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: Command line used: time ./iozone -R -l 4 -u 4 -r 4k -s 100m -F (paths to four files in the ext4 filesystem) To be brief, I will show one time for each system, because the deviation is relatively small compared with the difference of timings between the two systems: Wheezy: 1m44.966s 0m0.208s 0m4.896s Jessie: 6m2.268s 0m0.456s 0m5.572s The benchmark results didn't show such a signifficant ratio and won't include them. Now I know this may not prove anything, but I didn't know how to produce proof. And also know that this is a rare and complicated setup, and that I should make a partition to compile, and all, but the point is, if it worked so well before, couldn't it perform as well in the new version? I hope you can solve this. Regards. -- System Information: Debian Release: jessie/sid APT prefers testing APT policy: (900, 'testing'), (500, 'testing-updates'), (500, 'stable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 3.14-1-amd64 (SMP w/4 CPU cores) Locale: LANG=es_AR.UTF-8, LC_CTYPE=es_AR.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Versions of packages qemu-utils depends on: ii libaio1 0.3.109-4 ii libc6 2.18-7 ii libcurl3-gnutls 7.37.0-1 ii libgcc1 1:4.9.0-4 ii libglib2.0-0 2.40.0-3 ii libiscsi2 1.11.0-4 ii libssh2-1 1.4.3-2 ii libuuid1 2.20.1-5.7 ii zlib1g 1:1.2.8.dfsg-1 Versions of packages qemu-utils recommends: ii sharutils 1:4.14-2 Versions of packages qemu-utils suggests: pn debootstrap <none> -- no debconf information -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
