Date: Thu, 23 May 2019 08:43:47 -0700 From: Patrick Powell <papowell@astart.com> To: freebsd-scsi@freebsd.org Subject: Re: [Bug 202712] [cam] [ata] System doesn't recognize older hdd after boot Message-ID: <23f15e62-85e0-6196-fba1-adabfc3be416@astart.com> In-Reply-To: <bug-202712-5313-N2QMhI5OLe@https.bugs.freebsd.org/bugzilla/> References: <bug-202712-5313@https.bugs.freebsd.org/bugzilla/> <bug-202712-5313-N2QMhI5OLe@https.bugs.freebsd.org/bugzilla/>
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I appreciate the desire for legacy support, but re-adding (sp?) CHS support seems to be a bit silly. I tossed the last CHS drives in 2018 and they had not been powered up since 1999. If you are REALLY desperate for data recovery, then a Data Recovery outfit can do a sector by sector copy of the old CHS drive to a newer drive, or even a memory stick. You do not even need to have a functioning drive. Of course it may be a bit expensive... but if you need the data, cost may be irrelevant. On 2019-05-22 23:34, bugzilla-noreply@freebsd.org wrote: > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=202712 > > Scott Long <scottl@FreeBSD.org> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |scottl@FreeBSD.org > > --- Comment #39 from Scott Long <scottl@FreeBSD.org> --- > The code in sys/cam/ata is generic protocol and transport support for all > devices. The code in sys/dev/ata is controller-specific drivers. In simple > terms, adding CHS support would happen in sys/cam/ata. > > I have mixed feelings on adding CHS support. As others have mentioned, it's > ancient, and it's nearly impossible for people to test. It would exist as a > poorly tested codepath that would be prone to accidental breakage. The cost of > keeping it working, in terms of equipment procurement and operation, would > likely outweigh the benefit. > > It looks like Amazon has a PCIe add-in card for ATA/IDE, but I haven't owned a > working ATA drive in almost 10 years, and I probably haven't owned a functional > CHS-only drive in at least 20 years. I have no idea where I'd get one, other > than to buy batches of them off of Ebay and hope to find some that work. 20+ > years is a long time for a hard drive, even in the best of circumstances. > Moisture will invade the platter cavity through the breather hole. Lubrication > will slowly evaporate off of spindle and armature joints and redeposit itself > onto the platters and heads. Capacitors on the circuit board will slowly leak, > and copper and aluminum connectors and traces will corrode. I'm impressed that > you have a working 400MiB drive, that's a 25 year old drive at this point. I'd > worry that it would stop working in the near future. > > If I were to build a rig to operate a CHS-era IDE drive (or any ATA/IDE drive > for that matter), it would be solely to recover and archive the drive data to > modern storage. For that, I'd use software that supported the use-case. If > that means using an older version of FreeBSD, or using Linux, I'd do that. > It's such a niche use case that I'd spend considerably more time resurrecting > and testing CHS code than I'd spend actually recovering the data, and that's > just not an interesting use of my time. > > If there's community interest in supporting CHS long-term in FreeBSD, my > recommendation is to create a IDE-CHS specific transport in CAM that lives > alongside the ATA/SATA support, but does not rely on it. This probably means > copying sys/cam/ata/ata_xpt.c to sys/cam/ata/ide_xpt.c, removing the > SATA-specific logic in it, and adding in the IDE and CHS specific logic. Nice, > clean, and isolated so that it's less likely to be accidentally broken, and > people working on SATA aren't likely to trip on it. This would probably be a > week of work at most, assuming that test hardware is available. > -- Patrick Powell Astart Technologies papowell@astart.com 1509 Hollow Ct., Network and System San Diego, CA 92019 Consulting Cell 858-518-7581 FAX 858-751-2435 Web: papowell at astart dot com
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