Messages in this thread | | | Subject | Re: [RFC] [PATCH 00/13] Introduce task_pid api | From | Dave Hansen <> | Date | Tue, 15 Nov 2005 18:33:39 +0100 |
| |
On Tue, 2005-11-15 at 08:47 -0800, Greg KH wrote: > Why not just use Xen? It can handle process migration from one virtual > machine to another just fine.
Xen is relatively slow compared to the approach that we want to use. It's a pain in the neck to set up, especially if you want a _lot_ of partitions. We were going to try to compare the relative performance of the two approaches as as the number of vservers and Xen VMs is increased. We haven't found anyone brave enough to set up 100 Xen guests on a single system. :)
The overhead of storing the application snapshots that we're envisioning can be quite tiny compared to Xen. This becomes horribly important if you want to store the snapshots for a bit, and not simply keep one around for long enough to restore the image elsewhere.
Xen doesn't share Linux caches between partitions. So, as you increase the number of Xen partitions, the overhead of storing things like the '/' dentry goes up pretty linearly. Keeping only one Linux instance around makes such things much nicer to share.
The laundry-list of advantages is pretty long. This is starting to sound like a good OLS paper :)
-- Dave
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |