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Large Floppy Support Discussion - USBMSD.ADD
Andreas Kohl:
--- Quote from: Valery Sedletski on November 27, 2017, 05:14:25 pm ---it supports only very old ex2fs version, and does not mount newer ones. Yes, there are some problems with LVM. It works fine with danidasd.dmd. I don't know, where are incompatibilities with LVM. Probably, it is not ext2-os2.ifs itself is incompatible with LVM, but it is mwdd32.sys driver, which it is based on. Need to look at it better. Possibly, we'll just need to update mwdd32.sys.
--- End quote ---
There are two different cases on LVM-enabled OS/2 systems. The orignal LVM partition support introduced by WSEB and the later CP1/CP2. It was enhanced in 2002 by the Extended Partition (EXPART) support to address larger hard drives and additional partition IDs (but only for uniprocessor ACP1/ACP2). The MWDD32.SYS based IFS implementations predate these developments. On non-LVM enabled systems the corresponding filter drivers ext2flt.flt or hfs.flt can still be used for recognition.
Valery Sedletski:
2Andreas Kohl:
> I'm aware of the limitations. Fortunately Валерий wrote elaborately about it, so I have nothing to add. Большое спасибо! Oчень эрудированнo.
Danke schoen :) (I know German a bit too :) Studied it at school.)
> There are two different cases on LVM-enabled OS/2 systems. The orignal LVM partition support introduced by WSEB and the later CP1/CP2. It was enhanced in 2002 by the Extended Partition (EXPART) support to address larger hard drives and additional partition IDs (but only for uniprocessor ACP1/ACP2). The MWDD32.SYS based IFS implementations predate these developments. On non-LVM enabled systems the corresponding filter drivers ext2flt.flt or hfs.flt can still be used for recognition.
Expart? Do you mean, partfilt.flt/ext2flt.flt? The second one was created for ext2-os2.ifs. The 1st one was its enhanced version for fat32.ifs, to support additional partition types, by default. They could be added with "/p" switch too. hfsflt.flt is a filter from hfs.ifs (Macintosh HFS file system for OS/2). It has nothing to do with partition types. It is needed for Macintosh floppies. They have no BPB, which is required for OS/2. So, this filter creates a virtual BPB on the fly, which makes OS/2 happy with these floppies. Why only uniprocessor ACP1/ACP2? partfilt.flt has some problems with SMP?
Or expart is something like partfilt.flt/ext2flt.flt, but for LVM systems? AFAIK, for LVM systems, such support is unneeded, because you can create the LVM info for any partition type, and the kernel will call all IFS'es for that partition, and it will be mounted if some IFS will recognize it. Or not all partition types are supported? 0x7/0xb/0xc supported, but Linux 0x83 is not? I am not sure. It is possible, indeed...
If so, it is also possible to assign a 0x7 partition type to an ext2 partition. Linux does not care about partition types, so it would not hurt it. So, we can try testing it.
Andreas Kohl:
Actually I'm only 1/4 немецкий but 3/4 германский. I don't know how to translate it into English. :D
--- Quote from: Valery Sedletski on November 27, 2017, 08:26:24 pm ---Expart? Do you mean, partfilt.flt/ext2flt.flt?
--- End quote ---
No, I was referring to this one:
http://service.software.ibm.com/os2dd/free/extpart/expartcp.exe
or non-LVM systems can use:
http://service.software.ibm.com/os2dd/free/extpart/expartw4.exe
which will also raise the kernel revison up to 14.091 (without SWC/PPA restricted features)
--- Quote ---The second one was created for ext2-os2.ifs. The 1st one was its enhanced version for fat32.ifs, to support additional partition types, by default. They could be added with "/p" switch too. hfsflt.flt is a filter from hfs.ifs (Macintosh HFS file system for OS/2). It has nothing to do with partition types. It is needed for Macintosh floppies.
--- End quote ---
You're right (HFSFLT.FLT). I have to look through my archives. But I think we used rewritable CDs in the end to transfer stuff to the Macintosh world for preprint processing or NetWare. Although back in 1997 Zip and Jaz drives were quite popular with the same trouble - PRM vs. Super Floppy.
--- Quote ---They have no BPB, which is required for OS/2. So, this filter creates a virtual BPB on the fly, which makes OS/2 happy with these floppies. Why only uniprocessor ACP1/ACP2?
--- End quote ---
Perhaps only at this point (2002) - I think it became fixed with later kernel, LVM and OS2DASD. It should be taken as a note that no original IBM installation media (WSEB, CP) included Extended Partition Support. The combination of later fixpaks and device driver updates made them play.
--- Quote ---partfilt.flt has some problems with SMP?
Or expart is something like partfilt.flt/ext2flt.flt, but for LVM systems? AFAIK, for LVM systems, such support is unneeded, because you can create the LVM info for any partition type, and the kernel will call all IFS'es for that partition, and it will be mounted if some IFS will recognize it. Or not all partition types are supported? 0x7/0xb/0xc supported, but Linux 0x83 is not? I am not sure. It is possible, indeed...
--- End quote ---
I don't want to be confusing. EXPART support for CP simply exchanges the following files:
--- Code: ---\os2\dll\ENGINE.DLL
\os2\dll\LVM.DLL
\os2\boot\OS2DASD.DMD
\os2\boot\OS2LVM.DMD
\os2\boot\IBM1S506.ADD
\os2\FORMAT.COM
\os2\LVM.EXE
\os2\LVMGUI.CMD
\os2\javaapps\LVMGUI.ZIP
\OS2DUMP
\OS2KRNL
--- End code ---
For an end-user or operator it's only interesting that OS2LVM device mapper relies on OS2DASD.
