When I tried to mount a Blu-ray Disc formatted with Windows7 GUI,
An error message showed.

[root@localhost src]# mount -r -t udf /dev/cdrom /mnt
mount: /dev/sr0: can't read superblock

OS:CentOS7
Media:BD-R/BD-RE

The file system is UDF2.6(BD-R), 2.5(BD-RE).
They can be read with Windows7 and consumer BD-Recorder.

I'm not sure what is the point.
Could you please give me a crue to solve the issue?

I'd appreciate it if you could help me.

it's normal.
try opening the disk from your favorite media player (e.g. vlc) instead.

although i don't quite understand what you want to read from it if you only formatted it...

After much googling I could not find anything that indicates linux supports UDF 2.6. I don't have a clue either. I assume this is a data CD and not a movie. I have not burned a data CD in windows for awhile but assume the default is still UDF vs ISO9660?

https://en.wikipedia.org/wiki/Universal_Disk_Format

oh, my bad, didn't think this through. i stand corrected.

maybe op could provide us with some low-level info about the disk - maybe with "fdisk -l" or "dmesg"?

Mr. ondoho and Mr. michaelk

Thank you for the messages.

The discs contain data and a captured stream of a web cam.
It was formatted in "Live File Format" and burnt data with packet writing on Windows7.

What I want to do on CentOS7 are:
- read and copy data.
- replay the stream.

It must be mounted before to realize them but failed.

Followings are detail info of this issue.

----
BD-RE windows format(udf2.5)

*dmesg log of mount failure
[root@localhost sobal]# mount -r -t udf /dev/cdrom /mnt
mount: /dev/sr0: can't read superblock
[root@localhost sobal]#
[root@localhost sobal]#
[root@localhost sobal]# dmesg

[26592.436142] UDF-fs: error (device sr0): __udf_read_inode: (ino 4294967295) failed !bh
[26592.436147] UDF-fs: warning (device sr0): udf_find_metadata_inode_efe: metadata inode efe not found
[26592.436149] UDF-fs: error (device sr0): __udf_read_inode: (ino 4294967295) failed !bh
[26592.436150] UDF-fs: warning (device sr0): udf_find_metadata_inode_efe: metadata inode efe not found
[26592.436151] UDF-fs: error (device sr0): udf_load_metadata_files: Both metadata and mirror metadata inode efe can not found
[26592.436152] UDF-fs: error (device sr0): udf_load_partdesc: error loading MetaData partition map 1


*Media information
[root@localhost sobal]# dvd+rw-mediainfo /dev/cdrom
INQUIRY: [PIONEER ][BD-RW BDR-209 ][1.20]
GET [CURRENT] CONFIGURATION:
Mounted Media: 43h, BD-RE
Media ID: RITEK/BW1
Current Write Speed: 2.0x4495=8990KB/s
Write Speed #0: 2.0x4495=8990KB/s
Speed Descriptor#0: 00/11826175 R@2.0x4495=8990KB/s W@2.0x4495=8990KB/s
READ DISC INFORMATION:
Disc status: complete
Number of Sessions: 1
State of Last Session: complete
Number of Tracks: 1
READ FORMAT CAPACITIES:
formatted: 11826176*2048=24220008448
00h(3000): 11826176*2048=24220008448
30h(3000): 11826176*2048=24220008448
30h(5000): 11564032*2048=23683137536
30h(1000): 12088320*2048=24756879360
31h(800): 12219392*2048=25025314816
READ TRACK INFORMATION[#1]:
Track State: complete
Track Start Address: 0*2KB
Free Blocks: 0*2KB
Track Size: 11826176*2KB
FABRICATED TOC:
Track#1 : 14@0
Track#AA : 14@11826176
Multi-session Info: #1@0
READ CAPACITY: 11826176*2048=24220008448
[root@localhost sobal]#

----
BD-R windows format(udf2.6)

*dmesg log of mount failure
[root@localhost sobal]# mount -r -t udf /dev/cdrom /mnt
mount: /dev/sr0: can't read superblock
[root@localhost sobal]#
[root@localhost sobal]#
[root@localhost sobal]# dmesg

[25895.151483] UDF-fs: error (device sr0): __udf_read_inode: (ino 4294967295) failed !bh
[25895.151488] UDF-fs: warning (device sr0): udf_find_metadata_inode_efe: metadata inode efe not found
[25895.151490] UDF-fs: error (device sr0): __udf_read_inode: (ino 4294967295) failed !bh
[25895.151491] UDF-fs: warning (device sr0): udf_find_metadata_inode_efe: metadata inode efe not found
[25895.151492] UDF-fs: error (device sr0): udf_load_metadata_files: Both metadata and mirror metadata inode efe can not found
[25895.151493] UDF-fs: error (device sr0): udf_load_partdesc: error loading MetaData partition map 1


