Tape Backup

Paul Rubin wrote:

"Rob Turk" writes:
I don't know about customer administration but the other examples
sound like such small amounts of data that you might just encrypt
them and upload them to your ISP.

I've looked into that too, one of the major stumbling blocks has been how
to get the data out if something happens to the service provider. If you
get into a dispute, they can take your data hostage. If they go belly-up
or get if they get taken over, how do you ensure you can still get your
data back.

We were talking about stuff like drafts of a novel, which is just a
few MB. It's simple enough to put it in several places. I've also
had ISP's go belly-up several times; some scrambling resulted each
time but there was never a serious problem getting the data out. (In
one case we hired one of the belly-up ISP's suddenly-out-of-work
employees and they let him continue having access to the data center
so he could get our stuff out).

Even when you want to transfer to an ISP for better rates, how do you get
your backups out?

Download it, just like you uploaded it.

Again, for your personal MP3 collection there's no
problem. Besides, your MP3 collection is stored onto the Internet
multiple times over already.. ;^)

Heh, yes, an MP3 collection would be too large for this approach though.

If it's data that you depend your business or finances on I'd rather have
full control.

There's no such thing as full control, as the recent earthquake and
tsunamis in Asia recently illustrated for those of us who forget that
sometimes.

Anyone who thinks that there is "full control" should visit a museum which
has a full scale T-rex skeleton on display and consider what happened to
them.

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

Al Dykes wrote:

In article ,
Maxim S. Shatskih wrote:
Oh good point, I'm used to regular ATA. Hmm. I wonder if they will
start putting SATA in laptops, with an external SATA connector.

For now, there is 1394 instead (BTW - 1394 was once positioned instead of
SATA).
The 1394-to-ATA external box is not this expensive.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation

http://www.storagecraft.com




There is a PCMCIA SATA adapter. It's possible I read it in a review in
Tom'shardware in a review of SATA external exclosures.

Actually there are several available. Newegg carries three, and froogle has
70 hits including at least one brand that newegg doesn't carry.

I have a Buslink, which is basically just a Silicon Image chip on a board in
a case and seems to run on the Silicon Image reference drivers. So far it
works fine.

They're quite remarkably cheap.

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

On 14 Jan 2005 10:37:31 -0800, Paul Rubin
wrote:

Neil Maxwell writes:
CDR and DVDR are more reliable if verified, as you stated, but the
long-term life of them is unpredictable. If you're only counting on
them for 3 month lifetimes, you're probably OK, but if you want them
to last for a few years or more, you're playing with fire.

High quality CDR (e.g. Mitsui Archive Gold) have undergone a lot of
testing and seem to be quite stable for long periods. The jury is
still out for DVDR. Hard drives contain all kinds of seals, filters,
lubricants on mechanical parts, and flash memory parameters and
firmware dependent on floating charges, all of which can decay over a
period of years. Hard drives are quite unreliable for long term
storage.

Sorry, I've got a bunch of Mitsui and Kodak Gold and Silver from a few
years back that are nearly dead. I can't read them on most of my
readers and burners (multiple Plextors, NECs, Teacs, no-names), but my
Lite-on LTD163 will pull data that other drives give up on.

The only reliably readable disks I have from the past 6-7 years are
TY, and I've only been using them extensively for a couple of years,
so the data's not solid on them yet.

YMMV, as always.


--
Neil Maxwell - I don't speak for my employer

"J. Clarke" writes:
If a compressed, encrypted image is corrupted at all, it's probably
unrecoverable.

But will a virus typically attack any file that is not executable? While
some do, is that the normal action?

The virus might simply try to reformat a hard disk, or scribble on it
at random places. With an uncompressed disk there's some chance of
recovery; with compressed, encrypted disk, it's more likely hopeless.

It's actually quite easily done. You pull the board off of your off-site
drive and put it on the dead drive, which generally involves about ten
minutes with a screwdriver.

