Aggressively fsck a disk before install

Question

I have an old HP Athlon machine I use for testing software under the old processor. We have frequent brown outs, and after the last one the disk was a mess. It was so bad I could not run fsck and dispatch all the problems. I performed a fresh install of the OS, but I'm still getting fsck complaints.

I'd like to try one last time to reload Linux before condemning the hard drive or machine. After the filesystem is created but before the install occurs, I'd like an aggressive fsck performed to mark suspect blocks as bad.

The disk is large (about 500 GB) and a Debian 8 distro is relatively small (8-12 GB is usually more than enough), so I don't care if good blocks get marked as bad. I also like the GUI install, but I'm not married to it.

I have two questions:

1. Does Debian 8 provide a choice to perform an fsck before installing the base system? If so, where is it? If not, then what is the process?

2. Does fsck have a setting to control how aggressively blocks are marked as bad? If so, what is it? If not, then what can be used?

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EDIT: the machine is an HP5850. Entering the BIOS, navigating to Storage and then Drive Protection System (DPS) Self-test resulted in DPS recommending replace the drive. DPS did not provide any statistics, so I'm not sure the extent of the damage.

Considering I can purchase an [old] new SATA II drive for $12 USD, I'm just going to replace it. There's no sense in wasting time or energy on it.

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The related references are as follows. Neither question appears to be addressed.

• fsck man page
• Chapter 6. Using the Debian Installer | 6.3. Using Individual Components

Answer 1

1. "Does Debian 8 provide a choice to perform an fsck before installing the base system? If so, where is it? If not, then what is the process?"

   As an alternative, first download and burn a GPartEd CD (or write to a thumb drive). Before running the installer, boot GPartEd and partition the disk to your liking and run fsck or just run badblocks at length.

   When you run the Debian installer, just tell it how to use the partitions that are there. The installer does not need to create its own partitions. It is perfectly happy to use existing partitions.

2. "Does fsck have a setting to control how aggressively blocks are marked as bad? If so, what is it? If not, then what can be used?"

   The -c option to e2fsck causes it to run the badblocks program to scan for bad blocks. You can run badblocks directly as well. By default, badblocks does a read-only test. To be more aggressive, you can specify -n for a non-destructive read-write test. You can also set the -p option to increase the number of passes that it makes.

   You may want to run badblocks before you partition. That way, you can specify the faster -w write-only test.

Answer 2

If you are getting fsck errors that often, the drive may as well be coughing up blood. Even if you mark every single bad block as bad, it won't be long before more blocks go bad. I would imagine you could change into another tty to do an fsck if you really need to (Ctrl + alt + F2 to switch to tty2), but I can't emphasize enough how much you need a new hard drive if what you are saying is accurate.

Answer 3

1. No, and I don't think it's worth it. Fsck (as implemented by most filesystems) does not check your drives. It validates the filesystem metadata and makes sure the view is consistent when you mount them. It doesn't make much sense to do it before installation, because by definition, you'll only have empty space.

2. Use badblocks instead. If you want to make sure your data doesn't rot, use a filesystem which supports scrubbing. Lvm itself can do it too.

Answer 4

To check a modern disk for reliability, consider using the built in tests; you can trigger them with the smartctl utility, eg:

smartctl -t long /dev/sdx
#wait an hour or two
smartctl -a /dev/sdx
#should have recorded a result in the self-test log

If you want to make sure beforehand that everything has recently been written to, in order to discover sectors that will not write properly, you could overwrite the whole medium with something like a dd from /dev/urandom, or shred with one of the randomizing options.

Answer 5

I would recommend getting the manufacturer's low-level format software (if any exists) which may only run on Windows (or if you're lucky, from a bootable CD/DVD/USB for which you'd download an image from their website). If you have sufficient control over the operation to reduce the reported capacity of the drive in exchange for a much larger spare sector pool, you should do so, in anticipation of many of those spares being substituted as you test the drive as @rackandboneman has suggested. Far better to have a 400- or 450-GB drive with all bad sectors swapped for spares and more left for future defects, than to exhaust the spare pool and have future bad sectors that can't be transparently remapped.

Answer 6

Some basic things if you don't have fancier tools available (eg it's a USB disc and SMART doesn't work):

dd if=/dev/sdX of=/dev/null bs=1M

will read all of the disc. You'll see in the dmesg log if there are sectors which couldn't be read. Though it won't tell you if it managed to read them after retries. It's not as good as badblocks but I mention it for its ubiquity.

If you have bad sectors and you don't want anything on the disc:

dd if=/dev/zero of=/dev/sdX bs=1M

will cause all the blocks to be rewritten. If there are sectors which are unreadable, this should cause them to be swapped with sectors in the reallocated pool and become usable again.

If you have a disc where reallocation is happening then the disc is on the way out. I wouldn't use it for anything important, but sometimes you have data you don't care that much about and it might be OK for that.

If it's an SSD then things are different and these don't apply.