[comp.unix.ultrix] Can V1.2 file systems be mounted under 3.0

ELSEN@esat.kuleuven.ac.be (Marc Elsen) (08/30/89)

    I will soon be upgrading from Ultrix 1.2 to 3.1 and I was wondering
whether V1.2 file systems can still be mounted under Ultrix 3.1.
The V3.0 Release Notes mention something about  a change to the
Clean Byte value on p2-40.Further it is stated that fsck should be run
at least once to make pre 3.0 file systems compatible with Ultrix 3.0.

Will this solve my problem or should I just create them again using 'newfs'
and restore files from backup (tar or dump) ?

Thanks for any help,
-- 


  Marc Elsen (System Manager/Software Engineer)
  Katholieke Universiteit Leuven
  Dep. E.S.A.T.
  Kard. Mercierlaan 94
  3030 HEVERLEE
  Belgium
              tel. 32(0)16220931(ext. 1080)

               EMAIL : elsen@esat.kuleuven.ac.be

                       ...!kulcs!kulesat!elsen (UUCP)
                       elsen%kulesat.uucp@blekul60 (BITNET)
                       psi%02062166012::elsen  (PSI MAIL)

grr@cbmvax.UUCP (George Robbins) (09/01/89)

In article <1444@esat.kuleuven.ac.be> ELSEN@esat.kuleuven.ac.be (Marc Elsen) writes:
> 
>     I will soon be upgrading from Ultrix 1.2 to 3.1 and I was wondering
> whether V1.2 file systems can still be mounted under Ultrix 3.1.
> The V3.0 Release Notes mention something about  a change to the
> Clean Byte value on p2-40.Further it is stated that fsck should be run
> at least once to make pre 3.0 file systems compatible with Ultrix 3.0.

As far as I know, there have been no major changes in the filesystem structure
that prevent mounting a 1.2 filesystem under 2.x or 3.x.  Somewhere along the
line, DEC fixed the "short directory" bug/feature from 4.2 BSD and then added
a "clean" flag to the super block.

The clean flag is basically advisory - if there have been no changes to the
filesystem since it was mounted/unmouted, fsck -p can skip checking it and
mount doesn't complain when you try to mount it.  You can still mount an
old (1.2) or "dirty" filesystem by using the "-o force" option to mount.

Warning: 4.3 Tahoe and Ultrix filesystems are less compatible - not sure if
this reflects any difference in the actual structure or just incompatible
notions on some superblock and partition table issues.

> Will this solve my problem or should I just create them again using 'newfs'
> and restore files from backup (tar or dump) ?

Still not a bad idea...

-- 
George Robbins - now working for,	uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)

mjb@acd4.UUCP ( Mike Bryan ) (09/01/89)

In article <7802@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) writes:
>In article <1444@esat.kuleuven.ac.be> ELSEN@esat.kuleuven.ac.be (Marc Elsen) writes:
>> 
>>     I will soon be upgrading from Ultrix 1.2 to 3.1 and I was wondering
>> whether V1.2 file systems can still be mounted under Ultrix 3.1.
>> The V3.0 Release Notes mention something about  a change to the
>> Clean Byte value on p2-40.Further it is stated that fsck should be run
>> at least once to make pre 3.0 file systems compatible with Ultrix 3.0.
>
>The clean flag is basically advisory - if there have been no changes to the
>filesystem since it was mounted/unmouted, fsck -p can skip checking it and
>mount doesn't complain when you try to mount it.  You can still mount an
>old (1.2) or "dirty" filesystem by using the "-o force" option to mount.

You don't need to use the "-o force" option to mount.  Assuming you
have the 1.2 filesystems in /etc/fstab, an fsck will automatically be
run on that filesystem when the system is booted.  The fsck will
properly setup the "clean byte", and those filesystems will then be
3.0 filesystems.  No problem!
-- 
Mike Bryan, Applied Computing Devices, 100 N Campus Dr, Terre Haute IN 47802
Phone: 812/232-6051  FAX: 812/231-5280  Home: 812/232-0815
UUCP: uunet!acd4!mjb  ARPA: acd4!mjb@uunet.uu.net
"Did you make mankind after we made you?" --- XTC, "Dear God"

grr@cbmvax.UUCP (George Robbins) (09/02/89)

In article <1989Sep1.125332.9286@acd4.UUCP> mjb@acd4.UUCP ( Mike Bryan          ) writes:
> In article <7802@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) writes:
> >In article <1444@esat.kuleuven.ac.be> ELSEN@esat.kuleuven.ac.be (Marc Elsen) writes:
> >>     I will soon be upgrading from Ultrix 1.2 to 3.1 and I was wondering
> >> whether V1.2 file systems can still be mounted under Ultrix 3.1.
> >
> >The clean flag is basically advisory - if there have been no changes to the
> >filesystem since it was mounted/unmouted, fsck -p can skip checking it and
> >mount doesn't complain when you try to mount it.  You can still mount an
> >old (1.2) or "dirty" filesystem by using the "-o force" option to mount.
> 
> You don't need to use the "-o force" option to mount.  Assuming you
> have the 1.2 filesystems in /etc/fstab, an fsck will automatically be
> run on that filesystem when the system is booted.  The fsck will
> properly setup the "clean byte", and those filesystems will then be
> 3.0 filesystems.  No problem!

Of course, assuming it's a one time cutover.  If you're stepping gingerly,
you may not want to have 3.x fsck "improve" the filesystem right off and
if you're switching back and forth in a test mode, you'd have to fsck
the filesystem again every time 1.2 gets its claws into it...

-- 
George Robbins - now working for,	uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)