Dear qemu experts, I recently ran qemu-img check on a large .qcow2 file, and got thousands (maybe millions) of output lines of the form:
Leaked cluster 12345678 refcount=3 reference=2 This seems like a bug in qemu-img check code, as repeating the same message for every cluster in a huge range is excessive and prevents terminal buffers from retaining earlier output that may or may not happen before this barrage of noise (rerunning the check with a grep filter showed a few ERRORs about clusters with reference > refcount, and a lot of other clusters with reference=0). Furthermore, the message seems to be factually incorrect, as a cluster with at least one actual reference is not "leaked", even if its reference count is higher than reality. I kind of suspect this to be related to lazy_refcounts in some way, but can't be sure. Running qemu-img 5.2.0 (plus Debian patches), trying to sanity check the backup of a large qcow2 file (> 400GB). Not using libvirt because I am not running a Red Hat system. P.S. My backup method may be somewhat wonky, but there are no clear instructions on how to backup a savevm state without stopping the virtual machine or redefining the host storage stack in weird ways. Enjoy Jakob -- Jakob Bohm, CIO, Partner, WiseMo A/S. https://www.wisemo.com Transformervej 29, 2860 Søborg, Denmark. Direct +45 31 13 16 10 This public discussion message is non-binding and may contain errors. WiseMo - Remote Service Management for PCs, Phones and Embedded