Topic: What Backup Drive

[Mark Adams]

I'm currently building a 5.5 Server with 2 40Gb IDE Drives in Software Raid configuration.

I was considering fitting a SCSI card to act as a backup tape controller and wondered if anyone had any recommendations as to a suitable DAT drive.  I was considering the Seagate Scorpion DAT 24 Model Number : STD224000N-SB as it's over £140 cheaper than the HP Surestore DAT24i.  Is this a good choice.

Alternatively would an IDE Travan be more suitable and is it OK to have an IDE tape (and a cd-rom for that matter) as slaves on an ide channel if there is a primary and secondary master in a raid setup.

Thanks in advance.

Mark

[Paul Sahlin]

Why not take a look at the Onstream DI-30 solution? In Sweden it costs about 300 dollars.

It's an IDEtape, so you need some knowledge in linux to get it working. I've read somewhere in the forums that the new SME5.6 would include an osst.o (whichs emulates the IDE to SCSI). With SME5.6 it would work out of the box (according that author).

I'm using the HP Dat also, and it's very reliable. But it costs more....

Regards Paul

[Andres]

I'm using a DLT tape ( Compaq) 15/30 external, scsi. Works pretty good for me.
My total backup size is a littke bit more than 1GB and the total backup time is 10 minutes.

[Kelvin]

Sony has an IDE version of their AIT-1 tape drive, not too badly priced. Stores between 35GB (native) to 90GB (compressed).

And yes, you could use an Onstream DI-30 as well (and no, you don't really need to know Linux - just follow the how-to available in the how-to section here).

Daisy chaining slower IDE devices to faster ones will cause a performance degradation on the device chain (how much - depends on the devices). If you are able to get an add-on IDE controller to drive the tape drive, you could get around this problem (cheaper than an add on SCSI controller - some of the newer SCSI tape drives requires LVD capable controllers, not cheap).

Kelvin

[Mark Adams]

Paul Sahlin wrote:
>
> Why not take a look at the Onstream DI-30 solution? In Sweden
> it costs about 300 dollars.
>
> It's an IDEtape, so you need some knowledge in linux to get
> it working. I've read somewhere in the forums that the new
> SME5.6 would include an osst.o (whichs emulates the IDE to
> SCSI). With SME5.6 it would work out of the box (according
> that author).

Well Paul, I'm not a linux expert and I don't have time to wait for 5.6 so I'd rather something that worked out of the box.

>
> I'm using the HP Dat also, and it's very reliable. But it
> costs more....
>

I have enough budget for a controller and the Seagate and with backup reliability is my main concern.

Perhaps someone else has used the Seagate drive and has an opinion.

Regards

Mark

[Mark Adams]

Andres wrote:
>
> I'm using a DLT tape ( Compaq) 15/30 external, scsi. Works
> pretty good for me.
> My total backup size is a littke bit more than 1GB and the
> total backup time is 10 minutes.

Yes, but DLT is a lot more expensive that DAT is.  I'm not expecting huge backup sizes so time should not be an issue.

Regards

Mark

[Mark Adams]

Kelvin wrote:
>
> Sony has an IDE version of their AIT-1 tape drive, not too
> badly priced. Stores between 35GB (native) to 90GB
> (compressed).
>

Ok thanks, I'll check that out in the morning.

> And yes, you could use an Onstream DI-30 as well (and no, you
> don't really need to know Linux - just follow the how-to
> available in the how-to section here).
>

That sounds more promising!

> Daisy chaining slower IDE devices to faster ones will cause a
> performance degradation on the device chain (how much -
> depends on the devices). If you are able to get an add-on IDE
> controller to drive the tape drive, you could get around this
> problem (cheaper than an add on SCSI controller - some of the
> newer SCSI tape drives requires LVD capable controllers, not
> cheap).
>

Well I already have a scsi controller that E-smith detects so an add on ide would actually be more expensive for me (unless that difference in price between an IDE tape and a SCSI covers it.

Do you know how much degradation there would be?  Would this be noticeable when the slave devices were not running?

This is sort of what I expected and why the SCSI option seemed like a good idea.

Regards

Mark

[Thomas Kristensen]

Paul Sahlin wrote:
>
> Why not take a look at the Onstream DI-30 solution? In Sweden
> it costs about 300 dollars.
>
> It's an IDEtape, so you need some knowledge in linux to get
> it working. I've read somewhere in the forums that the new
> SME5.6 would include an osst.o (whichs emulates the IDE to
> SCSI). With SME5.6 it would work out of the box (according
> that author).

This is not entirely correct. The osst.o module in 5.5 works perfect with the DI-30...

My 2 cents,
Thomas

[Kelvin]

Hi Mark,

>Do you know how much degradation there would be?
>Would this be noticeable when the slave devices were not running?

Depends.

Are you using HDPARM on your drives at the moment ? If not, then you'll most likely not notice any difference at all. Even if you are, it's not easy to put your finger on how much of a degradation you'll see. A lot of factors come into it (how heavy is your server hard disk use, how much RAM -- effects caching, etc.).

Price difference between SCSI versions and IDE versions of the same tape unit here in Oz is usually in the hundreds (approx between AUD$ 200 - AUD$ 500). Cost of an add on IDE controller approx AUD$ 50.00 - AUD$ 75.00.

Kelvin

[Darrell May]

For an inexpensive and reliable tbu I highly recommend the Seagate STT22000A 20GB IDE:

http://rss.seagate.com/products/srssDrives/STT220000A-M.html

Note: I have not had an opportunity to test their 40GB IDE, so no direct comment, but I'm hopeful someone will test this and report their results:

http://rss.seagate.com/products/srssDrives/STT2401A-S.html

Next both the Onstream DI-30 and ADR2.60IDE are known to work. Depending on your SME release, minor SME modifications may be necessary.

http://www.onstream.com/

After that most all standard single SCSI tbu work.  Doesn't really matter as to whether it is DAT/DLT/AIT as long as your SCSI controller identifies it and works with it correctly as /dev/nst0.

Note flexbackup does not support SCSI autoloaders etc.

Regards,

Darrell