Invisible wrote:
> scott wrote:
>>> No, the limitation I'm running into now is space, not time.
>>
>> Buy some bigger tapes then, or more of the current ones?
> 
> DDS only goes up to a maximum of 80 GB. My server holds 103 GB. Time to 
> move to a different tape technology - but which one? There are many to 
> choose from.
> 

I'm backing up 180 GB at the moment

The storage space for data is 250GB.

The backup space available is 250GB - but not everything in the data is 
backed up.

Backups take 2.5 hours to run at the moment.


Tom

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Invisible wrote:
> DDS only goes up to a maximum of 80 GB. My server holds 103 GB. 

Sorry. Something looks wrong in these numbers. 103 GB? You don't mean 
103T?  I can't even go to the store and buy a hard drive that small, 
unless it's a laptop hard drive. You could mirror the whole drive every 
day of the week for about $500.

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>> DDS only goes up to a maximum of 80 GB. My server holds 103 GB. 
> 
> Sorry. Something looks wrong in these numbers. 103 GB? You don't mean 
> 103T?  I can't even go to the store and buy a hard drive that small, 
> unless it's a laptop hard drive. You could mirror the whole drive every 
> day of the week for about $500.

Yes, 103 GB. That's 4 drives holding 36 GB each in a RAID-5 array. 
Hence, effectively 3 x 36 GB. (Windoze reports it as 103 GB. I guess the 
drives aren't exactly 36.0 GB or something.)

Given that we have 103 GB and it's about 20% full so far, what in the 
name of God would we need 103,000 GB for? And last time I checked, SCSI 
drives are [still] damn expensive. Sure, you could probably get a 300 GB 


I guess we *could* back up to a hard drive. But I'm not really that keen 
on the idea. We would have to shut the server down to connect the drive, 
start it back up again, format the drive, copy all the data, somehow 
verify the data, shut the server down, disconnect the drive, put it 
somewhere safe, and start up the server again. Every single night. No 
thanks...

I don't have any hard evidence to back this up, but isn't power-on the 
most common time for a HD to fail? (Rather like lightbulbs.) Wouldn't 
the constant cycling tend to wear them down? Hmm, mind you, I guess it's 
no worse than all the other PCs here that get switched on each morning...

The other small problem is that 30 harddrives presumably take up 
slightly more space than 30 DDS tapes. ;-)

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>> What do you use to back up data? I'm not talking about permanent 
>> archival, I'm talking about rolling backups so that if a small 
>> meteorite hits your server room, you don't loose all the data you're 
>> working on.
> 
> At work? LTO-II with robotic library capable of 14 tapes.

Yeah, looks like we'll be getting an LTO-I robotic library (8 tapes?)

I guess I should go look up prices for LTO tapes...

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> Given that we have 103 GB and it's about 20% full so far,

So your 80GB tapes should be fine for a while yet then???

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scott wrote:
>> Given that we have 103 GB and it's about 20% full so far,
> 
> So your 80GB tapes should be fine for a while yet then???

...except that my tapes are 36 GB?

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>> So your 80GB tapes should be fine for a while yet then???
>
> ...except that my tapes are 36 GB?

Oh sorry I thought you meant the maximum size tapes your system could take 
was 80 GB.

Even so, if you're using 20GB of data, surely that fits onto a 36 GB tape ok 
with plenty of room for expansion over the next months/years?

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Invisible wrote:
>>> DDS only goes up to a maximum of 80 GB. My server holds 103 GB. 
>>
> 
> I guess we *could* back up to a hard drive. But I'm not really that keen 
> on the idea. We would have to shut the server down to connect the drive, 
> start it back up again, format the drive, copy all the data, somehow 
> verify the data, shut the server down, disconnect the drive, put it 
> somewhere safe, and start up the server again. Every single night. No 
> thanks...
> 
> I don't have any hard evidence to back this up, but isn't power-on the 
> most common time for a HD to fail? (Rather like lightbulbs.) Wouldn't 
> the constant cycling tend to wear them down? Hmm, mind you, I guess it's 
> no worse than all the other PCs here that get switched on each morning...
> 

This is a pretty narrow view of what can be done with a HD for a backup.
USB, Firewire, hot-swap bays, hot-swap raid enclosures, etc....
All of which don't present the problem that you describe.


Backing up to a HD is not ideal for most situations.
I'm not going to try to persuade you to do it.

It comes with its own problems that other media doesn't have.
It isn't mainstream.


> The other small problem is that 30 harddrives presumably take up 
> slightly more space than 30 DDS tapes. ;-)
> 

That depends on your backup strategy.  If it requires 30 separate media, 
then yes, storage space can be a premium.  Just tuck one or two near QA 
girls desk and say 'hi' each time you get one ;-)



Tom

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Tom Austin wrote:

>> The other small problem is that 30 harddrives presumably take up 
>> slightly more space than 30 DDS tapes. ;-)
>>
> 
> That depends on your backup strategy.  If it requires 30 separate media, 
> then yes, storage space can be a premium.  Just tuck one or two near QA 
> girls desk and say 'hi' each time you get one ;-)

Right. I'm sold!

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http://www.zazzle.com/MathematicalOrchid*

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scott wrote:
>>> So your 80GB tapes should be fine for a while yet then???
>>
>> ...except that my tapes are 36 GB?
> 
> Oh sorry I thought you meant the maximum size tapes your system could 
> take was 80 GB.

Not quite, no. The maximum tape size our system can take is 36 GB. The 
next model up will handle 80 GB, and there *is* no higher model after 
that. So I think we need to move to another technology.

> Even so, if you're using 20GB of data, surely that fits onto a 36 GB 
> tape ok with plenty of room for expansion over the next months/years?

And in other news, I CAN'T DO MENTAL ARITHMETIC! >_<

(I have 59 GB of data to back up. Obviously this doesn't fit on a 36 GB 
tape. Although to the system's credit, with the compression it does it 
actually *almost* fits... But when we get to the point where we're using 
nearly 103 GB of storage, we don't want to be using 36 GB or even 80 GB 
tapes, ideally.)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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