cs161agc@sdcc10.ucsd.EDU (John Schultz) (12/13/88)
I recently received Supramount 5.1 and reformated my drive for the
FFS. The performance increase is excellent, but:
Supra states that you must use their supramount program, because
the drive info is written to the harddrive (cyl 0). Furthermore,
they state that supramount installs an "interrupt" to "talk to the
fast file system for sync purposes". They state that the drive
cannot be mounted using Mount and a mountlist, due to the previous
constraints. I asked why this was so, and was told that the
developer for their software "didn't know what was going on", and
they have since moved development in-house. New software "should be
available in about a month, correcting these problems". Other
problems include [Supra please fix]:
1. approximately 200,000 bytes are used as buffers when using
supramount. There is no way to change this. That's about 50k per
partition.
2. Reboot times are slow, due to the fact that supramount re-runs
_itself_ and has to reload l:FastFileSystem (12k) for each partition.
Task supramount (11k) stays resident. We used db and found that it
just sits there, waiting for a signal.
3. Cylinders 1-6 are wasted. Why not put more drive info on these
tracks, like FastFileSystem, scsidisk.device, where supramount runs
and then _never_ accesses the floppies again.
4. The 4.9% increase in space is not evident, perhaps because of
3.
In an attempt to increase reboot times I set up mountlist entries,
getting lowcyl, highcyl, etc from the supraformat program. I mounted
dh0: as "mount dh0:" and it worked. I did the same for dh1-dh3,
They all worked fine. I also set up buffers to 5 and saved about
100k. Here is the mountlist entry for dh0: that I used:
; entry for a non-autobooting A1000, with a 20meg miniscribe:
DH0: Device = harddisk.device ; or scsidisk.device
Unit = 1
Flags = 0
Surfaces = 4 ; 20meg miniscribe
BlocksPerTrack = 17 ; ...
Reserved = 1 ; should this be 0,1, or 2? (noboot)
Interleave = 0
LowCyl = 7 ; get these from supraformat
HighCyl = 156 ; ....
Buffers = 5
StackSize = 4000
GlobVec = 1
FileSystem = l:FastFileSystem
DosType = 0x444F5301
#
dh1-dh3 differ only in lowcyl and highcyl. The goal here is to
mount dh0:, then immediately transfer control to it to continue the
startup sequence, so s/startup-sequence on the floppy is:
mount dh0:
dh0:c/makedir ram:t
dh0:c/assign t: ram:t ; so the next script is faster
dh0:c/execute dh0:s/hdstartup
Where hdstartup mounts dh1-dh3, vd0:, etc. Why not use rad:? 'cause
a 100k rad is needed for all the necessary boot files. Setting the
rad bootpri to 127, you can boot off of rad, even with bootable
floppies, but the drives are still accessed. Furthermore, rad and
vd0 don't get along.
Anyone else tried this approach? Did it work? (yeah, Supra says
it won't work, but it does for my system). What should "Reserved" be
set to in the mountlist? The docs say 2, what about non-bootable
disks? I haven't tried writing to the drive when mounting with
mountlist, any danger of toasting a partition with improper
mountlist entries?
Any inputs appreciated,
John Schultzcs161agc@sdcc10.ucsd.EDU (John Schultz) (12/13/88)
I just tried writing to the harddisk with reserved = 1 and it blew away kickstart. So I set it to 2, it works fine, set it to 0, it went out to la-la land, had to turn of the harddrive. The scsidisk.device seems to work as well. Even though it doesn't boot, reserved must be 2. (Just like the 1.3 docs say, gee! Still don't know why, though...) John Schultz