That's the easy part. The hard part is getting your data back after
you do the board swap. All I can say is, the attempts I've personally
had any contact with have been both expensive and ultimately
unsuccessful. But that's not all that many.

Oh good point, I'm used to regular ATA. Hmm. I wonder if they will
start putting SATA in laptops, with an external SATA connector.

Easily done--SATA PCCard adapters go for about 20 bucks.

Then you have to go through the PC card interface which is slower than
a disk interface, if my experience with an Adaptec 1480 scsi adapter
is any indication.

Read what I wrote again. I didn't say "use RAID for backup". I said backup
_to_ the RAID. The step I assumed was obvious was to "then pull both
drives, replace them with the next day's backup set, take one home, leave
the other in the safe".

There is software that does this with tapes. You need two tape drives and
the last time I checked the price the software was a thousand dollar add-in
to a several thousand dollar enterprise backup package.

The equivalent with tape would be to just write two backups, or even
write one backup to two tape drives. That doesn't sound like it needs
a multi-kilobuck software package.

There's a crossover point on very large systems where a tape library
becomes cost effective. For home use the cost of reliable tape is
prohibitive.

Well, if you really want to use two tape drives, that doubles the
cost, but you can get an LTO1 drive for about $600 now, so two of them
cost about what I paid for my home DDS2 drive in the mid 90's. I'd
say the cost is steep for a typical home user but I'd stop short of
"prohibitive".

Right now as mentioned, I'm using HD's for backup but I'm not
impressed with their reliability.

Are you using just one disk or are you using a set of them in a rotation
backup like you would with tapes?

I'm using them more like archival tapes, i.e. write-once, no rotation.

I have a number of tape drives. The trouble with them is that disk
capacity is increasing faster than tape capacity, and you need a
state of the art tape to back up a cheap disk.

That describes the situation really well. Right now, disk capacity
increase seems to have stalled, while tape is making some significant
advances, so for the first time in a while, high-end tape cartridges
hold more than a high-end disk drive's worth of data. I don't know if
that will last, and those tape systems really are too expensive for
home use (LTO3, SAIT).

And quite honestly, I'd trust disk over DDS. I've had DDS drives eat
multiple tapes.

I think a DDS backup might be more likely to fail at the moment that
it's made and there's always a chance of a drive eating a tape. I
haven't (yet) had bad experiences with tapes going south while sitting
on a shelf, which I've had with disk drives more than once.

On my infinite to-do list is to write some backup software that
uses a RAID-like strategy so if your backup needs, say, 5 tapes,
you can instead write it on (say) 8 tapes, and then if any three
of them get trashed you can still restore from the remaining 5.

Paul Rubin wrote:

"J. Clarke" writes:
If a compressed, encrypted image is corrupted at all, it's probably
unrecoverable.

But will a virus typically attack any file that is not executable? While
some do, is that the normal action?

The virus might simply try to reformat a hard disk, or scribble on it
at random places. With an uncompressed disk there's some chance of
recovery; with compressed, encrypted disk, it's more likely hopeless.

Compressed, encrypted file on a disk. Not a compressed, encrypted disk.

It's actually quite easily done. You pull the board off of your off-site
drive and put it on the dead drive, which generally involves about ten
minutes with a screwdriver.

That's the easy part. The hard part is getting your data back after
you do the board swap. All I can say is, the attempts I've personally
had any contact with have been both expensive and ultimately
unsuccessful. But that's not all that many.

Oh good point, I'm used to regular ATA. Hmm. I wonder if they will
start putting SATA in laptops, with an external SATA connector.

Easily done--SATA PCCard adapters go for about 20 bucks.

Then you have to go through the PC card interface which is slower than
a disk interface, if my experience with an Adaptec 1480 scsi adapter
is any indication.

Cardbus is 32 bit 33MHz, just like PCI. And even if it is slower than the
disk interface, no disk on the market can fill even a 100 MB/sec pipe.

