Buy External Hard Drive: Advice & Tips

[darkar]

Hello, need help in buying an External Harddrive.

In your opinion, which is a good external harddisk manufacture?

And will it be a good thing to buy it off ebay?

and which connection will be better? USB 2.0 or firewire?

Thanks a lot ~

 

[Anttech]

Just buy a caseing and your own disk, youll save money!

 

[PerennialII]

I've drifted to using the option 'other' ... Lacie.

 

[imabug]

I don't buy a lot of HDs, but of the ones I've worked with, Maxtors and Seagates have failed least often. At work we've had a number of IBM/Hitachi Deskstar drives fail. I've also seen a few WD drives taken out. My last home computer purchase was motivated by a WD drive that went south on me (although it lasted a few years before it died).

 

[Bayou Tiger]

I've been very pleased with the SmartDisk USB 2.0 60 GB. It has enabled the carrying around and quick access all of my work, school, and home backup info (much better than the occasional backup CD). The advantages of this drive are that it does not need a separate power source and that it is only the size of a pocket calculator. Plus, it is not very expensive (maybe $150). I highly recommend it but do not have experiences with other stuff for comparative purposes.

 

[franznietzsche]

Western Digital, then Maxtor or Seagate.

 

[Pengwuino]

Holy jesus get western digital. If women were anything like these 2 external hard drives i have, I'd actually want to get married.

 

[franznietzsche]

Holy jesus get western digital. If women were anything like these 2 external hard drives i have, I'd actually want to get married.

Ok then...

 

[xPAGANx]

Seagates have a 5 year warranty. They are the most reliable drives around. If you value your data go with Seagate.

 

[rho]

Just buy a caseing and your own disk, youll save money!

Yeah i'd agree with that get a external SATA casing that can take two drives and put a small WD raptor (10,000 rpm ) and a big WD Caviar RE in it.

 

[-Job-]

One disadvantage of getting your own case is that they can get a little bulky (not very very much, but a little), other than that they're pretty good, you can easily recycle hard drives or switch from internal to external, plus it's actually cheaper.

 

[franznietzsche]

Yeah i'd agree with that get a external SATA casing that can take two drives and put a small WD raptor (10,000 rpm ) and a big WD Caviar RE in it.

Why would you put the small raptor in a raid with a caviar? That's a waste of drive space, since you'de only get double the capacity of the single raptor. Better off with two raptors if you're putting them in a raid (although, since performance is not likely his issue, two caviars would be better for storage).

 

[graphic7]

Why would you put the small raptor in a raid with a caviar? That's a waste of drive space, since you'de only get double the capacity of the single raptor. Better off with two raptors if you're putting them in a raid (although, since performance is not likely his issue, two caviars would be better for storage).

This all depends on how your logical volume manager does RAID 0. If you intend on striping, then, yes, the slices do have to be equal and you'd only get double the capacity of the smallest drive; however, if your logical volume manager offers a concatenation, you could use drives of different sizes and get an overall capacity of the sum of the smallest drive's capacity, plus the capacity of the larger one.

I'm not sure you'd want to create a logical volume out of disks that are in an external enclosure you intend on moving around, anyways. You would have to take your logical volume configuration to each system and use it, so that's not very practical (depending on the operating system and logical volume manager, it can be quite painful forcing it to use a configuration it didn't setup initially); however, if the external enclosure is going to be stationary, this wouldn't be a problem.

 

[franznietzsche]

This all depends on how your logical volume manager does RAID 0. If you intend on striping, then, yes, the slices do have to be equal and you'd only get double the capacity of the smallest drive; however, if your logical volume manager offers a concatenation, you could use drives of different sizes and get an overall capacity of the sum of the smallest drive's capacity, plus the capacity of the larger one.

When you say concatenation are you talking about JBOD, or a variant of a RAID 0? I know you can combine the two drives into one with JBOD (though why you'd use drives with such different read/write speeds is beyond me), but its sounds like you mean RAID 0 (striping) with concatenation? So then, the first 158 GB (twice the size of the raptor) would be striped across the two, and then the remaining space on the caviar would be usable, but not striped, right?

