[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, [phone]

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.