Read what I wrote again. I didn't say "use RAID for backup". I said
backup
_to_ the RAID. The step I assumed was obvious was to "then pull both
drives, replace them with the next day's backup set, take one home, leave
the other in the safe".

There is software that does this with tapes. You need two tape drives
and the last time I checked the price the software was a thousand dollar
add-in to a several thousand dollar enterprise backup package.

The equivalent with tape would be to just write two backups, or even
write one backup to two tape drives. That doesn't sound like it needs
a multi-kilobuck software package.

If you write two backups then it takes twice as long and since tape is slow
anyway . . .

Now, actually backup to two tapes simultaneously and tell me how you did it
that didn't cost kilobucks.

There's a crossover point on very large systems where a tape library
becomes cost effective. For home use the cost of reliable tape is
prohibitive.

Well, if you really want to use two tape drives, that doubles the
cost, but you can get an LTO1 drive for about $600 now, so two of them
cost about what I paid for my home DDS2 drive in the mid 90's. I'd
say the cost is steep for a typical home user but I'd stop short of
"prohibitive".

Where can you get an LTO1 drive for $600 with any kind of reasonable
expectation that it's not busted or stolen?

And no, I don't want to use two tape drives, I want to have backup. I'm not
wedded to one technology like you seem to be. But you've pointed out that
if you do want to have redundant backup with tape you pay twice for the
drives or take twice as long for the backup.

Right now as mentioned, I'm using HD's for backup but I'm not
impressed with their reliability.

Are you using just one disk or are you using a set of them in a rotation
backup like you would with tapes?

I'm using them more like archival tapes, i.e. write-once, no rotation.

That's not backup, that's archiving.

I have a number of tape drives. The trouble with them is that disk
capacity is increasing faster than tape capacity, and you need a
state of the art tape to back up a cheap disk.

That describes the situation really well. Right now, disk capacity
increase seems to have stalled,

It has? 400 gig disks just started shipping for 400 bucks. Where can I get
a 400 gig tape for 400 bucks?

while tape is making some significant
advances, so for the first time in a while, high-end tape cartridges
hold more than a high-end disk drive's worth of data.

They may hold more than a "high-end disk drive" if by that you mean an
enterprise SCSI drive, but they don't hold more than a big consumer disk
drive.

I don't know if
that will last, and those tape systems really are too expensive for
home use (LTO3, SAIT).

And quite honestly, I'd trust disk over DDS. I've had DDS drives eat
multiple tapes.

I think a DDS backup might be more likely to fail at the moment that
it's made and there's always a chance of a drive eating a tape. I
haven't (yet) had bad experiences with tapes going south while sitting
on a shelf, which I've had with disk drives more than once.

On my infinite to-do list is to write some backup software that
uses a RAID-like strategy so if your backup needs, say, 5 tapes,
you can instead write it on (say) 8 tapes, and then if any three
of them get trashed you can still restore from the remaining 5.

That's commercially available from several vendors.

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

"J. Clarke" writes:
The virus might simply try to reformat a hard disk, or scribble on it
at random places. With an uncompressed disk there's some chance of
recovery; with compressed, encrypted disk, it's more likely hopeless.

Compressed, encrypted file on a disk. Not a compressed, encrypted disk.

OK, that too. Actually maybe even worse, depending on the type of
encryption and authentication. Change one bit and the whole file is
potentially turned into garbage.

Then you have to go through the PC card interface which is slower than
a disk interface, if my experience with an Adaptec 1480 scsi adapter
is any indication.

Cardbus is 32 bit 33MHz, just like PCI. And even if it is slower than the
disk interface, no disk on the market can fill even a 100 MB/sec pipe.

Yes, however, I've gotten crap performance through that Cardbus 1480
card. Maybe something else was wrong that I didn't try to pursue.
Have you actually measured performance of external discs through PC
card SATA?

If you write two backups then it takes twice as long and since tape is slow
anyway . . .

