XEN, Can't create more DomU, run out of resources??

HellSpawn · 08-12-2008, 03:00 PM

Hello,

I have Xen 3.2 on gentoo running on a Dell PowerEdge R900 with 132GB of RAM and 16 2.93GHz X7350 Cores

I have bridging:

Code:

bridge name     bridge id               STP enabled     interfaces
eth1            8000.0015175e0a11       no              peth1
                                                        vif1.0
                                                        etc...

I use LVM to hold a the virtual disk of all the virtual servers.

Right now I have 69 DomU running on this server, and when I try to create one more I get these errors from the new DomU console:

Code:

XENBUS: Timeout connecting to device: device/vbd/2049 (state 6)
XENBUS: Timeout connecting to device: device/vbd/2050 (state 6)
XENBUS: Device with no driver: device/vif/0
XENBUS: Device with no driver: device/console/0
VFS: Cannot open root device "sda1" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

I still have over 50GB of free RAM, and I have assigned Dom0 2GB.

I think I ran out of resources (maybe IRQs, don't really know) but don't know how to assign more or just make it work so I can create more virtual servers.

Any ideas on how to fix this?? Did I hit a wall here?? Should I move to something like VServer instead??

Thanks for any help.

bsdxlr8r · 09-15-2008, 08:10 AM

yes. i think you hit a wall. Xen has it's limits on how many guests (DomU's) a Dom0 on a same physical host can have...and i think you found it.
As for your wanting to try another virtualization means; some other semi-open, semi-free, open, free and even proprietary virtualization means use xen's hypervisor. this, i believe is where the pertinant restrictions come from.

I am no xen expert or virtualization expert, but i believe what i tell you to be 100% true (based on what i've learned through my use of xen, it's alternatives and attending it's competitor's conferences).

sure, there may be an alternative that i am not aware of at the moment, but i doubt it would be a viable option due to drawbacks that I, myself would not be willing to accept in most cases...(bad loss of 30 customer servers on a virtuosso system comes to mind).

HellSpawn · 09-15-2008, 10:25 AM

Thanks,

I guess I'll just get a new server for new virtual servers, and just assign more resources to the old virtual ones on the other server so they run better then.