Linux Debian support - Need backup hardware suggestions

Author

Need backup hardware suggestions

Madhusudan Singh

2004-09-10, 8:45 pm

Hi

I am exploring various solutions for reliable backup for my exclusively
Linux populated LAN (3 machines).

What would provide me with the best value for money combination when the
important considerations for me (barring cost) are :

1. Speed of backup. (I do not want to spend hours backing up a few ten
GB's).
2. Number of cycles of backup (durability).
3. Total volume that can be backed up.
4. Portability.

?
I need a solution that can backup upto 30 GB or so. What is better ? Tapes
or external USB harddisks ?

Thanks.

Davide Bianchi

2004-09-11, 2:45 am

On 2004-09-11, Madhusudan Singh <spammers-go-here@spam.invalid> wrote:
> What would provide me with the best value for money combination when the
> important considerations for me (barring cost) are :
> 1. Speed of backup.
> 2. Number of cycles of backup (durability).
> 3. Total volume that can be backed up.
> 4. Portability.

Tapes are still the best solution (IMHO) when the total volume doesn't
surpass the capacity of a single tape, an Exabyte (as someone else
suggested) can easily backup up to 100 Gb with a transfert rate of
30 Gb per hour, tapes are reusable and the MTBF is greater than
disks.

Davide

--
Pohl's law:
Nothing is so good that somebody, somewhere, will not hate it.

Madhusudan Singh

2004-09-11, 2:45 am

Davide Bianchi wrote:

> On 2004-09-11, Madhusudan Singh <spammers-go-here@spam.invalid> wrote:
>
> Tapes are still the best solution (IMHO) when the total volume doesn't
> surpass the capacity of a single tape, an Exabyte (as someone else
> suggested) can easily backup up to 100 Gb with a transfert rate of
> 30 Gb per hour, tapes are reusable and the MTBF is greater than
> disks.
>
> Davide
>

How much would a 100 GB Exabyte drive with tape cost ? If it is too
expensive, then it might not be right for me.

Davide Bianchi

2004-09-11, 2:45 am

On 2004-09-11, Madhusudan Singh <spammers-go-here@spam.invalid> wrote:
> How much would a 100 GB Exabyte drive with tape cost ?

You'd better ask to a dealer or retailer for that. If it doesn't matter,
you can even found the drive used on e-bay. Tapes is a different matter,
since you want more than one (usually) and they need to be replaced at
least once a year, even if I run backups on the same tape for over
3 year without problems. But in the end, you make backups for security,
so it's better to switch the tapes every now and then.

When my company replaced the old Mammooth-2 tape with a tape library
(8 tapes, automatic change mechanism, 800Gb minimum capacity) we spent
a good 6000 euro worth of equipement.

Davide

--
Very few profundities can be expressed in less than 80 characters.

Robert E A Harvey

2004-09-11, 5:45 pm

Madhusudan Singh <spammers-go-here@spam.invalid> wrote in message news:<ejs0d.25$r41.886@news.itd.umich.edu>...
> Hi
>
> I am exploring various solutions for reliable backup for my exclusively
> Linux populated LAN (3 machines).

Try an AIT tape drive - they are available as external scsi if you
want - and will hold 100GB with a supposed write time of 24GB per
minute

DAT drives are cheaper, but typically hold one tenth of the capacity
and go at one tenth of the speed.

There is something to be said for using disks instead of tape, but the
number of generations you can keep is limited, whereas you can keep
buying blank tapes. If you just want the latest snapshot, then disks
may be worth considering. A bit of a cron job can save images
unattended, provided you have solved the problem of backing up any
databases.

you mentioned portability - there is no need to move the backup
device, you can access it over the network from the other machines.

John-Paul Stewart

2004-09-11, 5:45 pm

Robert E A Harvey wrote:
> Madhusudan Singh <spammers-go-here@spam.invalid> wrote in message news:<ejs0d.25$r41.886@news.itd.umich.edu>...
>
>
>
>
> Try an AIT tape drive - they are available as external scsi if you
> want - and will hold 100GB with a supposed write time of 24GB per
> minute

24GB per minute??? No way. That would be 400MB/sec, or way faster than
any of today's hard drives, faster than any SCSI interface, faster even
than a 32-bit/33MHz PCI bus. The specs I've seen for AIT-3 show 24MB
(not GB) per second or just under 1.5GB per minute. (That's assuming
2:1 compression, too.)

http://www.storagebysony.com/produc...main.asp?id=170

Robert E A Harvey

2004-09-11, 8:45 pm

John-Paul Stewart <jpstewart@binaryfoundry.ca> wrote
> 24GB per minute??? No way. ... The specs I've seen for AIT-3 show 24MB
> (not GB) per second or just under 1.5GB per minute.
quite right. That was a typo. I;ve been working nights!

