i agree.
also keep in mind a JBOD setup is essentially one large disc with multiple of odd size discs as subsystem. one fails, just about all your data is gone.
an onboard SAS controller which supports 8 drives, supports 8 drives no matter the number of ports.
SAS as well as SATA support multi lane cabling, it is a lot more common and was first used in SAS.
miniSAS is just a smaller interface (connector) also called SFF-8086 and/or SFF-8087

i don't think it would be a waste of money and/or time to sell of the old drives and replace them with newer ones. 1.5tb drives can be had for about $100 bucks these days.
imo it would rather be a waste to spend the time and effort to find space and compatibility for older drives which in numbers consume much more energy and space

look at it this way... Say you buy 20 1TB drives today... it gets you 20TB of storage for $2000 but what if only fill 5TB each year?

lets instead just by drives as necessary.

This year 6 1TB drives = $600
next year 3 2Tb drives = $300
2 years out 2 4TB drives = $200
3 years out 1 8TB drive = $100

after 3 years you have 28TB of storage and you spent $1200

which is a waste of money again?

looks like we have more money left, lets keep going.

4 years out you need to replace the 6 1TB drives you bought the first year and you need more space for more movies so you buy a 16TB drive $100

now you've spent $1300 total and have 38TB of storage.

year 5: $1400 total and have 64TB of storage after replacing the 3 2TB drives. still under cutting the "all at once" method after 2 rounds of drive replacements and we've got over 3x the space!

Yes I suppose you are right saying it was a waste of money was a stupid statement.

What about the RAID itself, isn't it very difficult and time consuming to add extra drives to a RAID array? and I didn't think you could mix multiple disk sizes? or is that a thing of the past? I've read about some different NAS' that claim to add disks very quickly and can use multiple sizes but I haven't kept up to date with on board controllers.

Also BoT. you were saying SATA also supports Multilane cabling? I did not know this. I thought SATA had to be a direct controller>device connection I wasn't aware that you could multilane.. could you please explain to me how that works?

Rhys Callender said:

yes it is a pain, but who says every drive has to be part of the same array? You could set yourself up on a drive buying "plan" and make each years drive purchases their own array. Use RAID 5 for cases where you're using 3 or more drives and RAID 1 in cases where you only have 2 drives in the array... You'll want some fault tolerance because with as many drives as you're running you can bet you'll have a few failures.



It depends on how the drives are setup... with a JBOD array you probably can add drives to the array fairly easily... with a RAID 5 or RAID 1 probably not.

the areca controller as many others allow for mixed size drives. the back draw is that the array will default to the smallest size drive in the array.
example: you have 1x 500gb + 2x 400gb + 2x 320gb in a array. you will essentially end up with 5x 320gb. so plenty of lost space. however, higher end cards like the areca's i pointed out, do not determined the raid by physical drives but rather by volumes/ logical drives.
so you still could get almost all of the space of the 5 drives, much smaller loss and the areca controller will tell you which raid options are available with your setup and what maximum space you can get out of them.

adding additional drives to an array is not that difficult, the controller allow for live expansion of the array. which means you just drop in the drive while the computer is running and enter raid config console. once you see your drive, you add it to the array, expand the volume and about an hour later ... bam. all is well

multi lane is actually used by the card i posted about. the areca 1280ML supports both SAS and SATA drives and cables and adapters are included in the card.
the multi lane used here is the miniSAS SFF-8087 i believe.
here is a link to the card on newegg, if you check out the pictures you can see the adapters and ports
http://www.newegg.com/Product/Product.aspx?Item=N82E16816151027

silicon image also has decent cards which are quiet a bit cheaper and also support multi lane.

addonics is a big supplier and distributor of those
http://www.addonics.com/products/multilane/
here is another one .. cooldrives
http://www.cooldrives.com/sata-raid1.html

they mostly use it for external applications

Tyan makes awesome mobo's, maybe you should check them out.