From: rhealey@rogue.digibd.com (Rob Healey)
Subject: Re: ufs boot partitions are certain death!
Organization: DigiBoard Incorporated, Eden Prairie, MN
Date: Sat, 23 Jan 1993 02:17:36 GMT

In article <1jm1btINN356@zikzak.apana.org.au>, zik@zikzak.apana.org.au (Michael Saleeba) writes:
|> rhealey@rogue.digibd.com (Rob Healey) writes:
|> 
|> >	AmigaUNIX does not like / and /usr being on seperate file systems
|> >	so keep / and /usr on the same filesystem. Preferably ufs.
|> 
|> Well I can't say I'd recommend ufs for a boot partition. I've been
|> messing with Amiga UNIX for around a year now and I've always had this
|> creeping problem with inodes just randomly being munged. As the system
|> has been getting busier (it's public access) the problem has been
|> getting worse. It would usually cause something like this on the
|> console:
|> 
	I should have qualified that as Preferably ufs on 2.1 systems. Using
	ufs on any version prior to 2.1 will probably cause corruption
	or panics due to the way ufs allocates/deallocated blocks of
	memory to do it's work. These allocation/deallocation routines were
	running at the wrong spl() level before 2.1 and thus corruption
	could occur. People blame it on ufs but it really wasn't ufs's
	fault, it just used the buffer deallocation/aloocation routines
	alot more vigorously than the rest of the OS.

	If you aren't running 2.1 than stick to s5 even though 14 character
	filename lenthis brain damage. B^(.

|> Filesystem            kbytes    used   avail capacity  Mounted on          
|> /dev/dsk/c6d0s1        24576   17772    6804    72%    /          (s5)
|> /dev/dsk/c6d0s4       245884  167406   53889    76%    /system    (ufs)  
|> /dev/dsk/c0d0s2       260628  235807   17002    93%    /news      (ufs)
|> /dev/dsk/c0d0s1          807       5     761     1%    /locks     (ufs)
|> /dev/dsk/c6d0s5        88750   26371   53504    33%    /home      (ufs)
|> 
|> So it boots off a _small_ s5 partition. Nearly everything that is
|> useful but not essential for booting is on /system, and there are big
|> fat gobs of soft links between the two filesystems. Quite early in the
|> startup /system is mounted and things become usable. You may wonder
|> why I went to all this trouble to have a s5 boot partition,
|> particularly when I can't stand the stupid 14 character filename
|> limit. The answer is simple - I haven't lost a single inode since I
|> changed over.
|> 
|> QED.
|> 
|> And now I can sleep soundly at night, knowing that my password file
|> and my /usr/bin will be there in the morning!
|> 
	But the rest of your partitions might be clobbered by buffer
	corruption so you aren't out of the woods yet. s5 is slow enough
	that it vastly reduces the likelyhood of buffer corruption. ufs's
	problem is that it is too damn fast in the buffer allocation/
	deallocation dept so there are more opportunitys for the
	buffer lists to be mangled.

|> The moral of the story - DON'T USE ufs BOOT PARTITIONS! THEY ARE POISON!
|> 
	Only if your OS < 2.1. Since you are from down under I assume
	2.03 is all you can get at. I would STRONGLY urge you to ditch
	ALL ufs partitions if you are running anything other than 2.1,
	it WILL bite you in the ass if you don't. It's only a matter
	of time...

	Under 2.1 I've paniced my system constantly testing new driver
	code and beated on it relentlessly and it only uses ufs. I
	have yet to lose any file on root and have only lost a very
	few "active at the time of panic" files on /home.

	ufs boot partitions are only poison on < 2.1, for 2.1 AmigaUNIX it is
	the only way to go.

		-Rob