scsi dvd writers & tape drive

[Dilbert Firestorm]

hey all

anyone know of other scsi dvd writers (RW or RAM)?

the ones I've found so far are from Pioneer & Panasonic.

I'm also looking at a scsi tape drive from sony SDT-11000. any comments
on this. any alternates to it?

which method is better for backing up data, DVD or tape?

is dvd faster than tape on backup?

 

[J. Clarke]

hey all

anyone know of other scsi dvd writers (RW or RAM)?

the ones I've found so far are from Pioneer & Panasonic.

I'm also looking at a scsi tape drive from sony SDT-11000. any comments
on this. any alternates to it?

which method is better for backing up data, DVD or tape?

is dvd faster than tape on backup?

If you are constrained to use SCSI for the DVD writer then it's not a very
attractive alternative. Neither Pioneer nor Panasonic lists any
current-production SCSI DVD writers--the ones that are available are old,
slow, and write a limited number of formats. You'd do much better to go
with one of the multiformat ATAPI DVD recorders IMO.

The tape drive you're looking at can under ideal conditions write 144 meg a
minute uncompressed--tape capacity and performance is usually quoted
compressed for some stupid reason--don't believe the numbers the
manufacturer quotes.

The fastest SCSI DVD recorder that Panasonic made did 83 on DVD-RAM media--I
don't have the data on the last SCSI Pioneer. Current generation ATAPI
drives using compatible media and software that fully supports the drive
can write 396 MB/min on DVD-RAM and over 1 GB/min on write-once media.

So which is faster depends on what generation of DVD and what media you're
using.

That's not the whole story though--DVD-RAM media doesn't come any larger
than 4.7 GB--while you can buy 9.4 gig disks they're double sided and you
have to flip them over--nowhere to write a label on them either unless you
put it right around the hub. A single 4mm DDS-4 tape holds 20 gig. So
that's four media changes on the DVD for every one on the tape. You can
also get dual-layer write-once DVD media, but max write speed on that is
only 190 MB/min. There's also a cost issue. DDS-4 tapes can be obtained
for about $5 per tape. Dual-layer DVDs go for about $10 each. 5X DVD-RAM
disks go for about $8. 4X DVD rewriteable disks go for about $2 each, 16X
write-once DVD goes for about 80 cents but it's write-once--for backup that
can get expensive quickly. (note--lurkers--those are ballpark prices--if
you can find them ten cents cheaper somewhere good for you)

So what we have is that DVD is going to cost more, it's going to be slower
if you use an old SCSI drive or faster if you use a new ATAPI drive, and
it's going to require 2-4 times as many media changes.

An alternative to consider is using hard disks as backup media--treat them
like tapes--if one fails, throw it away. That seems expensive, but it's
not really--you pay about $0.50/GB for 4X rewritable DVD, you pay about the
same for 200 gig hard disks.

 

[Peter]

An alternative to consider is using hard disks as backup media--treat them

like tapes--if one fails, throw it away. That seems expensive, but it's
not really--you pay about $0.50/GB for 4X rewritable DVD, you pay about the
same for 200 gig hard disks.

And don't forget: it will be 20-40 times less media changes!

 

[Mike Redrobe]

which method is better for backing up data, DVD or tape?

is dvd faster than tape on backup?

If you're doing lots of single file restores maybe
(Think of random access time of DVD vs tape ! )

DVDs or USB hard drives can also be used on any PC,
not just the only PC (server) you have with a tape drive.

Portable (usb) hard drives are taking over from tape backup
for some people, since tape capacities are lagging behind.

Do use multiple usb drives in rotation, not just one!
(and keep one offsite...)

Home users may use DVD for backup, but DVDs only
store 4gb per disk, and have little support in server backup
software.

Many people rarely TEST that their backup will actually
RESTORE especially when using tape, until its too late.

Whatever backup method you use, try restoring a random file
every few weeks, or even a full restore to a spare machine,
you may be surprised at the results.

 

[Jonathan Sachs]

DVDs or USB hard drives can also be used on any PC,
not just the only PC (server) you have with a tape drive.

Say rather that external devices can be used on any PC, not just the PC in
which the devices installed.

Having a DVD does no good if you have an internal DVD drive and the machine
to which you must restore does not.

Conversely, if you have an external tape drive, you can move it to another
machine easily. I use only external drives for this reason.

 

[J. Clarke]

Say rather that external devices can be used on any PC, not just the PC in
which the devices installed.

Having a DVD does no good if you have an internal DVD drive and the
machine to which you must restore does not.

Conversely, if you have an external tape drive, you can move it to another
machine easily. I use only external drives for this reason.

With DVD drives going for 25 bucks I don't see lack of one as an obstacle.

There's also the option of using an external DVD burner.

 

[Jonathan Sachs]

Jonathan Sachs wrote:

With DVD drives going for 25 bucks I don't see lack of one as an obstacle.

Then you must not work for typical American business, where old machines are
generally kept in service until they become impossible to maintain, and
do-it-yourself upgrades are frowned upon!

One may not safely make assumptions about where one will have to restore
after a crash, or to what type of machine. One may PLAN where, etc., or one
may prepare for the broadest practical range of possibilities.

There's also the option of using an external DVD burner.

True, that's another viable type of external device.

I'm not arguing for or against any particular type of device here; I'm just
pointing out a fact which many users are likely to overlook until it bites
them in the arse.

 

[J. Clarke]

Then you must not work for typical American business, where old machines
are generally kept in service until they become impossible to maintain,
and do-it-yourself upgrades are frowned upon!

One may not safely make assumptions about where one will have to restore
after a crash, or to what type of machine. One may PLAN where, etc., or
one may prepare for the broadest practical range of possibilities.

But with the tape drive you're making the assumption that there is a SCSI
host adapter in the target machine. If there isn't then you have you have
to add one just as you might have to add a DVD drive. And if you're
planning to pull the host adapter from the busted machine you can pull the
DVD drive from it just as easily. So from that viewpoint it would appear
to be a wash.

True, that's another viable type of external device.

I'm not arguing for or against any particular type of device here; I'm
just pointing out a fact which many users are likely to overlook until it
bites them in the arse.

In that case, the tape drive is more likely to bite them in the arse than is
the DVD drive. DVD drives are commodity items in stock at Wal-Mart and
most new machines come with them installed. DDS4 drives are harder to come
by. And any machine that can support a CD drive can support a DVD drive.
If the machine you're going to restore to doesn't have any free PCI slots
then there's no way to attach the tape drive.

If you're really going for worst-worst case you should have backups on two
different types of media.

 

[Andy Ball]

JC> But with the tape drive you're making the assumption

that there is a SCSI host adapter in the target
machine...If the machine you're going to restore to
doesn't have any free PCI slots then there's no way to
attach the tape drive.

USB?

- Andy Ball

 

[J. Clarke]

JC> But with the tape drive you're making the assumption

USB?

Only one USB tape drive on the market, a 50 gig 8mm Sony, also sold by
Lacie. There are some Travans but Travan doesn't count--it's
consumer-crap.

 

[Folkert Rienstra]

Only one USB tape drive on the market, a 50 gig 8mm Sony, also sold by
Lacie. There are some Travans but Travan doesn't count--it's consumer-crap.

I think he meant USB to SCSI, read USB2Xchange and similar.