--- Quote ---If so, it is also possible to assign a 0x7 partition type to an ext2 partition. Linux does not care about partition types, so it would not hurt it. So, we can try testing it.
--- End quote ---
Sounds sane. Every IFS (ext2, hpfs, jfs) should also use the specified IFS partition id which is 7 (dual 0111). ;)
Valery Sedletski:
2Andreas Kohl:
> Actually I'm only 1/4 немецкий but 3/4 германский. I don't know how to translate it into English. :D
What's the difference between немецкий and германский? I found them synonymous :)
--- Quote ---I don't want to be confusing. EXPART support for CP simply exchanges the following files:
--- Code: ---\os2\dll\ENGINE.DLL
\os2\dll\LVM.DLL
\os2\boot\OS2DASD.DMD
\os2\boot\OS2LVM.DMD
\os2\boot\IBM1S506.ADD
\os2\FORMAT.COM
\os2\LVM.EXE
\os2\LVMGUI.CMD
\os2\javaapps\LVMGUI.ZIP
\OS2DUMP
\OS2KRNL
--- End code ---
--- End quote ---
Moveton from #os2russian said that his copy of EXPART package has os2krnl.smp file too. So, no SMP restriction, indeed. His package is, probably, is newer than yours.
> For an end-user or operator it's only interesting that OS2LVM device mapper relies on OS2DASD.
Of course. OS2DASD.DMD/OS2LVM.DMD pair from Aurora-level systems are used together. They could be exchanged to danidasd.dmd or os2dasd.dmd from Merlin, and everything will work. OS2DASD.DMD from Merlin and DANIDASD.DMD are 16-bit drivers. OS2DASD.DMD/OS2LVM.DMD from Aurora are 32-bit ones.
--- Quote ---
--- Quote --- If so, it is also possible to assign a 0x7 partition type to an ext2 partition. Linux does not care about partition types, so it would not hurt it. So, we can try testing it.
--- End quote ---
Sounds sane. Every IFS (ext2, hpfs, jfs) should also use the specified IFS partition id which is 7 (dual 0111). ;)
--- End quote ---
Ok, I tried to create an ext2fs partition with type 0x7. Without ext2fs partitions, mwdd32.sys/ext2-os2.ifs/ext2_lw.exe are loaded syccessfully and everything boots fine. With an ext2fs partition created, it hangs on pmshell.exe start (or on cntrl.exe start). It looks that it hangs on an attempt to mount a partition (all partitions, except for the OS/2 boot partition, are mounted about this point). So, it tries to mount it, but hangs, for some reason. This needs further investigation.
Andreas Kohl:
--- Quote from: Valery Sedletski on November 28, 2017, 09:44:14 am ---What's the difference between немецкий and германский? I found them synonymous :)
--- End quote ---
It could become more complicated than with русский/росси́йский which censored dictionaries handle synonymously. Не в бровь, а в глаз.
--- Quote ---Moveton from #os2russian said that his copy of EXPART package has os2krnl.smp file too. So, no SMP restriction, indeed. His package is, probably, is newer than yours.
--- End quote ---
Even the file expartcp.exe from the link I posted earlier includes this newer revision and removes the restriction. The changes were: OS2KRNL 14.092_SMP/UNI, additional OS2DUMP for SMP and a presence detection tool called ISSMP that's used by modified batch files. It's crucial parts should have been integrated into later fixpaks (XR_C003), so there's no need for the expartcp package anymore nowadays. But it simply visualises the difference between LVM and non-LVM environment.
--- Quote ---Of course. OS2DASD.DMD/OS2LVM.DMD pair from Aurora-level systems are used together. They could be exchanged to danidasd.dmd or os2dasd.dmd from Merlin, and everything will work.
--- End quote ---
As long no real LVM features were used. A LVM-based partition scheme that only contains compatibility volumes can be migrated this way.
--- Quote ---OS2DASD.DMD from Merlin and DANIDASD.DMD are 16-bit drivers. OS2DASD.DMD/OS2LVM.DMD from Aurora are 32-bit ones.
--- End quote ---
It should not be too complicated to distinguish between 10.xx and 14.xx (for 32-bit) revisions.
--- Quote ---Ok, I tried to create an ext2fs partition with type 0x7. Without ext2fs partitions, mwdd32.sys/ext2-os2.ifs/ext2_lw.exe are loaded syccessfully and everything boots fine. With an ext2fs partition created, it hangs on pmshell.exe start (or on cntrl.exe start). It looks that it hangs on an attempt to mount a partition (all partitions, except for the OS/2 boot partition, are mounted about this point). So, it tries to mount it, but hangs, for some reason. This needs further investigation.
--- End quote ---
Do we talk about a non-LVM system regarding this experiment? I would recommend a simple case with OS/2 on a primary FAT and second primary IFS partition (type 7) which holds ext2. CONFIG.SYS should be modified to remove all other IFS FSD and to keep only the ext2 stuff. Booting to command prompt (single OS/2 session) works? Next step could be the creation of an extended partition that containes a logical IFS partition with ext2. It's a good idea to make now a complete dump of the whole DASD before fancy things happen with VCU or different Linux installation procedures. Alternatively several small (virtual) DASD can be helpful for further investigations. For similar procedures VirtualBox SCSI support (BusLogic emulation) is a time saver.
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