Madhusudan Singh

2004-09-11, 8:45 pm

Thanks to everyone who responded. I am afraid that my question might have
left some erroneous impressions ("barring price" was meant more as an
attempt to find the best technical solution after which I would find the
cheapest of the set of solutions suggested).

I administer a small home network and price is an important consideration
for me. So, solutions that run into more than a few hundred dollars are not
acceptable for me.

So, in light of that, what would be better ? An external USB hard drive, or
USB tape drives ? I am willing (after exposure to the prices) to have a few
hour long backup times as long as the backups are reliable and portable.

John Thompson

2004-09-12, 5:45 pm

["Followup-To:" header set to comp.os.linux.misc.]
On 2004-09-12, Madhusudan Singh <spammers-go-here@spam.invalid> wrote:
> Thanks to everyone who responded. I am afraid that my question might have
> left some erroneous impressions ("barring price" was meant more as an
> attempt to find the best technical solution after which I would find the
> cheapest of the set of solutions suggested).
>
> I administer a small home network and price is an important consideration
> for me. So, solutions that run into more than a few hundred dollars are not
> acceptable for me.
>
> So, in light of that, what would be better ? An external USB hard drive, or
> USB tape drives ? I am willing (after exposure to the prices) to have a few
> hour long backup times as long as the backups are reliable and portable.

My solution was to buy a used DLT tape drive on eBay. I just got another
DLT-IV drive (20/40GB capacity) for about US$25. Tapes, often new, are
also available quite reasonably. Many companies are moving away from
their DLT-III and DLT-IV hardware and media because they need higher
capacity. This equipment is still quite rugged and very reasonably
priced on the used market.

You could probably put together a very decent DLT-based backup system for
about US$200, including tape drive, cables, SCSI adaptor, and sufficient
tapes for multiple backups.

--

-John (john@os2.dhs.org)

Madhusudan Singh

2004-09-23, 9:30 am

Thanks to everyone that responded. Driven by price, and by the knowledge
that things that are harder to do usually do not get done regularly, I have
purchased an Iomega HDD 80 GB with USB 2.0. Tape drives require manual
intervention while I could presumably just set up a cron job to
periodically back up stuff to the HD. It cost me $119 (buy.com) and thus
was far cheaper than even used decent tape hardware (I found no prices
lower than about $250).

Now I have a few questions :

1. To maximize speed of backup, which filesystem should I format the new HD
with (btw. how do I do it ?) ? ResierFS or ext2 or something else. I have
read that ReiserFS is better for large backups.

2. What would be a good tool to use ? Amanda or just a custom script that
backs up the stuff ? I have to backup two machines - one with 80 GB max HD
(actual usage is less than 40 GB) and another which is 40 GB max HD (actual
usage is less than 25 GB)

Dan Skinner

2004-09-23, 9:30 am

Madhusudan Singh <spammers-go-here@spam.invalid> wrote in message news:<2reeffF1a6hkiU1@uni-berlin.de>...
> Thanks to everyone that responded. Driven by price, and by the knowledge
> that things that are harder to do usually do not get done regularly, I have
> purchased an Iomega HDD 80 GB with USB 2.0. Tape drives require manual
> intervention while I could presumably just set up a cron job to
> periodically back up stuff to the HD. It cost me $119 (buy.com) and thus
> was far cheaper than even used decent tape hardware (I found no prices
> lower than about $250).
>
> Now I have a few questions :
>
> 1. To maximize speed of backup, which filesystem should I format the new HD
> with (btw. how do I do it ?) ? ResierFS or ext2 or something else. I have
> read that ReiserFS is better for large backups.
>
> 2. What would be a good tool to use ? Amanda or just a custom script that
> backs up the stuff ? I have to backup two machines - one with 80 GB max HD
> (actual usage is less than 40 GB) and another which is 40 GB max HD (actual
> usage is less than 25 GB)

A word of caution:
Data stored on a drive of any type that is connected to the computer and
has power applied is a copy of the data, NOT BACKUP!!!
If all you want is a copy, then just cross copy files on the network.
If you want backup, the first thing you need to do is figure out how you
are going to restore your system after the the computer system is
destroyed by fire or flood. The plan that results will limit the backup
media to a few choices. A USB drive would not be on my short list, but if
you can figure one into your recovery plan, go for it.
Regards...Dan.

Rich Grise

2004-09-29, 5:45 pm

On Wednesday 22 September 2004 03:59 pm, Madhusudan Singh did deign to grace
us with the following:

> Thanks to everyone that responded. Driven by price, and by the knowledge
> that things that are harder to do usually do not get done regularly, I
> have purchased an Iomega HDD 80 GB with USB 2.0. Tape drives require
> manual intervention while I could presumably just set up a cron job to
> periodically back up stuff to the HD. It cost me $119 (buy.com) and thus
> was far cheaper than even used decent tape hardware (I found no prices
> lower than about $250).
>
> Now I have a few questions :
>
> 1. To maximize speed of backup, which filesystem should I format the new
> HD with (btw. how do I do it ?) ? ResierFS or ext2 or something else. I
> have read that ReiserFS is better for large backups.

