[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] Multiple priviliged domains

Ian Pratt wrote:
3. I don't seem to be able to create more than 8 VBDs. [I am using xen-2.0.1-src.tgz.] While trying to start 5 domains, each of which had two "scsi" disks (/ and swap), I discovered that the 5th domain wouldn't start until I removed the swap disks from both the 4th and 5th domains' configuration files -- i.e., not exceeding 8 VBDs total. A cursory search through the code didn't reveal any relevant #define's, and I didn't see anything about this in the Xen docs, so before I look further I thought I'd ask the list if this is a known limit. (If so, I am surprised the VBD structures aren't allocated dynamically to prevent this?) A search of the mailing list revealed a message from Ian on 2004-03-10 stating "Mark wrote a pretty good readme on VBDs and put it in the tree", but I couldn't find the readme; is it still part of the tree?

Are you using loop files? If so, Linux has a statically compiled
allocation, set to 8 by default. Fixing this and submitting the
patch to lkml would a good thing...

I don't believe the VBD code has any such limitations. (We tend
to use LVM rather than loop files).

If you use files as backend for VBDs in domain0, you use loop device. If the CONFIG_BLK_DEV_LOOP in dom0 kernel is compiled as module, you can use max_loop parameter while doing modprobe/insmod. And if it's compiled directly into the kernel, use max_loop=n boot option.


cd /local/pub && more beer > /dev/mouth

SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/
Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.