidmapd? (0)

Filed under: Uncategorized by — aaron @ 1:53 am

HyperVM: remote_authentication_failed / Can’t reset password in HyperVM

Error: HyperVM: remote_authentication_failed

If you are receiving this error, and HyperVM won’t reset the password on the slave server, you can manually do this on the slave server using the following commands:

# cd /usr/local/lxlabs/hypervm/httpdocs
# lphp.exe ../bin/common/resetpassword.php slave ‘password’

You then may need to force delete, and re-add the server with the new password.

Related posts

• linux-utils: update-rc.d: /etc/init.d/hwclock.sh: file does not exist (0)
• HyperVM: Kernel image does not exist: /boot/hypervm-xen-vmlinuz (0)
• Xen: Console Not working Ubuntu 7 (0)
• Xen DomU: 4gb seg fixup, process (0)
• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)

Filed under: Uncategorized by — aaron @ 12:16 am

HyperVM: Kernel image does not exist: /boot/hypervm-xen-vmlinuz

Error: HyperVM: Kernel image does not exist: /boot/hypervm-xen-vmlinuz

To fix this error, login to the HyperVM slave and run the following:

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

# lphp.exe ../bin/misc/fixfc6xen.php

Related posts

• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)
• Where are the Xen log files? (0)
• Upgrading DomU Kernel HyperVM/Xen (0)
• linux-utils: update-rc.d: /etc/init.d/hwclock.sh: file does not exist (0)
• HyperVM: remote_authentication_failed / Can’t reset password in HyperVM (0)

Filed under: Uncategorized by — aaron @ 7:59 am

linux-utils: update-rc.d: /etc/init.d/hwclock.sh: file does not exist

When installing software on Ubuntu on a Xen Virtual Server I encountered this error:

update-rc.d: /etc/init.d/hwclock.sh: file does not exist
dpkg: error processing util-linux (–configure):
subprocess post-installation script returned error exit status 1
Errors were encountered while processing:
util-linux
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install.  Trying to recover:
Setting up util-linux (2.12r-17ubuntu2.1) …
update-rc.d: /etc/init.d/hwclock.sh: file does not exist
dpkg: error processing util-linux (–configure):
subprocess post-installation script returned error exit status 1
Errors were encountered while processing:
util-linux

To fix this I did the following:

# touch /etc/init.d/hwclock.sh

Related posts

• Xen: Console Not working Ubuntu 7 (0)
• HyperVM: remote_authentication_failed / Can’t reset password in HyperVM (0)
• HyperVM: Kernel image does not exist: /boot/hypervm-xen-vmlinuz (0)
• Xen DomU: 4gb seg fixup, process (0)
• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)

Filed under: Uncategorized by — aaron @ 11:46 pm

HyperVM Error: sessionname_not_client []

If you are receive this error, you can check a number of ways to resolve it:

1. rm /usr/local/lxlabs/hypervm/session/*
2. Check / is not full on the server
3. chown lxlabs:lxlabs /usr/local/lxlabs/hypervm/session/

Related posts

• Where are the Xen log files? (0)
• error: xenconsole: Could not open tty `/dev/pts/2′: No such file or directory (0)
• HyperVM: VM creation has failed. Reason: Could not download __path_program_ or no_template_and_could_not_download [] (0)
• Xen DomU: 4gb seg fixup, process (0)
• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)

Filed under: Uncategorized by — aaron @ 8:07 pm

Xen DomU: 4gb seg fixup, process

A common error on a Xen DomU (as well as Dom0) in /var/log/messages once the guest/VDS has just been setup is:

4gb seg fixup, process

You can fix this easily by doing the following on the guest/VDS:

mv /lib/tls /lib/tls.disabled
mv /usr/lib/tls /usr/lib/tls.disabled
echo ‘hwcap 0 nosegneg’ > /etc/ld.so.conf.d/libc6-xen.conf
reboot

Related posts

• Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE) (0)
• HyperVM: VM creation has failed. Reason: Could not download __path_program_ or no_template_and_could_not_download [] (0)
• yum errror: error: install: %pre scriptlet failed (2), skipping … (0)
• Where are the Xen log files? (0)
• Upgrading DomU Kernel HyperVM/Xen (0)

Filed under: Uncategorized by — aaron @ 2:12 am