* Richard W. M. Jones: > I tested the speed of decompression using: > > $ hyperfine 'qemu-img convert -W -m 16 -f qcow2 test.qcow2.XXX -O raw > test.out' > (qemu 8.0.0-4.fc39.x86_64) > > $ hyperfine 'nbdkit -U - --filter=qcow2dec file test.qcow2.XXX --run > '\''nbdcopy --request-size "$uri" test.out'\'' ' > (nbdkit-1.35.11-2.fc40.x86_64)
How realistic is that? Larger cluster sizes will make random access perform noticeably worse is some cases. Think about reading a few bytes towards the end of the cluster. It makes a difference whether you have to decompress 64 KiB bytes for that, or 2 MiB. As far as I understand it, the above commands use all data decompressed, so they don't suffer from this issue (particularly with read-ahead to deal with unfortunate cluster boundaries). Time to first HTTP request served after boot or something like that might be a better comparison. Thanks, Florian _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