*Media information
[root@localhost sobal]#
[root@localhost sobal]# dvd+rw-mediainfo /dev/cdrom
INQUIRY: [PIONEER ][BD-RW BDR-209 ][1.20]
GET [CURRENT] CONFIGURATION:
Mounted Media: 41h, BD-R SRM+POW
Media ID: CMCMAG/BA5
Current Write Speed: 12.0x4495=53940KB/s
Write Speed #0: 12.0x4495=53940KB/s
Write Speed #1: 10.0x4495=44950KB/s
Write Speed #2: 8.0x4495=35960KB/s
Write Speed #3: 6.0x4495=26970KB/s
Write Speed #4: 4.0x4495=17980KB/s
Write Speed #5: 2.0x4495=8990KB/s
Speed Descriptor#0: 00/11826175 R@12.0x4495=53940KB/s W@12.0x4495=53940KB/s
Speed Descriptor#1: 00/11826175 R@10.0x4495=44950KB/s W@10.0x4495=44950KB/s
Speed Descriptor#2: 00/11826175 R@8.0x4495=35960KB/s W@8.0x4495=35960KB/s
Speed Descriptor#3: 00/11826175 R@6.0x4495=26970KB/s W@6.0x4495=26970KB/s
Speed Descriptor#4: 00/11826175 R@4.0x4495=17980KB/s W@4.0x4495=17980KB/s
Speed Descriptor#5: 00/11826175 R@2.0x4495=8990KB/s W@2.0x4495=8990KB/s
POW RESOURCES INFORMATION:
Remaining Replacements:16843808
Remaining Map Entries: 0
Remaining Updates: 0
READ DISC INFORMATION:
Disc status: appendable
Number of Sessions: 1
State of Last Session: incomplete
"Next" Track: 1
Number of Tracks: 4
READ TRACK INFORMATION[#1]:
Track State: partial incremental
Track Start Address: 0*2KB
Next Writable Address: 736*2KB
Free Blocks: 24864*2KB
Track Size: 25600*2KB
READ TRACK INFORMATION[#2]:
Track State: partial incremental
Track Start Address: 25600*2KB
Next Writable Address: 26528*2KB
Free Blocks: 523360*2KB
Track Size: 524288*2KB
READ TRACK INFORMATION[#3]:
Track State: partial incremental
Track Start Address: 549888*2KB
Next Writable Address: 596192*2KB
Free Blocks: 11229696*2KB
Track Size: 11276000*2KB
READ TRACK INFORMATION[#4]:
Track State: partial incremental
Track Start Address: 11825888*2KB
Free Blocks: 0*2KB
Track Size: 288*2KB
FABRICATED TOC:
Track#1 : 14@0
Track#AA : 14@11826176
Multi-session Info: #1@0
READ CAPACITY: 11826176*2048=24220008448
[root@localhost sobal]#

----

I'm sorry I could not run fdisk without mounting.
Could you please let me know what information helps us.

Keisuke

According to this Wikipedia article, Windows Live File System is not compatible with versions of Windows earlier than Vista or with many other operating systems. (Typical Microsoft I must say.)

This other Wikipedia article has a chart which gives little cause for optimism.

Dear Mr.frankbell,

Thank you for the informations.

According to them, It seems impossible to mount UDF2.6 BD-R disc.

So, I tried to format discs with "InstantBurn5(CyberLink)" on Windows7 instead.
Then, they are mounted on CentOS7 successfully but the data are unable to read.


Now I met another trouble.

Followings are what I've done.

<BD-R/BD-RE formatted with InstantBurn5>
<mounting>
[root@localhost sobal]# mount -r -t udf /dev/cdrom /mnt => OK

<dmesg>
[18172.935670] UDF-fs: INFO Mounting volume 'InstantBurn', timestamp 2015/07/31 09:08 (121c)
[18172.936751] SELinux: initialized (dev sr0, type udf), uses genfs_contexts

<access confirmation>
[root@localhost sobal]# LANG=C ll /mnt
ls: cannot access /mnt/DVD_RTAV: Permission denied

[root@localhost sobal]# LANG=C ll /
drw-rw-rw-. 3 nfsnobody nfsnobody 232 7 31 08:29 mnt


There are no differences between BD-R(UDF2.6) and BD-RE(UDF2.5),
I have no idea why BD-R/BD-RE are unable to access even though mounted successfully.
Is it the matter of permission?

For example,

<DVD-RW formatted with Windows7>
<mounting>
[root@localhost sobal]# mount -r -t udf /dev/cdrom /mnt => OK

<dmesg>
[ 1008.894613] UDF-fs: INFO Mounting volume 'UDF Volume', timestamp 2015/07/22 14:44 (121c)
[ 1008.991251] SELinux: initialized (dev sr0, type udf), uses genfs_contexts

<access confirmation>
[root@localhost /]# LANG=C ll /mnt
total 0
drwxrwxrwx. 2 nfsnobody nfsnobody 196 Jul 22 14:51 DVD_RTAV

[root@localhost /]# LANG=C ll /
drwxrwxrwx. 3 nfsnobody nfsnobody 200 Jul 22 14:51 mnt

DVD-RW has no problem. It's perfectly healthy.

I'm wondering if someone could help me.

Keisuke

you have to search the web for how linux supports this file system (udf?), esp. on blueray.
tbh, i have no clue, but generally speaking centos is not the best os for media stuff.

maybe it works on linux mint or ubuntu? in that case it maybe that centos uses older libraries, hence the errors.

can't you just burn the data using fat32 filesystem?
i don't know, maybe that's stupid advice, i never burn cds/dvds...

ps:
some of the above commands require sudo, e.g. "sudo fdisk -l".

Thanks for all responders,

I have found a solution at last!

What I wanted to do are below:
-Write realtime captured stream into BD-R/RE on Windows7.
-Read it to copy data and replay stream on CentOS7.

And the solution is:
-Format BD-R/RE with Nero InCD on Windows7.
->The filesystems are UDF2.6(BD-R), UDF2.5(BD-RE).
-Those formatted BD discs can be mounted and read on Windows7, BD recorder/player, and CentOS7.

I'm not sure how different those formats between with Windows7 GUI, InstantBurn5 and Nero InCD,
but their behaviors are completely different.

formatter UDF Ver.(BD-R/RE) mount on CentOS read on CentOS
-----------------------------------------------------------------------
Windows7 GUI 2.6/2.5 no no
InstantBurn5 2.6/2.5 yes no
Nero InCD 2.6/2.5 yes yes

"Nero InCD" is the savior for me!

Keisuke