Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!pepper!cmcmanis From: cmcmanis%pepper@Sun.COM (Chuck McManis) Newsgroups: comp.sys.amiga Subject: Re: The secrets of the file system (was FillDisk) Message-ID: <35430@sun.uucp> Date: Thu, 3-Dec-87 12:06:54 EST Article-I.D.: sun.35430 Posted: Thu Dec 3 12:06:54 1987 Date-Received: Mon, 7-Dec-87 05:20:23 EST References: <6098@jade.BERKELEY.EDU> <2080@ulowell.cs.ulowell.edu> <2085@ulowell.cs.ulowell.edu> Sender: news@sun.uucp Reply-To: cmcmanis@sun.UUCP (Chuck McManis) Organization: Sun Microsystems, Mountain View Lines: 33 In article <2085@ulowell.cs.ulowell.edu> (Bob Page) writes: :I wrote in 2080@ulowell.cs.ulowell.edu: |>>You can force a disk validation by running DiskChange DH0: |> |>Arrgh! DON'T DO THIS unless the people who supply your |>harddisk.device (or whatever your driver is called) says it's OK! |> |>I realized DiskChange makes some NON-STANDARD calls to the driver. |>When I say non-standard, I mean IORequests that are not part of the |>basic and required functions for a device, like open, close, read, |>write, etc. Each device can have its own non-standard functions |>for special commands unique to that device. Actually, DiskChange never talks to the device directly. What it does is send an ACTION_INHIBIT(True) to the handler, which then takes the disk 'off line'. Then sends an ACTION_INHIBIT(False) to tell the handler 'you have a disk here now.' The handler will read in the root block, and if the BMVALID flag is not set, start the validator running on the disk. Therefore all disks can be 'DiskChanged'. If your disk reacts badly to this I would suggest either your driver is incorrectly written (very unlikely) or your hardware is broken. |>It may be that your driver writer also implemented the trackdisk's |>non-standard commands, but you DON'T KNOW what might happen when |>DiskChange says "MOTOR OFF" to your harddisk ... it might mean |>"FORMAT" to the driver! DiskChange should not be sending a MOTOR OFF command to the device, it shouldn't be talking to the device period, just the handler. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you.