Tape Backup

Paul Rubin wrote:

"J. Clarke" writes:
If you get hit by a virus while you backup drive is
attached, poof goes your backup.

And how is copying infected files to a tape superior to copying them to a
disk?

I think the idea is that you could have an uninfected backup drive
attached to your PC when the virus runs, the virus can wipe out the
backup drive even though you weren't doing a backup at the time.

The solution is if you're backing up to HD's, use removable HD's and
make sure they're actually removed except when a backup is in
progress.

The thing is, if the machine is "hit by a virus" while the daily backup disk
is in the machine you lose that day's data, not the previous day's.
Assuming that the virus will actually corrupt a compressed, encrypted image
file in a nonrecoverable way.

If your house gets hit by a lightning strike, poof goes your backup.

And there is something magic about tape that makes it immune to the
intense
magnetic fields that go with a lightning strike? How is it that a disk,
with its much higher coercivity and its metal shell all around the media
manages to get damaged while a tape survives?

The magnetic files aren't THAT strong. Neither the disk platters nor
the tape gets erased. The lightning fries the drive electronics (disk
or tape), not the media. With a disk, once the electronics are fried,
you can't read the platters any more, without some ultra-expensive
data recovery attempt that isn't successful all that often. With
tape, you just put the tape into another drive and read it normally.

If the contents of the platters remain undamaged then the recovery isn't
going to be all that expensive--a circuit board swap will probably do it.

You seem to be assuming that someone performing disk-based backup will
only spend 40 bucks for one disk but will spend over a thousand for a
tape drive
and tapes. That's not the alternative, the altnernative is to use a
bunch of 50 buck tapes and an 800 buck drive or use a bunch of 50 buck
disks that don't need a separate drive.

I dunno about 50 buck discs, I think you have to spend a bit more if
you want external enclosures.

Why would one want "external enclosures? A Kingwin drive bay costs 25 bucks
and you pay about 14 for the trays.

If you just mean those pull-out caddy
type discs, you have to power down your PC

Maybe _you_ do, but I don't. Disable the drive, pull it, insert the new
one, enable it. SATA is designed to support hot-swap and it actually works
reasonably well.

when you install or remove
one of those things, which makes backup considerably less convenient.


Tape really does seem to be superior for backup, and VXA drives are
pretty good technology. Their main drawback is that the tapes are so
expensive. Right now I back up to HD, but am looking towards LTO.
LTO-3 has just started shipping (400 GB native!) and perhaps as a
result, there's been quite a drop in the cost of LTO-{1,2} drives and
media over the past few months.

Tape is cost effective for some purposes, not for others. If you need
_reliable_ backup then put two drive bays in your machine, attach them to a
RAID controller, backup to a RAID-1, then take one disk home and leave the
other at work. Do _that_ with tape for a reasonable cost--the software
alone will buy you quite a lot of disks, and you'll need two tape drives.

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

"Paul Rubin" wrote in message
...
"Rob Turk" writes:

Well, $200 gets you around 300 GB of hard disc space. VXA2 X23 tape
is $85/80GB so to back up the same amount of data on tape, you spend
over $300 just on the blank tape.

With tape you can select the capacity independent of the drive, keeping your
backups separate. OP could start with X10 media, which does exactly 40GB
native, for $32 each. See:
http://www.exabyte.com/products/tape/xtape.cfm

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.
Even when you want to transfer to an ISP for better rates, how do you get
your backups out? Again, for your personal MP3 collection there's no
problem. Besides, your MP3 collection is stored onto the Internet multiple
times over already.. ;^)

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

Rob

"J. Clarke" writes:
The solution is if you're backing up to HD's, use removable HD's and
make sure they're actually removed except when a backup is in
progress.

The thing is, if the machine is "hit by a virus" while the daily
backup disk is in the machine you lose that day's data, not the
previous day's. Assuming that the virus will actually corrupt a
compressed, encrypted image file in a nonrecoverable way.

If a compressed, encrypted image is corrupted at all, it's probably
unrecoverable.

The magnetic files aren't THAT strong. Neither the disk platters nor
the tape gets erased. The lightning fries the drive electronics

If the contents of the platters remain undamaged then the recovery isn't
going to be all that expensive--a circuit board swap will probably do it.

That's easier said than done. I won't say it never works, but all
attempts that I've heard of (not that many) to recover data by just
swapping circuit boards have failed. And the places that did it
charged a bundle.

