twg0214@uxa.cso.uiuc.edu (08/03/90)
HPFS and 640 Mbyte disk A number of articles on OS/2 1.2 stipulated that HPFS removed any disk size limits. Therefore, I did not hesitatate to buy a 386/33 clone with a 640 Mbyte ESDI disk. The disk was formatted as a single partition under DOS 4.01. However, OS/2 could not recognize the drive. The same was happening when I erased the DOS partition and attempted to create the HPFS partition. Then I read carefully a manual of my ESDI controller. It said that OS/2 can't recognize disks with more than 1024 cylinders which limits the size of the disk to about 508 Mbytes. After low-level format of my disk to 1024 cylinders (and losing 132 Mbytes) OS/2 installed nicely as either FAT or HPFS partition. Apparently, the 1024 cylinder limit is still in 1.2. Does anybody know if this limit will gone in 1.21 or 2.0? Ignacy Misztal ignacy@uiuc.edu
rommel@lan.informatik.tu-muenchen.dbp.de (Kai-Uwe Rommel) (08/05/90)
In article <135200001@uxa.cso.uiuc.edu> twg0214@uxa.cso.uiuc.edu writes: > >attempted to create the HPFS partition. Then I read carefully a manual >of my ESDI controller. It said that OS/2 can't recognize disks with more >than 1024 cylinders which limits the size of the disk to about 508 Mbytes. > >Ignacy Misztal >ignacy@uiuc.edu Most ESDI controllers provide some way of "remapping" of the disk cylinders to less than 1024 by increasing the number of sectors per track logically (inside the drive) to 63. This is transparent to the operating system and works with OS/2 too. I installed an NEC disk with 1224 cylinders and a NCL controller successfully using the remapping feature. Kai Uwe Rommel -- /* Kai Uwe Rommel * Munich * rommel@lan.informatik.tu-muenchen.dbp.de */
alistair@microsoft.UUCP (Alistair BANKS) (08/08/90)
In article <135200002@uxa.cso.uiuc.edu> twg0214@uxa.cso.uiuc.edu writes: > > >>Most ESDI controllers provide some way of "remapping" of the disk >>cylinders to less than 1024 by increasing the number of sectors per >>track logically (inside the drive) to 63. This is transparent to the >>operating system and works with OS/2 too. I installed an NEC disk with >>1224 cylinders and a NCL controller successfully using the remapping >>feature. > >This is true and my Ultrastor controller does the remapping, which helps >with disks up to around 508 Mbytes. For larger disks there is no help. >Alistair Banks from Microsoft sent me a message today writing that >the 1024 cylinder limit might be removed in 2.0. After receiving various mail on this subject & reading the postings I did some more checking. Apparently this is a disk driver question, not an OS/2 limit or HPFS question. The size that you list sounds like the common size which is the maximum you can map using existing AT definitions (1024 cylinders). If you write a disk driver which determines the size using a non-standard method, you can get past that. This has been done by one of the _major_ oems which is about to release its version of MS OS/2 1.21 - with HPFS support up to 1.2GB. The point is that you need their disk driver. Alistair Banks OS/2 Group Microsoft
dbc0027@cec1.wustl.edu (Daniel Bryan Crank) (09/10/90)
In article <135200001@uxa.cso.uiuc.edu> twg0214@uxa.cso.uiuc.edu writes: >A number of articles on OS/2 1.2 stipulated that HPFS removed any >disk size limits. Therefore, I did not hesitatate to buy a : >After low-level format of my disk to 1024 cylinders (and losing 132 Mbytes) >OS/2 installed nicely as either FAT or HPFS partition. Apparently, the >1024 cylinder limit is still in 1.2. Does anybody know if this limit will >gone in 1.21 or 2.0? I ran into a similar problem when attempting to set our network server up with a 360MB Maxtor Drive (1224 cylinders) and the existing Western Digital controller. We were able to _low-level_ format the entire thing, by using DOS's debug program to jump into the setup program on the controller card's ROM... (many, many thanks to Western Digital for helping us out -- they have the best technical support staff in the known universe). Anyway, the low-level format succeeded, but PMFDISK reported that the maximum partition size was just under 300MB, and nothing would change its mind. We wound up letting that extra 60-odd megabytes go in order to get the drive running...*sigh*. The people you should probably be talking to first are the manufacturers of the hard disk controller...especially if it's Western Digital :^) danno ------------------------------------------------------------------------------ | "Is that -- strictly speaking -- accurate, sir?" | YOYODYNE | | "Mansell, that is what we in the Royal Navy call a lie."|Propulsion Systems| | --Yellowbeard |Grover's Mill, NJ | | Email to dbc0027@cec1.wustl.edu (Top Secret Think Tank) |------------------|
rommel@lan.informatik.tu-muenchen.dbp.de (Kai-Uwe Rommel) (09/11/90)
In article <1990Sep10.152015.29987@cec1.wustl.edu> dbc0027@cec1.wustl.edu (Daniel Bryan Crank) writes: >with a 360MB Maxtor Drive (1224 cylinders) and the existing Western Digital >controller. We were able to _low-level_ format the entire thing, by using >DOS's debug program to jump into the setup program on the controller card's >ROM... (many, many thanks to Western Digital for helping us out -- they have >the best technical support staff in the known universe). > >Anyway, the low-level format succeeded, but PMFDISK reported that the maximum >partition size was just under 300MB, and nothing would change its mind. We >wound up letting that extra 60-odd megabytes go in order to get the drive >running...*sigh*. I have set up an ESDI disk for OS/2 with 1224 cylinders and *could* use all of the disk space. The trick was to use the controller's remapping feature which makes the disk appearing to have 63 sectors per track and 16 heads and the resulting number of cylinders. This was a NCL controller but I was told the WD-1007 is capable of this too. Kai Uwe Rommel -- /* Kai Uwe Rommel * Munich * rommel@lan.informatik.tu-muenchen.dbp.de */