On 01/21/2015 08:45 PM, Kevin O'Gorman wrote:

On Wed, Jan 21, 2015 at 8:13 PM, Kevin O'Gorman <kogorman@gmail.com <mailto:kogorman@gmail.com>> wrote:

On Wed, Jan 21, 2015 at 7:27 PM, Joseph Loo <jloo20111002@gmail.com <mailto:jloo20111002@gmail.com>> wrote:

On 01/21/2015 06:53 PM, Kevin O'Gorman wrote:

I'm working with new 4TB drives, and one of them just had a bad spot in a fairly awkward place. The very first block of an ext4 partition was unreadable, and caused problems in booting, as well as anything else that wanted to scan partitions.

I overwrote the first 4K with zeroes, deleted the partition (with gdisk) and created a new unformatted partition to cover the area. Now that partition passes a read test, and I'm checking the other partitions.

The damaged partition has been inactive for a while, so I'm quite sure I have adequate backups. But now seems to be a time for me to learn -- lots of things have been going wrong, and I've been learning how to cope.

So I wonder if there's a way to get that partition back, at least in part, without using my backups.

Any hints, pointers, tutorials, or opinions welcome.

Have you tried doing a badblocks on the partition. This will try reading and writing data to the partition to check the disk drive. I generally do this on my drive before deploying. It tends to remove the bad blocks.

You can also try grc's Spinrite (cost money) at grc.com <http://grc.com>

--

I have not run it, but following the advice in its man page, I'll run e2fsck with the -c option on the two partitions that showed errors in ddrescue.

Bad blocks in an inode table. Yuck. Too many errors to make the partition recoverable I'll finish up with ddrescue... Sheesh!

Now the question is whether I can score a warranty return.

All the new drives have a lot of disk errors. The 750 GB drives and higher have higher error rates. The reason I do a badblock, is to exercise the drive and try to remove the bad blocks before they become a problem. The spare sectors on the drive will then replace the bad blocks thus saving the sector issue. badblocks probably will work but I found out that spinrite (all of them take a long time) seems to clean more of the errors before the drive starts showing problems. In the old days, the disk manufacturers use to do formats that clean out these problems. Another way of doing it is to use windows and do an ntfs full format. It too will try to remove all the bad blocks. The current drives do not do this. -- Joseph Loo jloo@acm.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org