If you just mean those pull-out caddy type discs, you have to
power down your PC

Maybe _you_ do, but I don't. Disable the drive, pull it, insert the new
one, enable it. SATA is designed to support hot-swap and it actually works
reasonably well.

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.

Tape is cost effective for some purposes, not for others. If you need
_reliable_ backup then put two drive bays in your machine, attach them to a
RAID controller, backup to a RAID-1, then take one disk home and leave the
other at work. Do _that_ with tape for a reasonable cost--the software
alone will buy you quite a lot of disks, and you'll need two tape drives.

I see RAID as good for crash protection but not so good for backup.
Right now as mentioned, I'm using HD's for backup but I'm not
impressed with their reliability. I'm hoping to move up to a tape
drive again sooner or later (my old DDS-2 drive's 4GB capacity is
pathetic by today's standards). I only use free software, so that's
not a significant cost component.

"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.

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

In article l,
Rob Turk wrote:
"Paul Rubin" wrote in message
...
"Rob Turk" writes:

Well, $200 gets you around 300 GB of hard disc space. VXA2 X23 tape
is $85/80GB so to back up the same amount of data on tape, you spend
over $300 just on the blank tape.

With tape you can select the capacity independent of the drive, keeping your
backups separate. OP could start with X10 media, which does exactly 40GB
native, for $32 each. See:
http://www.exabyte.com/products/tape/xtape.cfm

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.
Even when you want to transfer to an ISP for better rates, how do you get
your backups out? Again, for your personal MP3 collection there's no
problem. Besides, your MP3 collection is stored onto the Internet multiple
times over already.. ;^)

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

Rob



I like iBackup, and online services of their type, if my space
requirement fit their service, and my network bandwidth. For hime use
upostream bandwidth is frequently the bottleneck. The big plus is
instant access to data from an alternate location.

I've done busness continuity planning for Big Companies for years.
Businesses use extenal services with the potential to break the
company all the time. Contracts and escrow, etc apply, Online data
backup is no different. A business person knows that everything has
risk and the good ones know how to balance risk and gain. Any online
service that sells to businesses will have a service agreement that
addresses for privacy, accessability, etc, with non-perormance
clauses. I (as a businessman) can accept, reject, or try to customize
the contract.

Backup is part of business contingency planning and it's the job of
the Sysadmin to accuratly lay out the technical costs and risks of
various backup strategies to Sr. Management, who are the proper people
to decide how much to spend for what degree of risk. Risk is never zero.

Back to the OP's requirements, I haven't seen him state how much data
he wants to back up. If it fits on a CD, burning a daily CD (read
verified) is a pretty cheap way to do backups. I don't trust CD/DVD
media but proper practices can offset their weaknesses.

CDs are good. DLT and other enterprise tape drives are good (and
noseblead expensive) The problem in in the middle size requirement.

I backup my workstations and laptops via disk-to-disk image and
image-incremental backups to a big drive on a server, keeping multiple
generations of backup on the disk. These images are migrated to a
second disk, just in case. This disk could be in a second server
but I have not done that yet. This is for my home LAN.

In addition to image backups, I sync My Documents between a desktop
system and my laptop, sometimes several times a day. That way, if I'm
working on a deadline and my system craps out my MTTR is nearly zero,
at last as for as getting my critical work done.

I also burn important work product into a couple CDs and take them
offsite.

--

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

Don't blame me. I voted for Gore.

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.

--

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:
The solution is if you're backing up to HD's, use removable HD's and
make sure they're actually removed except when a backup is in
progress.

The thing is, if the machine is "hit by a virus" while the daily
backup disk is in the machine you lose that day's data, not the
previous day's. Assuming that the virus will actually corrupt a
compressed, encrypted image file in a nonrecoverable way.

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 magnetic files aren't THAT strong. Neither the disk platters nor
the tape gets erased. The lightning fries the drive electronics

If the contents of the platters remain undamaged then the recovery isn't
going to be all that expensive--a circuit board swap will probably do it.

That's easier said than done. I won't say it never works, but all
attempts that I've heard of (not that many) to recover data by just
swapping circuit boards have failed. And the places that did it
charged a bundle.

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.

Generally such an attempt is tried on a drive that is dead of undetermined
causes, not one on which the problem is known to be fried electronics. But
in the real world one would not try to fix that drive anymore than one
would try to fix a tape cartridge that got dropped and cracked. It's a
disposable device and you go to the previous day's backup.

The thing is, for any kind of backup system you can make up a scenario in
which it will fail. The question is how likely is that scenario and will
you care about your backups if it occurs.

