On Fri, Dec 5, 2014 at 3:03 AM, Tomasz Chmielewski <t...@virtall.com> wrote: >> The first way to try to recover the current volume would be to >> overwrite LBA 2262535088 which you should only do with the filesystem >> unmounted. That's the sector causing the read error. If this is a 512 >> byte drive: >> >> dd if=/dev/zero of=/dev/sdb count=1 seek=2262535088 > > > It is a 512 byte drive. > > Unfortunately overwriting that fails - which is quite weird, given that > there are 0 reallocated sectors, according to SMART. > > Is there a way to determine what's stored there (i.e. if it's a file?). > > > # dd if=/dev/zero of=/dev/sdb count=1 seek=2262535088 > dd: writing to `/dev/sdb': Input/output error > 1+0 records in > 0+0 records out > 0 bytes (0 B) copied, 2.88439 s, 0.0 kB/s > > # dmesg -c > [ 8177.713212] ata4.00: exception Emask 0x0 SAct 0x400 SErr 0x0 action 0x0 > [ 8177.713285] ata4.00: irq_stat 0x40000008 > [ 8177.713349] ata4.00: failed command: READ FPDMA QUEUED
You're getting a read error when writing. This is expected when writing 512 bytes to a 4k sector. What do you get for parted /dev/sdb u s p -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
