.linux.setup:7783 comp.os.os2.setup.storage:380   
   From: "Alex Taylor"    
      
   On Mon, 14 Feb 2011 04:12:50 UTC, Jonathan de Boyne Pollard    
    wrote:   
      
   > > Maybe it is, but there is demonstrably an existing base of legacy    
   > > software that rigidly assumes it. (OS/2 has always been notoriously    
   > > strict about this, or at any rate since the Warp 3 days at least.)   
   >    
   > Actually no.  And that's the point.  There's an existing base of    
   > software.  (What was the point of the word "legacy" in that sentence?     
      
   Editing error.  Comes of trying to reword the sentence partway through   
   writing it. :)   
      
   > But it's software that *enforces* the restriction, rather than that    
   > *assumes* it.  IBM's FDISK, for example, enforces various restrictions,    
   > purportedly for the benefit of other operating systems.  But in fact    
   > those other operating systems do *not* assume the restrictions being    
   > enforced.  FDISK enforces cylinder alignment.  But I cannot recall off    
   > the top of my head *any* operating system back as far as DR-DOS 6 that    
   > actually *requires* this in order to work.   
   >    
   > FDISK has several wholly unnecessary impositions, and this is one.   
      
   Yup.  I ran up against this back in 1997 or so when I first tried to   
   install Linux and OS/2 (Warp 3, in that instance) along side each other.   
   I was eventually pointed to using the FDISK from OS/2 2.11, which was   
   quite happy to work with the Linux-created partition layout.     
      
   I guess my real point was that this problem isn't specific to LVM,   
   although it's possibly specific to OS/2 in general.   
      
      
   > It's what IBM's LVM is doing that isn't fine.  It's making unwarranted    
   > assumptions about where it can just grab an unallocated disc block    
   > without explicitly allocating it.  As I noted, other disc management    
   > systems *do not do things this way*.  Microsoft's Logical Disk Manager    
   > uses a special partition, whose type is "LDM Metadata" (EFI partition    
   > type 5808c8aa-7e8f-42e0-85d2-e1e90434cfb3), and puts the metadata    
   > there.  The Linux LVM (we are told) stores the metadata within each    
   > partition.  There's a reason that the rest of the world doesn't do    
   > things the IBM LVM way, and hasn't done for at least a decade now (There    
   > is Windows 2000 Server doco that talks about the pitfalls of expecting    
   > unallocated areas of the partition table to be usable.), and this    
   > experience *is* that reason.  It's a flawed and selfish design and    
   > doesn't work.   
      
   Begs the question of course... what, if anything, can be done about it?   
      
   I suppose some ambitious developer could rewrite LVM, although when IBM   
   open-sourced it for the Linux people to use, they only seem to have   
   released half of it: LVM.DLL was open-sourced, but not (AFAIK) OS2DASD.DMD   
   and OS2LVM.DMD, which AIUI do fairly critical parts of the work...   
      
   --    
   Alex Taylor   
   Fukushima, Japan   
   http://www.socis.ca/~ataylo00   
      
   Please take off hat when replying.   
      
   --- Internet Rex 2.31   
    * Origin: Newscene Usenet News Service, http://www.newscene.co (1:261/20.999)