I'd format it with reiser, just 'cuz.

> 2. What would be a good tool to use ? Amanda or just a custom script that
> backs up the stuff ? I have to backup two machines - one with 80 GB max HD
> (actual usage is less than 40 GB) and another which is 40 GB max HD
> (actual usage is less than 25 GB)

I haven't used any custom backup programs, I usually just copy the stuff
I want to save to some other drive somewhere. Like most people, I usually
back up my critical data right after a system crash. ;-)

It certainly wouldn't be hard to write a backup script, although there are
probably lots of programs available. Try a http://www.google.com search on
something like "backup software linux" or something.

Good Luck!
Rich

Madhusudan Singh

2004-09-29, 5:45 pm

Rich Grise wrote:

> On Wednesday 22 September 2004 03:59 pm, Madhusudan Singh did deign to
> grace us with the following:
>
>
> I'd format it with reiser, just 'cuz.
>
>
> I haven't used any custom backup programs, I usually just copy the stuff
> I want to save to some other drive somewhere. Like most people, I usually
> back up my critical data right after a system crash. ;-)
>
> It certainly wouldn't be hard to write a backup script, although there are
> probably lots of programs available. Try a http://www.google.com search on
> something like "backup software linux" or something.
>
> Good Luck!
> Rich

Thanks for your response.

I indeed chose reiserfs as a little more digging revealed that it was much
faster than ext2/3.

I wrote a small script for myself after fiddling with storeBackup.pl and a
few other scripts.

Its a simple rsync driven backup now. I put it in the cron job and now it
works.

There is an issue with hotplug however. Since the USB drive is a backup
drive (due apologies to the purists), I usually keep it disconnected from
the system and powered down.

In my /etc/fstab, in accordance to the dmesg o/p, I have declared it to
correspond to /dev/sda1. However, when I connect the drive to a running
system, it gets detected as /dev/sdb1 since I have another mass storage
device (a 100 MB zip drive) which gets the sda since it boots up with it.

Is there a way to automatically detect (in a script) where the true /dev
assignment is ?

Дамјан Георгиевски

2004-09-29, 5:45 pm

> In my /etc/fstab, in accordance to the dmesg o/p, I have declared it to
> correspond to /dev/sda1. However, when I connect the drive to a running
> system, it gets detected as /dev/sdb1 since I have another mass storage
> device (a 100 MB zip drive) which gets the sda since it boots up with it.
>
> Is there a way to automatically detect (in a script) where the true /dev
> assignment is ?

You could probably make a small hot-plug script, that makes a custom link
from the real device to for ex. '/dev/backup', you'll have to find a way to
identify the device, and there should be more than one way to do that. You
could even auto-mount it under '/mnt/backup' in the same script.

I think there are some scripts that do exactly this on freshmeat.net, search
for usb-mount.

--
дамјан

Actually, Microsoft is sort of a mixture between the Borg and the Ferengi.

Neil Woods

2004-09-29, 5:45 pm

Madhusudan Singh <spammers-go-here@spam.invalid> writes:

> In my /etc/fstab, in accordance to the dmesg o/p, I have declared it to
> correspond to /dev/sda1. However, when I connect the drive to a running
> system, it gets detected as /dev/sdb1 since I have another mass storage
> device (a 100 MB zip drive) which gets the sda since it boots up with it.
>
> Is there a way to automatically detect (in a script) where the true /dev
> assignment is ?

You could label the devices. You can then add LABEL=Backup (for example)
to your /etc/fstab. See e2label(8) or reiserfstune(8).
--
Neil

Madhusudan Singh

2004-09-29, 8:45 pm

Neil Woods wrote:

> Madhusudan Singh <spammers-go-here@spam.invalid> writes:
>
>
> You could label the devices. You can then add LABEL=Backup (for example)
> to your /etc/fstab. See e2label(8) or reiserfstune(8).

Thanks for your response.

Would e2label work for a reiserfs partition ?

E2LABEL(8) E2LABEL(8)

NAME
e2label - Change the label on an ext2/ext3 filesystem

Neil Woods

2004-10-01, 5:45 pm

Madhusudan Singh <spammers-go-here@spam.invalid> writes:

> Neil Woods wrote:
>
>
> Thanks for your response.
>
> Would e2label work for a reiserfs partition ?

No. You will have to use reiserfstune on reiserfs partitions. Assuming
you have already mounted your zip drive on /dev/sda1, and your backup
(usb) drive is therefore on /dev/sdb1 (and plugged in!), you can:

reiserfstune --label Backup /dev/sdb1

This drive can therefore be referred to in mount operations and in
/etc/fstab as Backup. (Use the `-L' option to mount in your script.)

Use `LABEL=Backup' instead of the actual device name in your /etc/fstab.

--
Neil