[ltp] DVD-RAM on T42p

[Tino Keitel]

On Thu, Dec 23, 2004 at 01:00:16 +0100, Thomas Breitner wrote:
> Hi there, 
> 
> does anybody have an idea about the usage of dvd-ram-media for
> superbay-slim?
> 
> i would like to use it as backup-media, but i'm not quite sure if i've
> done it right. and because it's about my backup, perhaps someone can
> confirm my strategy:
> 
> 1. make a filesystem on the dvd-ram: i've used udf via
>    mkudffs --media-type=dvd-ram /dev/hdc
> 
> 2. create a fstab-entry for it:
>    /dev/hdc        /mnt/dvdram     udf
> noatime,rw,user,noauto,gid=1000,uid=1000,umask=003,unhide,utf8
> 0       0
> 
> 3. mount it && write to it && umount it
> 
> i'm especially interessted in the filesystem-specification for the
> dvd-ram. is it correct to use udf? are there any cons or pros?

You can use any file system in theory. However, since DVD-RAM disks
have a very limited number of write cycles, the file system should take
care of that, like UDF. I use UDF too and make backups on DVD-RAM
disks.

But I have one problem: it's damn slow. When I test it with dd to the
raw disk, I get nearly 2 MB/s for writing, but with a file system I
only get 500 kb/s or less. If I listen close to the drive, I can hear
it constantly seek on the disk during writing. I think this is the
reason for the low write speed.

Does anybody else has this problem and knows how to fix it?

Btw, another advantage of DVD-RAM disks is the higher compatibility compared
with DVD+R. The latter won't work in my older DVD drives, but the
DVD-RAM disks will do.

Regards,
Tino