> On 20 Nov 2022, at 18:51, D. Hugh Redelmeier <h...@mimosa.com> wrote: > > | From: Geoffrey Leach <geoffleach...@gmail.com> > > | Tip of the hat to whoever created the Fedora Live troubleshooting. It has > | (at least) gparted, fdisk, fsck, smartctl and badblocks. Seems like that > | should be enough for my purposes. (Aside from a hammer :-) > | > | Interestingly, the first three do not find any issues. badblocks froze the > | system. smartctl is running, so we'll see > > I'm not sure that there are any use-cases for badblocks(8) on a modern > disk. All modern disks want to handle bad blocks themseleves, behind > the scenes. > > When a bad block is detected during a write by the disk controller, it > maps the block to another block it takes from a pool of spares. There > are few ways to observe this: > > - one of the S.M.A.R.T. counts goes up > > - there may have been an extra bit of latency due to this procedure. > > When a bad block is detected during a read by the controller, it > retries in case that works. If so, it will remap the block on the > assumption that that the original block is no longer reliable. > If retrying fails, the drive reports that failure.
Mapping of bad blocks only happens on write. So multiple reads of a bad block will consistently fail. Barry > > Generally speaking, the correct things to do upon a real disk read > failure is: > > - backup your disks in case subsequent steps curdle your data. > > - determine what file-system structure just took a bullet. You might > have to recover from a backup. If the hit is to metadata, an fsck(8) > might be able to fix it. > > - after these forensics, write something to the bad block. The > controller will automatically remap the block. > _______________________________________________ > users mailing list -- users@lists.fedoraproject.org > To unsubscribe send an email to users-le...@lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org > Do not reply to spam, report it: > https://pagure.io/fedora-infrastructure/new_issue _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
