On Sun 2013-06-23 12:19:40, Pavel Machek wrote: > Hi! > > This may very well be hw problem, but... > > I have error on sda4. I tried to make hdd reallocate it by writing > zeros there, but it will not. Is there special kind of write that > needs to be done to force reallocation? > > Would it be possible to indicate errors when writing to known-bad > sector? Uhuh. Seems like I have few consecutive bad sectors, and kernel is not willing to overwrite them in one pass...? root@amd:~# time cat /dev/zero > /dev/sda4 cat: write error: No space left on device real 9m47.083s user 0m0.264s sys 1m24.424s root@amd:~# time cat /dev/sda4 | wc -c cat: /dev/sda4: Input/output error 8959361024 real 5m9.784s user 0m0.544s sys 2m11.620s root@amd:~# time cat /dev/sda1 | wc -c 797852160 real 0m23.479s user 0m0.040s sys 0m5.492s root@amd:~# time cat /dev/zero > /dev/sda4 cat: write error: No space left on device real 7m51.619s user 0m0.460s sys 1m23.280s root@amd:~# time cat /dev/sda4 | wc -c cat: /dev/sda4: Input/output error 8958947328 real 5m25.973s user 0m0.564s sys 2m6.508s root@amd:~# ...Ok, lets try with dd. root@amd:~# dd if=/dev/sda4 of=/dev/zero bs=1 skip=8958947328 dd: reading `/dev/sda4': Input/output error 0+0 records in 0+0 records out 0 bytes (0 B) copied, 5.05805 s, 0.0 kB/s root@amd:~# dd if=/dev/sda4 of=/dev/zero bs=1 skip=8958947328 dd: reading `/dev/sda4': Input/output error 0+0 records in 0+0 records out 0 bytes (0 B) copied, 5.1051 s, 0.0 kB/s root@amd:~# dd if=/dev/zero of=/dev/sda4 bs=1 seek=8958947328 dd: writing `/dev/sda4': Input/output error 3585+0 records in 3584+0 records out 3584 bytes (3.6 kB) copied, 2.63182 s, 1.4 kB/s root@amd:~# ...at least errors are propagated to dd. Aha, bad idea, I need to do bigger block size so that I don't force reads...? Better, but still not good: root@amd:~# dd if=/dev/sda4 of=/dev/zero bs=4096 skip=$[8958947328/4096] dd: reading `/dev/sda4': Input/output error 0+0 records in 0+0 records out 0 bytes (0 B) copied, 5.12378 s, 0.0 kB/s root@amd:~# dd if=/dev/zero of=/dev/sda4 bs=4096 seek=$[8958947328/4096] dd: writing `/dev/sda4': No space left on device 1746674+0 records in 1746673+0 records out 7154376192 bytes (7.2 GB) copied, 219.494 s, 32.6 MB/s root@amd:~# dd if=/dev/sda4 of=/dev/zero bs=4096 skip=$[8958947328/4096] dd: reading `/dev/sda4': Input/output error 101+0 records in 101+0 records out 413696 bytes (414 kB) copied, 4.94643 s, 83.6 kB/s root@amd:~# Next try... root@amd:~# dd if=/dev/zero of=/dev/sda4 bs=4096 seek=$[8958947328/4096] dd: writing `/dev/sda4': No space left on device 1746674+0 records in 1746673+0 records out 7154376192 bytes (7.2 GB) copied, 241.291 s, 29.7 MB/s root@amd:~# sync root@amd:~# dd if=/dev/sda4 of=/dev/zero bs=4096 skip=$[8958947328/4096] dd: reading `/dev/sda4': Input/output error 102+0 records in 102+0 records out 417792 bytes (418 kB) copied, 12.4968 s, 33.4 kB/s root@amd:~# I don't think badblocks utility does what I need...? I tried re-running dd few time, even with conf=fsync; but 1) errors during write do not get reported 2) no more sectors are reallocated root@amd:~# dd if=/dev/zero of=/dev/sda4 bs=4096 seek=$[8958947328/4096] conv=fsync dd: writing `/dev/sda4': No space left on device 1746674+0 records in 1746673+0 records out 7154376192 bytes (7.2 GB) copied, 188.11 s, 38.0 MB/s root@amd:~# dd if=/dev/sda4 of=/dev/zero bs=4096 skip=$[8958947328/4096] dd: reading `/dev/sda4': Input/output error 102+0 records in 102+0 records out 417792 bytes (418 kB) copied, 6.20669 s, 67.3 kB/s root@amd:~# Any ideas? Thanks, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
