On Thu, Jul 19, 2018 at 10:24 PM Richard W.M. Jones <rjo...@redhat.com> wrote:
> On Thu, Jul 19, 2018 at 09:50:00PM +0300, Nir Soffer wrote: > > On Mon, Jul 16, 2018 at 11:56 AM Daniel P. Berrangé <berra...@redhat.com > > > > wrote: > > ... > > > > > Recommendation is to run 'qemu-img info' to extract the metadata and > sanity > > > check results eg no backing file list, not unreasonable size, etc. When > > > running 'qemu-img info' apply process limits of 30 secs CPU time, and > 1 GB > > > address space. > > > > > > > Can you explain the values of cpu seconds and addres space? > > > > Also, I tried to use prlimit --rss=N, and the value seems to be ignored. > Is > > this > > a bug in prlimit? > > This is the code in OpenStack: > > > https://github.com/openstack/nova/blob/50f40854b04351fb622fd8b68b374a8fe8ca2070/nova/virt/images.py#L74 > > > https://github.com/openstack/oslo.concurrency/blob/a9d728b71e47540fd248a6bc2d301fdfa9a988ce/oslo_concurrency/processutils.py#L194 > (see prlimit) > Thanks for the links. The 30 seconds cpu_time time limit confuses me; it was added in: https://github.com/openstack/nova/commit/011ae614d5c5fb35b2e9c22a9c4c99158f6aee20 The patch references this bug: https://bugs.launchpad.net/nova/+bug/1705340 The bug show that qemu-img info took more then 8 seconds real time: /usr/lib/python2.7/site-packages/oslo_concurrency/processutils.py:355 2017-07-19 19:47:42.849 7 DEBUG oslo_concurrency.processutils [req-7ed3314d-1c11-4dd8-b612-f8d9c022417f ff236d57a57dd42cb5811c998e30fca1a76233873b9f08330f725fb639c8b025 9776d48734a24c23a4aef51cb78cc269 - - -] CMD "/usr/bin/python2 -m oslo_concurrency.prlimit --as=1073741824 --cpu=16 -- env LC_ALL=C LANG=C qemu-img info /var/lib/nova/instances/_base/41ebff725eab55d368f97bc79ddeea47df894145.part" returned: 0 in 8.639s execute How the size of the snapshot can slow down reading the qcow2 header? Is this relevant for qemu-img-rhev 2.10? Nir