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Installing udev in VE based on Debian-4.0
From OpenVZ Wiki
When you install the udev package in VE based on Debian-4.0 template, you can may the following message:
Setting up udev (0.105-4) ... /var/lib/dpkg/info/udev.postinst: line 125: echo: write error: Operation not permitted
The problem is that postinstall script tries to write to /proc/sys/kernel/hotplug file, and this operation is prohibited in a VE. To work around this problem, just comment the 125th line in /var/lib/dpkg/info/udev.postinst file, that writes to the /proc/sys/kernel/hotplug file. After that udev can be installed smoothly.
P.S. Don't forget to enable the sysfs feature for the VE in question (by vzctl), in order for udev to be able to work.
vzctl set XXX --features "sysfs:on" --save
