Date: Wed, 17 Feb 2021 14:22:04 -0500 From: Ira Cooper <ira@wakeful.net> To: Ravi Pokala <rpokala@freebsd.org> Cc: "freebsd-fs@freebsd.org" <freebsd-fs@freebsd.org> Subject: Re: Simulating bad sectors on file based storage device. How? Message-ID: <CAAPGDwJ3AVGk6jLrvhytj%2BGvAvfkwwZDG8-b4kKdgA7XLy4kZg@mail.gmail.com> In-Reply-To: <7DBD44C9-AB81-43AB-94C9-212577A765B3@panasas.com>
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A suggestion: Use ISCSI to emulate the SCSI layer, and use the target to emulate the errors you want to emulate. I believe the ports collection has at least one userland target in it. -Ira On Wed, Feb 17, 2021 at 2:02 PM Ravi Pokala <rpokala@freebsd.org> wrote: > -----Original Message----- > Date: Tue, 16 Feb 2021 16:05:03 +0300 > From: Artem Kuchin <artem@artem.ru> > To: Alan Somers <asomers@freebsd.org> > Cc: freebsd-fs <freebsd-fs@freebsd.org> > Subject: Re: Simulating bad sectors on file based storage device. How? > Message-ID: <46b52475-385f-5931-f425-fd546dd5b377@artem.ru> > Content-Type: text/plain; charset=utf-8; format=flowed > > gnope only allows to set probability, but i need an exact block in an > exact place. > > ATA, NVMe, and SCSI all have commands to mark specific ranges of logical > sectors as unreadable. > > - ATA: WRITE_UNCORRECTABLE_EXT (has both report-failure-instantly and > perform-real-error-recovery-before-reporting-failure modes) > > - NVMe: Write Uncorrectable > > - SCSI: WRITE_LONG (has both report-failure-instantly and > perform-real-error-recovery-before-reporting-failure modes) > > The base system does not contain programs to issue those commands > specifically, but the commands can be assembled by hand and sent to the > drive via `camcontrol cmd' (ATA, SCSI) or `nvmecontrol io-passthru' (NVMe). > Obviously, assembling those commands would require spending some time with > the ATA specs from t13.org, the NVMe specs from nvme.org, or the SCSI > "Block Commands" spec from t10.org. > > It should go without saying that those commands are dangerous, because by > definition they destroy data. Use with caution after deep study of the docs > in question. > > -Ravi (rpokala@) > > > 15.02.2021 20:44, Alan Somers ?????: > > If you have SCSI disks, you can inject errors with `sysctl > > kern.cam.da.0.error_inject`.? If not, you can use gnop(8) to > simulate > > a flaky disk. > > > > On Mon, Feb 15, 2021 at 10:36 AM Artem Kuchin <artem@artem.ru > > <mailto:artem@artem.ru>> wrote: > > > > Hello! > > > > Is there a way to build a file base storage device (for example, > file > > based zfs mirror) and then simulate a bad sector for one of the > > mirror > > sides? > > > > Artem > > > > _______________________________________________ > freebsd-fs@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" >help
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