Re: [gentoo-user] new machine : DVD drive

[Andrea Conti]

>> (1) do I need to configure the kernel to find the drive ?

It's basically handled exactly the same as a CD drive, so you need the
same configuration options you would use for that.

> Yes.  As a minimum have a look at BLK_DEV_SR and BLK_DEV_SR_VENDOR.  You may
> also need SCSI_PROC_FS for legacy applications.  The AHCI drivers would
> probably be enabled for your hard drive SATA controller anyway.

BLK_DEV_SR_VENDOR made sense when every drive manufacturer adopted their
own "standard" in designing interface protocols... with every drive made
on the planet in the last ten years being mmc-compliant, there is not
much point in still using that. Not that it hurts even if it's not needed...

>> (3) are there rewritable DVDs, as there used to be rewritable CDs ?
>> -- among the specs are much slower speeds labelled 'RW'.
>
> Yes, +RW, -RW, but don't know much more on this other than older DVD writers
> would only do one format not another and if you didn't pay attention to the
> specification/limitations of your hardware you could end up buying the wrong
> type of DVDs.  Someone more experienced on recording media could answer this
> better.

Every modern recorder does both standards; depending on both the burner
and the reader you might find that one standard works better than the
other (i.e. has lower read error rates). Trial and error seems to be the
only working approach...

As for the standards, if you're just burning backups they're basically
equivalent. The +RW standard is theoretically more flexible as media can
be formatted in a "packet" mode which allows (almost) random r/w access,
but in my experience software support and reliability have always been
lousy, so forget about it.

+RW media cannot be erased in the same way CD-RWs are erased, -- you can
only overwrite it with new data. -RW behaves the same as CD-RWs in this
regard.

If you need rewritable DVD media with reliable random r/w access (but
this doesn't seem to be your case), there is a third standard (DVD-RAM)
which uses special disks with hardware sector marks. Drive support is
not hard to find nowadays (the drive you cited actually supports it),
but writing is slow, good media is expensive and the disks cannot be
read in most "normal" dvd drives; I have no idea about the state of
software support in Linux.

>> (4) anything else I sb aware of ?

DVDs (especially rewritable ones) are much less resilient than CDs.
Don't rely on a recorded DVD to be still readable after more than 3-4
years, because it probably won't be. While good quality (i.e. expensive)
brand media tends to be a little more durable, DVDs are not the right
choice for long-term archival.

> Given your adoption rate of new technology I suggest you consider buying a
> BluRay player if not recorder, because I don't know how long it will be before
> DVDs become obsolete too.

I doubt BD-R will ever supplant DVD-R the same way DVD-R did with CD-R.

When DVD-R came out there were no practical and affordable alternatives
for recording and transporting large quantities of data. Nowadays, on
the other hand, flash storage is ubiquitous and cheap enough to satisfy
the needs of most people. This slowed the adoption of BD-R a lot, to the
point that I'm not sure it will ever become a widespread technology.

IOW, I would only consider shelling out the cash for a BD-R drive if it
made sense for my current storage needs, not as an investment for the
future.

my € 0.02,
andrea