[vpsFree.cz: community-list] QEMU IO performance

Mam dotaz ohledne QEMU IO vykonu, primo ve vps dostavam pri nasledujicim testu time dd if=/dev/zero of=/test oflag=direct bs=64k count=16000 nasledujici vysledek 16000+0 records in 16000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 4.11019 s, 255 MB/s real 0m4.112s user 0m0.012s sys 0m0.720s Nicmene kdyz to pustim v QEMU na disku typu raw, dostanu 16000+0 records in 16000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 13.6918 s, 76.6 MB/s real 0m4.112s user 0m0.012s sys 0m0.720s QEMU spoustim takto: qemu-system-x86_64 -cpu host -cdrom archlinux-2016.04.01-dual.iso -drive file=test,format=raw,cache=writeback -boot order=d -m 1024M -enable-kvm Disk je naformatovan primo uvnitr QEMU na ext4. Vykon je tedy vyrazne mensi nez primo ve VPS. Je to maximum, jak blizko se jde dostat? Nebo mam nekde chybu v tom, jak to pouzivam? Diky za pomoc, T. -- There are only two hard things in Computer Science: cache invalidation, naming things and off-by-one errors.