Date: Thu, 23 May 2019 06:34:23 +0000 From: bugzilla-noreply@freebsd.org To: scsi@FreeBSD.org Subject: [Bug 202712] [cam] [ata] System doesn't recognize older hdd after boot Message-ID: <bug-202712-5313-N2QMhI5OLe@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-202712-5313@https.bugs.freebsd.org/bugzilla/> References: <bug-202712-5313@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D202712 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 cos= t 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 owne= d a working ATA drive in almost 10 years, and I probably haven't owned a functi= onal CHS-only drive in at least 20 years. I have no idea where I'd get one, ot= her than to buy batches of them off of Ebay and hope to find some that work. 2= 0+ years is a long time for a hard drive, even in the best of circumstances.=20 Moisture will invade the platter cavity through the breather hole. Lubrica= tion will slowly evaporate off of spindle and armature joints and redeposit itse= lf onto the platters and heads. Capacitors on the circuit board will slowly l= eak, 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 dri= ve 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.= =20 It's such a niche use case that I'd spend considerably more time resurrecti= ng 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 mea= ns 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. N= ice, 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. --=20 You are receiving this mail because: You are the assignee for the bug.=
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