If you just mean those pull-out caddy type discs, you have to
power down your PC

Maybe _you_ do, but I don't. Disable the drive, pull it, insert the new
one, enable it. SATA is designed to support hot-swap and it actually
works reasonably well.

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. I have a couple of
250 gig disks in external enclosures that I carry to client sites to back
up their disks when I'm going to do something that puts their data at risk
or am going to swap out a drive--I run them in RAID-1 so that if I manage
to destroy one I haven't lost their data.

Tape is cost effective for some purposes, not for others. If you need
_reliable_ backup then put two drive bays in your machine, attach them to
a RAID controller, backup to a RAID-1, then take one disk home and leave
the
other at work. Do _that_ with tape for a reasonable cost--the software
alone will buy you quite a lot of disks, and you'll need two tape drives.

I see RAID as good for crash protection but not so good for backup.

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. 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.

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 hoping to move up to a tape
drive again sooner or later (my old DDS-2 drive's 4GB capacity is
pathetic by today's standards). I only use free software, so that's
not a significant cost component.

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.

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

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

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.

No, but unless there's been a radical improvement in 1394-to-ATA bridge
chips since the last time I checked the performance is abysmal. Read that
twice before you start quoting me textbook figures about 1394--it could
have an infinite transfer rate and with a lousy bridge chip it would still
give poor performance in this application.

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

Rob Turk wrote:

"Paul Rubin" wrote in message
...
"Rob Turk" writes:

Well, $200 gets you around 300 GB of hard disc space. VXA2 X23 tape
is $85/80GB so to back up the same amount of data on tape, you spend
over $300 just on the blank tape.

With tape you can select the capacity independent of the drive, keeping
your backups separate. OP could start with X10 media, which does exactly
40GB native, for $32 each. See:
http://www.exabyte.com/products/tape/xtape.cfm

X10 does 40 native on a VXA-2 drive, the cheapest of which bought new goes
for 810 bucks. Doesn't work at all on a VXA-1. The best price I see on
the tapes is 23 bucks. 40 gig SATA disks in shock-mounted removable
drawers go for $64, and the tray to put it in goes for $25. So let's see
how many generations of backup we can maintain for a given dollar figure.
Just for hohos let's see what it looks like for 80 gig ($67), too, which is
as large as VXA2 ($62 for X23) goes.

Cost VXA Disk VXA Disk
X10 40 X23 80

89 0 1 0 0
153 0 2 0 1
217 0 3 0 2
281 0 4 0 3
345 0 5 0 4
409 0 6 0 5
473 0 7 0 6
537 0 8 0 7
601 0 9 0 8
665 0 10 0 9
729 0 11 0 10
793 0 12 0 11
857 2 13 0 12
921 4 14 1 13
985 7 15 2 14
1049 10 16 3 15
1113 13 17 4 16
1177 15 18 5 17
1241 18 19 6 18
1305 21 20 7 19


So until you're up to 20 generations of backup the VXA costs more than disk.
With 80 gig disk vs VXA, I'm not going to show the whole table, but the
crossover occurs at 153 generations of backup. For 120 GB you'd have to
use an X10 and an X23 for $90 vs disk in drawer for 89 and VXA _never_
breaks even, not to mention having to change media in mid stream.

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.

They can take your data hostage only if you have managed to lose it while
the dispute is going on. Seems to me that if a dispute is starting the
thing to do is go to an alternative backup strategy.

If they go belly-up
or get if they get taken over, how do you ensure you can still get your
data back. Even when you want to transfer to an ISP for better rates, how
do you get your backups out?

Why do you want to "get your backups out"? Backups are, by their very
nature, disposable. Perhaps you are confusing "archives" with "backups"?
A backup exists so that you can recover when your system fails or suffers
data loss for some other reason. All the data in a backup is online on
your system except possibly for unintentionally deleted files, which on any
decent server you can recover for quite some time even without backups. If
someone steals your backups or destroys them or anything else happens to
them, you just start a new set. Losing backups is a big deal only to the
extent that someone might obtain confidential information from them and to
the extent that there is a _tiny_ risk that your system will fail in the
interval between loss of the old backups and start of the new set.

If you _care_ about the content of it beyond that it accurately reflect the
state of your system on the day it was made, if it's not disposable, then
it's not a backup, it's an archive, and the considerations for an archive
are very different from those for a backup.

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

How about the video of my kid's first birthday?

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


Rob

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