Hi All,
We are setting up a system with a large number of very small
VMs for a project. We worked through a number of limitations, including those imposed
by blktap2 devices and the number of dynamic IRQ (set kernel config NR_CPUS)
etc. After these changes we were able to get to 154 domUs (!), but as
soon as we start up the 155th domU the system crashes. We edited
each domU config to have one blktap2 device (the disk image) and two virtual network
interfaces each.
We are using the standard XEN 4.0 (stable/release version) with
the 2.6.31.13 (pvops) kernel.
Attached is the output of /var/log/daemon.log and
/var/log/xen/xend.log, but as far as we can see we don’t quite know what
might be going causing the system to crash (no console access anymore and system
becomes unresponsive and needs to be power-cycled). I have pasted only
the relevant bits of information (the last domU that did successfully start and
the next one that failed). It may be the case that all the log messages weren’t
flushed before the system crashed…
Does anyone know where this limit of 155 domU is coming from
and how we can fix/increase it?
thanks
Yuvraj