USB DVD/CD RW slow and odd?

[lugoteehalt]

USB read/write dvd/cd drive. Tend to use it for packet writing with a udf file system on a dvd+rw.

Initially it records quickly but then slows right down with long pauses; occasionally get the same thing with flash drive - is this natural or some problem with caching or whatever?

A similar thing: it does not like complex directory trees, such as might be got from unpacking a large tar archive. It gives long pauses, misses out directories, produces corrupt files and directories (they are coloured red in mc with a question mark). Then it tends to unset itself and sort of go mad, spin very fast, and produce a smell of burning. Is this dislike of complex directory trees natural? Unmounting often produces the remark that the thing is 'dirty', mount's quotes.

Thanks any help.

[saikee]

I think there is a speed for CD-rewriters, a speed for the medium and also a speed for the controller. Say if the CD/DVD rewriter is capable of 8x speed but an old disc 2x is used then everything has to be slowed down to suit the lower speed component.

Apart from the above dvd-rw also need re-formatted, an operation that can take some time, just to be able to write on an old disc.

The burning smell may be associated with intensive operation of the device.

Losing data information in the transfer is more difficult to assess but it is possible the transfer program may be having a difficulty with or simply does not support long file names or foreign characters.

There is also a possibility that the data at the source point is in a corrupted state so that the hard disk need to be read several times and data obtained is still unreliable.

[lugoteehalt]

I think there is a speed for CD-rewriters, a speed for the medium and also a speed for the controller. Say if the CD/DVD rewriter is capable of 8x speed but an old disc 2x is used then everything has to be slowed down to suit the lower speed component.

There is also a possibility that the data at the source point is in a corrupted state so that the hard disk need to be read several times and data obtained is still unreliable.Thanks.

Yes, max speed of DVD+RW drive is x8 (and vaugh impression it defaults to this) and for disk itself is x4. Don't know how to fix this since packet writing just uses cp etc. in normal way. Changed environment variable for writing speed to =0, also wodim dev=/dev/sr0 -load speed=0, although wodim isn't used.

There may have been some improvement, in that it runs at constant speed and not fast at start then long pauses. But corrupted silly files and directories, but not always.

It's from dvd -> same dvd, unzipping large file.

Disk a bit scratched perhaps that's it.

[lugoteehalt]

Keeps doing this sort of thing to me:

lugo@debian:~$ umount pkt
cdrom: sr0: dirty DVD+RW media, "finalizing"

lugo@debian:~$ ls -l /media/dvd0
sr 1:0:0:0: SCSI error: return code = 0x08000002
sr0: Current: sense key: Hardware Error
Additional sense: Timeout on logical unit
end_request: I/O error, dev sr0, sector 197936
udf: udf_read_inode(ino 49484) failed !bh
total 0
drwxr-xr-x 3 lugo lugo 84 2007-10-02 23:55 jdk1.6.0_02
drwxr-xr-x 2 root root 40 2007-10-02 17:12 lost+found
?--------- ? ? ? ? ? /media/dvd0/tutorial.zip

<umount packet thing.>

lugo@debian:~$ mount pkt
UDF-fs INFO UDF 0.9.8.1 (2004/29/09) Mounting volume 'LinuxUDF', timestamp 2007/10/02 17:12 (103c)
lugo@debian:~$ ls -l /media/dvd0
total 33238
drwxr-xr-x 3 lugo lugo 84 2007-10-02 23:55 jdk1.6.0_02
drwxr-xr-x 2 root root 40 2007-10-02 17:12 lost+found
-rw------- 1 lugo lugo 34035084 2007-09-21 21:27 tutorial.zip

lugo@debian:~$ ls -l /media/dvd0/jdk1.6.0_02/demo/
udf: udf_read_inode(ino 28785) failed !bh
udf: udf_read_inode(ino 29025) failed !bh
udf: udf_read_inode(ino 29110) failed !bh
udf: udf_read_inode(ino 32437) failed !bh
udf: udf_read_inode(ino 32501) failed !bh
udf: udf_read_inode(ino 33306) failed !bh
total 0
drwxr-xr-x 12 lugo lugo 532 2007-06-15 02:02 jvmti
?--------- ? ? ? ? ? /media/dvd0/jdk1.6.0_02/demo/applets
?--------- ? ? ? ? ? /media/dvd0/jdk1.6.0_02/demo/jfc
?--------- ? ? ? ? ? /media/dvd0/jdk1.6.0_02/demo/management
?--------- ? ? ? ? ? /media/dvd0/jdk1.6.0_02/demo/nbproject
?--------- ? ? ? ? ? /media/dvd0/jdk1.6.0_02/demo/plugin?--------- ? ? ? ? ? /media/dvd0/jdk1.6.0_02/demo/scripting