[osol-discuss] snv_70 odd behavior

Dennis ,  I agree   with you  that  SNV70   is not  mounting  a Vista UDFS  dvd  correctly

I did a clean Install of Snv_70  on a new disc ( a 10.000 rpm  disc which  contributes
nicely to the speed  of the system btw )

The automount  by HAL  and rmmount did not mount the UDF  filesystem

All it did was mounting a HSFS  where  a little text file " readme.txt"  with
the following message appeared.

"This disc contains a "UDF" file system and requires an operating system

that supports the ISO-13346 "UDF" file system specification."



Only after  I did the below  command  could I see the files on the UDF  disc.

# mount -F udfs -o ro /dev/dsk/c1t0d0s2 /mnt

and even then  fstyp(1M)   reports that its a HSFS   file system

# fstyp -v  /dev/dsk/c1t0d0s2 | more
hsfs
CD-ROM is in ISO 9660 format
System id:
Volume id: LRMCXFRE_EN_DVD
Volume set id: LRMCXFRE_EN_DVD
Publisher id: MICROSOFT CORPORATION
Data preparer id: MICROSOFT CORPORATION, ONE MICROSOFT WAY, REDMOND WA 98052, (425) 882-8080
Application id: CDIMAGE 2.52 (03/09/2004 TM)
Copyright File id:
Abstract File id:
Bibliographic File id:
Volume set size is 1
Volume set sequence number is 1
Logical block size is 2048
Volume size is 1853755
-------
Media format  detection is obviously  not working   with UDF.


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Some DVDs contain two filesystems [1], hence mountable as either hsfs
and udfs. fstyp returns the first match, and that's what HAL will use.
One fix would be to treat these in the same fashion we treat hybrid
data+audio media, i.e. pop a dialog asking for user's preference. A
simpler but less generic fix would be in HAL: if libfstyp returns hsfs,
call it again to check for udfs [2]. If anyone is willing to contribute
code [3], I'll happily sponsor.

-Artem

[1] http://en.wikipedia.org/wiki/Universal_Disk_Format#Media
[2] http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/cmd/hal/probing/volume/probe-volume.c#635
[3] http://opensolaris.org/os/communities/participation/

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If your problem is that the medium you mounted is incosistent, then you would
complain at the manufacturer/publisher.

The problem with CD/DVD/.... media is that this media usually now contain 3
filesystems in 4 flavors:

-    ISO-9660
-    ISO-9660 Rock Ridge extensions

-    Joliet

-    UDF

If you ask a utility (like e.g. fstyp) whether a specific filesystem type is
available, you will typically get positive replies for all filesystems!

Media handling on Solaris is unfortunately based on asking this way and the
first ask that results in a positive will be turned into a mount action.

**** I just found that we did forget to enhance /usr/lib/fs/hsfs/fstyp to know
about Joliet when Joliet support was added a year ago....

In any case, we will get into trouble!

-    The DVD manufacturers believe that there is a standard that requires
    UDF on a DVD medium.

-    There is no such "requirement" for other media types....

-    Many people believe that UDF is a better choice than ISO-9660, but this
    is not correct from my experiences:

-    UDF limits single files to a max of ~ 200 GB

-    ISO-9660 limits single files to 8 TB

This all will not create real problems in case that you manually mount the
medium, but it will cause trouble if you auto-mount with any possible rule-set.