Date: Tue, 9 Jul 2002 20:56:41 -0400 (EDT) From: Chuck Robey <chuckr@chuckr.org> To: Don Lewis <dl-freebsd@catspoiler.org> Cc: <peter@wemm.org>, <julian@elischer.org>, <hackers@jnielsen.net>, <hackers@FreeBSD.ORG> Subject: Re: offtopic: low level format of IDE drive. Message-ID: <20020709205446.E945-100000@april.chuckr.org> In-Reply-To: <200207091029.g69ATLwr003533@gw.catspoiler.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 9 Jul 2002, Don Lewis wrote: > On 8 Jul, Peter Wemm wrote: > > Julian Elischer wrote: > >> this is not a 'reformat' > >> > >> what I want to do is an old-fashionned refomat/verify where the controller > >> writes new track headers etc. > > > > The thing is, just about all IDE drives more than a few GB or so do 'track > > writing' and have no fixed sectoring or sector positioning. ie: each time > > you write a single sector to a track, it does a read-modify-write of *THE > > ENTIRE TRACK*. This is why we have to have write caching turned on for IDE > > drives to get decent performance. Without it, it essentially rewrites the > > entire track over and over and over again because it cannot fill its write > > buffer in order to write a contiguous block to completely replace what was > > there before. ie: each track is one giant physical sector with multiple logical > > sectors inside it. > > > > The really annoying thing is that most newer scsi drives do this too. > > How readily available is the information about which drives do this? As > someone who only buys the occasional drive, I'd rather not have to buy > one and do the evaluation myself using the method mentioned later in > this thread. > > > > Get a UPS if you value the data. :-] > > That doesn't help if the cat knocks a book off the shelf onto the power > switch, or if you trip over the cord between the UPS and the computer, > or if the magic smoke escapes from the computer power supply. I've seen some BIOSes that allowed you to force the low-level format. Alternatively, you could run an old copy of dos that had "debug" on it and tell it to "g c800:0" which was the address of the disk ROM routine; it worked very reliably for me (before I learned about scsi disks!) > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message > ---------------------------------------------------------------------------- Chuck Robey | Interests include C & Java programming, FreeBSD, chuckr@chuckr.org | electronics, communications, and signal processing. New Year's Resolution: I will not sphroxify gullible people into looking up fictitious words in the dictionary. ---------------------------------------------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020709205446.E945-100000>