Control: tag -1 + moreinfo 31.05.2014 02:23, Ernesto wrote: > Package: qemu-utils > Version: 2.0.0+dfsg-4+b1 > Severity: normal > > Dear Maintainer, > > I use qemu-nbd to mount a ext4 filesystem from a virtual disk image which is > stored in an NTFS partition. I have more space in the NTFS partition than in > my native-linux ones, but I need ext4, so this is a good solution. > > I use the virtual disk to compile source code, which grows up to 8-9 GB. I > mount it with: > > modprobe nbd && qemu-nbd -c /dev/nbd0 /path_to_image/trunk.qcow2 && mount > /dev/nbd0 /path_to_mountpoint/mnt/ > > I used to have this setup on a Wheezy system, and its performance was very > good. Now, I upgraded to Jessie, and the same setup performs poorly. I ran > iozone disk benchmark on both systems, several times, over the ext4 > filesystem in the virtual disk:
I already told you that what you use makes very little sense. Now with this setup, you have at least 2 main components involved: the kernel and qemu-nbd. If you want this bugreport to go _anywhere_ instead of just being ignored, please try keeping one of the 2 components the same and changing another. I mean, run wheezy kernel and qemu-nbd ver. 2.0 and see how it performs - this keeps kernel unchanged but changes qemu-nbd. Run jessie kernel and try two versions of qemu-nbd - this will keep kernel unchanged at other version but changes qemu-nbd. If, when running the same kernel, by changing qemu-nbd you can reproduce the slowdown, in both cases, it will mean it's something in qemu-nbd. If speed drops when you change kernel, it must be kernel. Or just get life and get a real setup instead of spending more time on this. Thanks, /mjt -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
