Package: partclone Version: 0.2.73-2+b1 Severity: important Tags: upstream Dear Maintainer,
Program was started through Clonezilla with option to continue in case of read errors, since the goal was to replace an old disk that had a few damaged sectors. The block size was 4096 while the source and target disks both had 512 byte sectors. * What led up to the situation? After a read error of an odd number of sectors from the source disk, the copy process slowed down from above 100MB/s to about 10MB/s, and the "Current Block" output always presented odd numbers. Before the first read error, most of the time (70-80%) was in "wait", with a few percent system time and a few percent user time. After that read error, "wait" dropped to 0%, while system time climbed to about 85%. Running atop, the source disk shows 95% busy, and about 200000 reads/second. Average 0 kB/read (actually 512 byte/read). The destination disk shows 3% busy, and about 200 writes/second. Average 512 kB/write. So instead of just doing a few sector-sized (512-byte) transfers to properly align and then return back to the normal block sizes for the transfer, the program permanently switched to doing 512-byte reads. 4TB to copy at 100MB/s is about 12 hours. But with the ten-fold slowdown, it becomes 120 hours. * What outcome did you expect instead? I expected Partclone to be able to return back to 100MB/s or faster for the rest of the copy - the rest of the partition did not contain any damaged sectors. A few damaged sectors shouldn't bring the transfer to almost a stand- still. -- System Information: Debian Release: 8.1 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 3.16.0-4-amd64 (SMP w/1 CPU core) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages partclone depends on: ii e2fslibs 1.42.12-1.1 ii libblkid1 2.25.2-6 ii libc6 2.19-18 ii libcomerr2 1.42.12-1.1 ii libncursesw5 5.9+20140913-1+b1 ii libtinfo5 5.9+20140913-1+b1 ii libuuid1 2.25.2-6 ii ntfs-3g [libntfs-3g852] 1:2014.2.15AR.2-1+deb8u2 partclone recommends no packages. partclone suggests no packages. -- no debconf information