Eh? The problem with tape that I'm facing is that it's too fast, not
too slow. LTO1 has around 15MB native transfer speed which a PC disk
system -might- be able to keep up with. LTO2 is around 30MB/sec which
is hard to keep fed. LTO3 ($$$) is almost 70MB/sec. I just don't see
how to back up to LTO3 at full speed from any type of PC.
(Figures from http://www.span.com/catalog/index.php?cPath=21_45).

Now, actually backup to two tapes simultaneously and tell me how you
did it that didn't cost kilobucks.

I think the bottleneck would be hardware transfer speeds, not software.

Where can you get an LTO1 drive for $600 with any kind of reasonable
expectation that it's not busted or stolen?

There were several new units on ebay for around that price last week.
LTO1/LTO2 have gotten cheaper since LTO3 started shipping recently.

That describes the situation really well. Right now, disk capacity
increase seems to have stalled,

It has? 400 gig disks just started shipping for 400 bucks. Where can I get
a 400 gig tape for 400 bucks?

http://www.tape4backup.com/newlookltobrand.html
Scroll down to the LTO3 selection.

while tape is making some significant
advances, so for the first time in a while, high-end tape cartridges
hold more than a high-end disk drive's worth of data.

They may hold more than a "high-end disk drive" if by that you mean an
enterprise SCSI drive, but they don't hold more than a big consumer disk
drive.

LTO3 holds 400GB and SAIT-1 holds 500GB. SAIT-2 (scheduled for next
year) is supposed to hold 1000GB and there are no disk drives with
that capacity expected by then.

On my infinite to-do list is to write some backup software that
uses a RAID-like strategy so if your backup needs, say, 5 tapes,
you can instead write it on (say) 8 tapes, and then if any three
of them get trashed you can still restore from the remaining 5.

That's commercially available from several vendors.

I only use free software, but it's possible that there's some already
available.

Paul Rubin wrote:

"J. Clarke" writes:
The virus might simply try to reformat a hard disk, or scribble on it
at random places. With an uncompressed disk there's some chance of
recovery; with compressed, encrypted disk, it's more likely hopeless.

Compressed, encrypted file on a disk. Not a compressed, encrypted disk.

OK, that too. Actually maybe even worse, depending on the type of
encryption and authentication. Change one bit and the whole file is
potentially turned into garbage.

Then you have to go through the PC card interface which is slower than
a disk interface, if my experience with an Adaptec 1480 scsi adapter
is any indication.

Cardbus is 32 bit 33MHz, just like PCI. And even if it is slower than
the disk interface, no disk on the market can fill even a 100 MB/sec
pipe.

Yes, however, I've gotten crap performance through that Cardbus 1480
card. Maybe something else was wrong that I didn't try to pursue.
Have you actually measured performance of external discs through PC
card SATA?

Haven't measured, but was able to copy 35 gig in about a half an hour using
LiveState Recovery.

If you write two backups then it takes twice as long and since tape is
slow anyway . . .

Eh? The problem with tape that I'm facing is that it's too fast, not
too slow. LTO1 has around 15MB native transfer speed which a PC disk
system -might- be able to keep up with. LTO2 is around 30MB/sec which
is hard to keep fed. LTO3 ($$$) is almost 70MB/sec. I just don't see
how to back up to LTO3 at full speed from any type of PC.

RAID.

(Figures from http://www.span.com/catalog/index.php?cPath=21_45).

Believe it when you see it. The performance of _anything_ is inflated in
the advertising.

Now, actually backup to two tapes simultaneously and tell me how you
did it that didn't cost kilobucks.

I think the bottleneck would be hardware transfer speeds, not software.

Regardless of where the bottleneck is you need to have software which will
write the same data to two tapes simultaneously in order to backup to two
drives simultaneously.

Where can you get an LTO1 drive for $600 with any kind of reasonable
expectation that it's not busted or stolen?

There were several new units on ebay for around that price last week.

