I was running down the open ovirt bugs, and notice this one,
which has an outlink to a post by you (Eric) on a mailing lsit
last month
And the following dependencies still open:
Bug 1041569 - [NFR] libvirt: Returning the watermark for all
the images opened for writing
https://www.redhat.com/archives/libvir-list/2014-August/msg00207.html
wherein you refer to a 'watermark'. To me as a non-lingo
aware (as to libvirt / libguestfs) developer, a watermark is a
pattern overlaid onto an image (a pattern placed on the glue
side of a postage stamp, or a 'DRAFT" notice on a document)
I _think_ you are referring to a 'high water mark' limit
which, if exceeded would result in content being lost (there
is mention of ENOSPC)
Is this accurate?
If so, isn't this information filesystem specific and so
something which the outsider 'container' cannot and should be
expected to reliably know? (I am thinking here of inode
exhaustion even when a Linux type FS seemingly has space per:
du ; the problem is worse with a 'sparse' capable filesystem
in play; and seems wholly unanswerable with a Windows FS or
some other variant)
I don't see how the hypervisor could accurately ever know this
without 'cracking open' and asking the inside tenant .. and
for privacy and data integrity / security reasons, the
hypervisor should not ever be doing this
Thanks
-- Russ herrold