Shawn Leas wrote:
>
> On Sat, 8 Aug 1998, Terry L Ridder wrote:
>
> > > Think about it for two seconds. The devfs generates devices as needed.
> > > If you have a static /dev on a normal filesystem, you have to have
> > > all 8 million possible SCSI devices. With devfs, you don't.
>
> > I would like to understand why you make the statement above?
> > Why would I "have to have all 8 million possible SCSI devices"?
>
> Because with a non-DevFS, or, non-Automagic device node creation
> environment, you simply need the device nodes already there to support
> them.
Yes I do need devices nodes but only for the devices that I am using.
Albert's original statement was
<Begin Quote>
Think about it for two seconds. The devfs generates devices as needed.
If you have a static /dev on a normal filesystem, you have to have
all 8 million possible SCSI devices. With devfs, you don't.
<End Quote>
So let us look at Albert's statement.
The first part is:
"Think about it for two seconds. The devfs generates devices as needed."
I am also able to also create and remove device nodes as needed. I
either
use mknod or rm. I could also write scripts to do it if I was so
inclined.
I could also use /dev/MAKEDEV to create the new required entries, and
use
rm to remove entries that are no longer required. There are several
styles
by which I am able to manage the device nodes in /dev.
The second part is:
"If you have a static /dev on a normal filesystem, you have to have
all 8 million possible SCSI devices. With devfs, you don't."
Which is the part that I am asking Albert to explain. I explictly
asked him to explain the use of
"you have to have all 8 million possible SCSI devices."
I would maintain that I do not have to have any more SCSI devices
than I require/want/need, and that I do have the ability to manage
those devices myself. Therefore Albert's statement is false.
If I am planning my hardware configuration with proper care,
I make and delete device nodes as I require/want/desire.
If I have three SCSI drives with 4 primary partitions each all I need
is to ensure that the following are created in /dev.
0 brw-rw---- 1 root disk 8, 0 Aug 31 1996 /dev/sda
0 brw-rw---- 1 root disk 8, 1 Aug 31 1996 /dev/sda1
0 brw-rw---- 1 root disk 8, 2 Aug 31 1996 /dev/sda2
0 brw-rw---- 1 root disk 8, 3 Aug 31 1996 /dev/sda3
0 brw-rw---- 1 root disk 8, 4 Aug 31 1996 /dev/sda4
0 brw-rw---- 1 root disk 8, 16 Aug 31 1996 /dev/sdb
0 brw-rw---- 1 root disk 8, 17 Aug 31 1996 /dev/sdb1
0 brw-rw---- 1 root disk 8, 18 Aug 31 1996 /dev/sdb2
0 brw-rw---- 1 root disk 8, 19 Aug 31 1996 /dev/sdb3
0 brw-rw---- 1 root disk 8, 20 Aug 31 1996 /dev/sdb4
0 brw-rw---- 1 root disk 8, 32 Jun 30 1992 /dev/sdc
0 brw-rw---- 1 root disk 8, 33 Jun 30 1992 /dev/sdc1
0 brw-rw---- 1 root disk 8, 34 Jun 30 1992 /dev/sdc2
0 brw-rw---- 1 root disk 8, 35 Jun 30 1992 /dev/sdc3
0 brw-rw---- 1 root disk 8, 36 Jun 30 1992 /dev/sdc4
The entries /dev/sda, /dev/sdb, and /dev/sdc exist so that so
that if I need/want/desire to I am able to repartition the disks.
So I only need a total of 15 entries for the 3 SCSI drives with 4
primary
partition each.
If when I need to add a new drive at /dev/sdd, and again it has 4
primary
partitions I only need to create those 5 /dev/ entries.
The creation of those 5 entries may easily be accomplished with the
below
commands.
mknod /dev/sdd b 8 48; chown root:disk /dev/sdd; chmod 660 /dev/sdd
mknod /dev/sdd1 b 8 49; chown root:disk /dev/sdd1; chmod 660 /dev/sdd1
mknod /dev/sdd2 b 8 50; chown root:disk /dev/sdd2; chmod 660 /dev/sdd2
mknod /dev/sdd3 b 8 51; chown root:disk /dev/sdd3; chmod 660 /dev/sdd3
mknod /dev/sdd4 b 8 52; chown root:disk /dev/sdd4; chmod 660 /dev/sdd4
If instead I want to remove the hard drive which equates to /dev/sdb.
BTW I understand that the current hard drive which is currently /dev/sdc
will become /dev/sdb.
I make the necessary changes perhaps /etc/fstab may require changes.
Once the changes are made and the drive is removed I can easily issue
the command.
(cd /dev; rm -i sdc*)
and interactively remove those entries.
>
> Simple enough for ya? If not, you just don't understand and are proving
> yourself unworthy of discussing this any furthur, as you are unaware of
> the issues involved completely.
Your explanation is neither simple nor reasonable. Your answer is based
on emotions and your desire for personal attacks.
Neither Albert nor yourself have explained Albert's statement
<Begin quote>
If you have a static /dev on a normal filesystem, you have to have
all 8 million possible SCSI devices. With devfs, you don't.
<End quote>
I am fully aware of the issues involved.
Please see above comments concerning this statement.
>
> -Shawn
-- Terry L. Ridder Blue Danube Software (Blaue Donau Software) "We do not write software, we compose it."When the toast is burnt and all the milk has turned and Captain Crunch is waving farewell when the Big One finds you may this song remind you that they don't serve breakfast in hell ==Breakfast==Newsboys
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