Is that the price they finally went for or the starting price? Lowest ebay
price I've seen is a bit less than the lowest Froogle price but that
auction still had some time to go. And they're still in the $800 range.

LTO1/LTO2 have gotten cheaper since LTO3 started shipping recently.

That describes the situation really well. Right now, disk capacity
increase seems to have stalled,

It has? 400 gig disks just started shipping for 400 bucks. Where can I
get a 400 gig tape for 400 bucks?

http://www.tape4backup.com/newlookltobrand.html
Scroll down to the LTO3 selection.

And what am I supposed to see there? I'm sorry, but a $130 cartridge and a
$5000 tape drive is not 400 gig for 400 bucks, it's 400 gig for 5130 bucks.

while tape is making some significant
advances, so for the first time in a while, high-end tape cartridges
hold more than a high-end disk drive's worth of data.

They may hold more than a "high-end disk drive" if by that you mean an
enterprise SCSI drive, but they don't hold more than a big consumer disk
drive.

LTO3 holds 400GB and SAIT-1 holds 500GB. SAIT-2 (scheduled for next
year) is supposed to hold 1000GB and there are no disk drives with
that capacity expected by then.

What's expected and what happens are two different things. Regardless,
that's a $6K drive and if the only vendor is Sony then I'd rather trust my
data to a shredder thank you.

On my infinite to-do list is to write some backup software that
uses a RAID-like strategy so if your backup needs, say, 5 tapes,
you can instead write it on (say) 8 tapes, and then if any three
of them get trashed you can still restore from the remaining 5.

That's commercially available from several vendors.

I only use free software, but it's possible that there's some already
available.

So far you have convinced me of nothing. Perhaps if you weren't buying
$6000 tape drives you could afford some software.

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

"J. Clarke" writes:
I think the bottleneck would be hardware transfer speeds, not software.

Regardless of where the bottleneck is you need to have software which will
write the same data to two tapes simultaneously in order to backup to two
drives simultaneously.

I just don't see any multi-kilobucks of software needed for that. I
could probably hack up GNU Tar to do it pretty straightforwardly.

There were several new units on ebay for around that price last week.

Is that the price they finally went for or the starting price? Lowest ebay
price I've seen is a bit less than the lowest Froogle price but that
auction still had some time to go. And they're still in the $800 range.

There were a few at $600 or so if you clicked "Buy It Now". Someone
may have snagged them all. I was surprised they were that low and
even $800 is pretty good. Just a few months ago I'd been seeing them
in the $1300 range but now you can get brand new Certance LTO2 drives
for $1700-ish from dealers.

And what am I supposed to see there? I'm sorry, but a $130 cartridge and a
$5000 tape drive is not 400 gig for 400 bucks, it's 400 gig for 5130 bucks.

We were discussing the media cost. Yes, the tape drive adds a lot.
LTO3 is way out of my price range for example. LTO2 is more than I
want to spend but not outside the realm of possibility if I can think
of a use for that much capacity. LTO1 even at $800 looks pretty
attractive, a much more serious medium than using a bunch of those
consumer hard drives.

I only use free software, but it's possible that there's some
already available.

So far you have convinced me of nothing. Perhaps if you weren't buying
$6000 tape drives you could afford some software.

There's absolutely no way I'm going to trust backups or security
(encryption) to software (or at least data layouts) that I don't have
source for and hasn't been publicly reviewed. I won't have my data
hostage to some software company. No amount of money in the world
(well...) could get me to run non-free software for stuff like this.

In article ,
Paul Rubin wrote:
"J. Clarke" writes:
I think the bottleneck would be hardware transfer speeds, not software.

Regardless of where the bottleneck is you need to have software which will
write the same data to two tapes simultaneously in order to backup to two
drives simultaneously.

I just don't see any multi-kilobucks of software needed for that. I
could probably hack up GNU Tar to do it pretty straightforwardly.

There were several new units on ebay for around that price last week.

