Re: [libvirt] [PATCH] Add "io" option to virsh attach-disk sub-command.
On Tue, May 09, 2017 at 07:31:30AM -0700, Gordon Messmer wrote:
(Apparently I managed to screw up sending that, twice. Long
weekend.)
No problem. Your first posting got blocked into the moderator queue
since you weren't a subscriber. One of the list admins then approved
it, not realizing you had already subscribed to the list & resent the
patch
Please consider adding the option of setting the "io"
attribute when
attaching disks to guests. Under Red Hat (unsure if this is true under
vanilla libvirt), virt-install and virt-manager both default to explicitly
setting "io='native'" in the disk "driver" tag. virsh,
however, does not and
also does not provide an option to specify that setting at all. As a
result, disks use a different IO mechanism (the default, "threads") when
attached post-setup using virsh. Adding this option allows users to keep
disk performance consistent for disks attached at install, and those
attached afterward.
I think you can use the --iothread flag to "virsh attach-disk" to set
this parameter. virsh doesn't set it if not specified, since it tries
to avoid making policy decisions, like virt-manager/virt-install do
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|