[pve-devel] mass deployment for testing ipcc_send_rec failed

[Daniel Hunsaker]

> > seems like that - yes. But do you know why this happens? it happens
already
> > starting 15 vms in parallel while everything is idle.
>
> That is quite normal behavior.
>
There's a lot that goes on when starting a VM, and it consumes resources
like crazy.  Each VM (once the KVM process starts up) has to create all of
its virtual hardware, initialize it, and start the boot process.  That
involves a lot of disk activity, since the virtual devices need to be
loaded individually, and the boot data is also not only stored on disk, but
frequently inside a virtual disk file.  There's a lot of other stuff
happening, too, but these are the main resource hogs.

The process tends to be pretty quick most of the time, so it may not
register on load averages (and I/O wait doesn't always show in load
averages anyway), but it gets pretty intense.  So it's perfectly normal
behavior that makes a lot of sense.  Containers will be somewhat less
demanding, due to their nature, so you might be able to start more of them
at once, but there will still be limits even there.  This is why the
on-boot VM startup process works the way it does.  I forget where that
logic is stored, but that approach would probably be your best bet, at
least until the changes Dietmar mentioned earlier can be merged and
released.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.proxmox.com/pipermail/pve-devel/attachments/20140528/be8f5f0f/attachment.htm>