Is that the price they finally went for or the starting price? Lowest ebay
price I've seen is a bit less than the lowest Froogle price but that
auction still had some time to go. And they're still in the $800 range.

There were a few at $600 or so if you clicked "Buy It Now". Someone
may have snagged them all. I was surprised they were that low and
even $800 is pretty good. Just a few months ago I'd been seeing them
in the $1300 range but now you can get brand new Certance LTO2 drives
for $1700-ish from dealers.

And what am I supposed to see there? I'm sorry, but a $130 cartridge and a
$5000 tape drive is not 400 gig for 400 bucks, it's 400 gig for 5130 bucks.

We were discussing the media cost. Yes, the tape drive adds a lot.
LTO3 is way out of my price range for example. LTO2 is more than I
want to spend but not outside the realm of possibility if I can think
of a use for that much capacity. LTO1 even at $800 looks pretty
attractive, a much more serious medium than using a bunch of those
consumer hard drives.


I've bought a couple hundered LT IV carts on ebay, a few at a time and
saved the little company I worked for at least 50% of street price.
At some point I realized that the name brand tapes (mostly FUJI) had a
lifetime no-questions-asked replacement warranty. That made buying
tapes a no-brainer, since I could even buy a broken tape and
eventually get a new tape for it. I also had Veritas backup software
that reported tape soft error rates, so I could see weak tapes
and cycle them out of the heavy rotations.

I use ebauy to by tapes that are listed as being unopened,
without hesitation.

OT: I forget how much data teh OP backs up. I'd look at DLT IV tape
(35GB/70 compressed) would be cheaper for the OP. Lots of drives and
tapes on Ebay.

DLT is so heavily used in business that you'll be able to get tapes,
and drives for a years, and 50 years from now I bet there will be some
data conversion companies that will read your tape if you should need
it.

--

a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.

Paul Rubin wrote:

"J. Clarke" writes:
I think the bottleneck would be hardware transfer speeds, not software.

Regardless of where the bottleneck is you need to have software which
will write the same data to two tapes simultaneously in order to backup
to two drives simultaneously.

I just don't see any multi-kilobucks of software needed for that. I
could probably hack up GNU Tar to do it pretty straightforwardly.

Now use that to back up a Windows box.

There were several new units on ebay for around that price last week.

Is that the price they finally went for or the starting price? Lowest
ebay price I've seen is a bit less than the lowest Froogle price but that
auction still had some time to go. And they're still in the $800 range.

There were a few at $600 or so if you clicked "Buy It Now". Someone
may have snagged them all. I was surprised they were that low and
even $800 is pretty good. Just a few months ago I'd been seeing them
in the $1300 range but now you can get brand new Certance LTO2 drives
for $1700-ish from dealers.

And what am I supposed to see there? I'm sorry, but a $130 cartridge and
a $5000 tape drive is not 400 gig for 400 bucks, it's 400 gig for 5130
bucks.

We were discussing the media cost.

Perhaps you were discussing the media cost. I was discussion the cost of
obtaining a backup. The media does you no good at all without the drive.

Yes, the tape drive adds a lot.
LTO3 is way out of my price range for example. LTO2 is more than I
want to spend but not outside the realm of possibility if I can think
of a use for that much capacity. LTO1 even at $800 looks pretty
attractive, a much more serious medium than using a bunch of those
consumer hard drives.

It may be a more "serious" medium, but does it really confer any advantage
when used as a backup device? Not an archiving device, a _backup_ device?

I only use free software, but it's possible that there's some
already available.

So far you have convinced me of nothing. Perhaps if you weren't buying
$6000 tape drives you could afford some software.

There's absolutely no way I'm going to trust backups or security
(encryption) to software (or at least data layouts) that I don't have
source for and hasn't been publicly reviewed. I won't have my data
hostage to some software company. No amount of money in the world
(well...) could get me to run non-free software for stuff like this.

Suit yourself. Personally I've got better uses for 6 grand than backing up
my video collection.

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)