All, I just ran a test against a IDE drive (/dev/sdb) and slightly older kernel (2.6.32). Similar to: dd if=/dev/sdb of=/dev/null conv=noerror,sync bs=4k With a good drive it ran fine. Then I used hdparm --make-bad-sector to intentionally corrupt a sector on the drive. When I re-ran it, /var/log/messages reported 10 bad logical blocks. And even worse, dd reported 20 bad blocks. I examined the data dd read and it had 80KB of zero'ed out data. So that's 160 sectors worth of data lost because of a single bad sector. At most I was expecting 4KB of zero'ed out data. I haven't started troubleshooting, but I want to know if this is expected behavior due to read-ahead or something. (Is there read-ahead on the raw device, or just if a file system is involved.) I can redo my test with 2.6.34 and get logs if that is a bug. And if not a bug, is there a hdparm command I can issue to eliminate this behaviour. Thanks Greg -- 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