 

[graphic7]

When you say concatenation are you talking about JBOD, or a variant of a RAID 0? I know you can combine the two drives into one with JBOD (though why you'd use drives with such different read/write speeds is beyond me), but its sounds like you mean RAID 0 (striping) with concatenation? So then, the first 158 GB (twice the size of the raptor) would be striped across the two, and then the remaining space on the caviar would be usable, but not striped, right?

A JBOD has nothing to do with RAID levels or logical volumes -- it's merely "(J)ust A (B)unch (o)f (D)isks", crammed into an enclosure with one or more controllers. So, even a two-drive external enclosure could be considered a JBOD.

Some logical volume managers are smart enough to stripe the space on each of the drives that are equal, and the extra space is concatenated, so, yes, you can do that. With other's you either do concatenation or striping, not both. Of course, striping is much faster than concatenation, as you're writing blocks to each of the drives in the array sequentially. With concatenation, you write the blocks to one drive or slice until that slice or drive fills up, then you start writing to the next one, so concatentation gives you the same amount of performance as writing to a single drive (it gets a little more tricky calculating the performance if you're using multiple controllers). On the other hand, if you're fortunate to have multiple controllers, say n of them, and you spread the drives out across the controllers, you can get n*(the bandwidth of a single controller) with striping, assuming all the controllers can read and write at the same speed and the controller-disk ratio is 1:1.

 

[franznietzsche]

A JBOD has nothing to do with RAID levels or logical volumes -- it's merely "(J)ust A (B)unch (o)f (D)isks", crammed into an enclosure with one or more controllers. So, even a two-drive external enclosure could be considered a JBOD.

I've always seen JBOD used to refer specifically to a concatenation of several physical drives into a single logical drive.

Some logical volume managers are smart enough to stripe the space on each of the drives that are equal, and the extra space is concatenated, so, yes, you can do that. With other's you either do concatenation or striping, not both. Of course, striping is much faster than concatenation, as you're writing blocks to each of the drives in the array sequentially. With concatenation, you write the blocks to one drive or slice until that slice or drive fills up, then you start writing to the next one, so concatentation gives you the same amount of performance as writing to a single drive (it gets a little more tricky calculating the performance if you're using multiple controllers). On the other hand, if you're fortunate to have multiple controllers, say n of them, and you spread the drives out across the controllers, you can get n*(the bandwidth of a single controller) with striping, assuming all the controllers can read and write at the same speed and the controller-disk ratio is 1:1.

All of this I know, I was simply confused as in your previous post it seemed like you were referring to using RAID 0 and concatenation with the same two drives. Although the thought just occurred to me of partitioning the second drive, so the first partition matches the smaller drive, doing a RAID 0 with the smaller drive and the first partition, and then concaneting the second parition with the RAID 0. Would this work?

 

[graphic7]

I've always seen JBOD used to refer specifically to a concatenation of several physical drives into a single logical drive.

Sounds like a gap in terminology. Sure, you're "concatenating the capacities of" several disks into a single logical volume, yes, but you're not using "concatenation" to write to the disks. I'm sitting next to a JBOD, myself, at the moment, and I'm certainly not using concatentation (actually, it's a Sun Storedge A5200 with 14x36.6GB fibre-channel drives doing RAID 0+1 -- 7 of the drives are striped and the other 7 are mirroring them.)

All of this I know, I was simply confused as in your previous post it seemed like you were referring to using RAID 0 and concatenation with the same two drives. Although the thought just occurred to me of partitioning the second drive, so the first partition matches the smaller drive, doing a RAID 0 with the smaller drive and the first partition, and then concaneting the second parition with the RAID 0. Would this work?

Sure, this would work, but, like I said, some volume managers are smart enough to do this for you. This can be either good or bad, as you don't always know the volume manager is doing it.