Date: Tue, 20 Sep 2022 01:45:55 -0400 From: grarpamp <grarpamp@gmail.com> To: freebsd-questions@freebsd.org Subject: Re: disk non-destructive bad-block write/fix? Message-ID: <CAD2Ti28Bdm9kZq5umziXPizMXQdV5LZkYixogWmR0=6CBaM11w@mail.gmail.com> In-Reply-To: <d687eb29-a3fb-7d91-a2c6-c1e4e1dc7e31@dreamchaser.org> References: <d687eb29-a3fb-7d91-a2c6-c1e4e1dc7e31@dreamchaser.org>
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> throwing a lot of errors USB... reseat cables. > Is there a way to exercise the free blocks on a ufs disk and move all > defective ones to the bad-block list? That's function of the hw, not the fs. If you want to nuke the fs and do that to the disk dd if=/dev/urandom of=/dev/da0 bs=1m If not, then you can pray to hit most of the fs data areas with dd if=/dev/urandom of=/mnt/bigrandfile bs=1m but that's a prayer. Better to buy enough media to have backups of backups. > Or is that already happening in the above scenario? Yes most firmwares modepages are set to automatically write-reallocate, you can fiddle those using the scsi/ata/usb spec and camcontrol. Store a sha256 of all the files, read them back to verify and compare to that. > The disk is about 40% full There's probably not a shrinkfs, and without checking where those existing extents are, attempting to create a tailing 60% fs to move the 40% into to write-realloc it... could end up footshot. > wondering if the whole rest of it is trashed dd if=/dev/da0 of=/dev/null bs=1m conv=noerror But that's only a read test, not a write test.
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