need a new raid array so I've done some math for the best space/cost disk to use.

[atrull]

- my 4 year old 600gb (6x120gb) array is short of space! - I'm not entirely short of cash so I've been thunking lately !

So off I go trying to find the best bang-per-buck (or gig per quid) solution to my problem.... Idealy I need to at least double my space

so.. I take a look at the big list o' disks on the scan site. pasting them into a text file gives me something in this format (with a bit of cleanup, such as no review available, call for price, etc bollocks):

LN11540
250 Gb Samsung SP2514N SpinPoint P120, IDE (PATA), 7200 rpm, 8MB Cache, 8.9 ms £42.10 £49.47

Now you're asking, what use is that ? not much

Along comes a long, inefficient grep/sed/awk expression!

cat hdd-pricelist.txt | sed s/sterling//g | sed s/gb//gi | sed '$!N;s/\n/ /'| gawk '{ disksize = $2; disknumber = 8 ; spare = 1;raidsizemax = disksize * disknumber ; raidsizeeffective = ( raidsizemax - (spare * disksize ) ) ; raidprice = $NF * disknumber ; gigsperbuck = raidsizeeffective / raidprice ; print gigsperbuck" "raidsizeeffective" "raidprice" "$1};' | sort -n

the numbers I put in mean I want to build an 8 disk array with one drive spare - typicaly in raid5 you want 1 hotspare too, but raid5 can tollerate the loss of one disk, so I could buy more disks while running with limited performance ...

now, I haven't decided whether I want sata or pata or scsi, but purely on size/cost , I end up with the following table:

gigs per buck | effective raid size | price | code
4.20741 2100 499.12 LN15140
4.40229 1750 397.52 LN11461
4.41295 1750 396.56 LN12655
4.42187 1750 395.76 LN11540

Thats more like it! LN11540 yields spintpoints p120 250gb disk for a pata array and ln12655 returns (a maxtor diamondmax 250gb) the most effective sata disk. I haven't found any cheap PATA controllers for 8 port.... yet .. and sadly the only suitable SATA controller (the excellent pci-e rocketraid 2320) wallows in at almost 200 quid.

However a 5x300/320gb sata array may be more effective given that a revo 64 5 port is barely breaking 60 quid!

Yet to work out how good the lunix/bsd support is for the revo however, let alone whether the revo is even worth 60 quid - it looks dodgy.

But anyway, now to wire in some raid controller costs to the awk face off the revo 5 disk vs the rocketraid 8 disk options.

cat hdd-pricelist.txt blah blah |gawk '{ disksize = $2; controllercost = 52.88 ; disknumber = 5 ; spare = 1;raidsizemax = disksize * disknumber ; raidsizeeffective = ( raidsizemax - (spare * disksize ) ) ; raidprice = ( $NF * disknumber ) + controllercost ; gigsperbuck = raidsizeeffective / raidprice ; print gigsperbuck" "raidsizeeffective" "raidprice" "$1" revo5disk"};' > revo5disk.txt
cat hdd-pricelist.txt blah blah |gawk '{ disksize = $2; controllercost = 185.65 ; disknumber = 8 ; spare = 1;raidsizemax = disksize * disknumber ; raidsizeeffective = ( raidsizemax - (spare * disksize ) ) ; raidprice = ( $NF * disknumber ) + controllercost ; gigsperbuck = raidsizeeffective / raidprice ; print gigsperbuck" "raidsizeeffective" "raidprice" "$1" rocketraid8disk"};' > rocketraid8disk.txt
cat revo5disk.txt rocketraid8disk.txt | sort -n

so, sticking to satas..


3.00084 1750 583.17 LN11461 rocketraid8disk
3.00579 1750 582.21 LN12655 rocketraid8disk
3.00907 2100 697.89 LN14417 rocketraid8disk
3.03141 1000 329.88 LN12903 revo5disk
3.05642 1000 327.18 LN11544 revo5disk
3.05782 1000 327.03 LN5457 revo5disk
3.05826 1200 392.38 LN12595 revo5disk
3.06526 2240 730.77 LN14162 rocketraid8disk
3.06694 2240 730.37 LN14911 rocketraid8disk
3.07448 1280 416.33 LN13503 revo5disk
3.14436 1000 318.03 LN13120 revo5disk
3.15792 1280 405.33 LN13468 revo5disk
3.18441 1000 314.03 LN11035 revo5disk
3.2169 1200 373.03 LN14417 revo5disk
3.2522 1280 393.58 LN14162 revo5disk
3.25426 1280 393.33 LN14911 revo5disk
3.31862 1000 301.33 LN11461 revo5disk
3.32524 1000 300.73 LN12655 revo5disk

[atrull]

so anyone got any further suggestions ?

I'd also need a fatarse new case if it were an 8 disk array pands suggested a CoolerMaster stacker, but there is also a case called a Codegen 8011 which looks quite cheap, 7 or 8 bays - I can't quite tell!

mobo/cpu/ram is already in hand.

[chuckskull]

If you find a 6 or 8 sata port NF4 board, thats an 8port SATA RAID right there. Something like http://www.scan.co.uk/Products/Produ...oductID=225008

With 6/8 250gig drives should sort your probs right out. Of course you'll have to sell your current mobo, but that just makes the whole thing cheaper

Thermaltake armour is good if you want lots of space, bit expensive though.

[atrull]

Originally Posted by chuckskull

If you find a 6 or 8 sata port NF4 board, thats an 8port SATA RAID right there. Something like http://www.scan.co.uk/Products/Produ...oductID=225008

With 6/8 250gig drives should sort your probs right out. Of course you'll have to sell your current mobo, but that just makes the whole thing cheaper

Thermaltake armour is good if you want lots of space, bit expensive though.

f'n brlliant thinking that fellow!

now to just make sure all 8 ports can 'raid up' and in particular..to raid 5.

[atrull]

Originally Posted by atrull

f'n brlliant thinking that fellow!

now to just make sure all 8 ports can 'raid up' and in particular..to raid 5.

can't do that dave.

the 8 ports are split over the nf4 controller and the Silicon image controller

however, on the brighter side, I have found an alternative to the rocketraid pci-e - it is however even more expensive!
The Areca ARC-1210 PCI-Express
might try to find a cheap supplier in europe for this

[atrull]

So, pci-e 8sata raid5 capable controllers

SuperTrak EX8350
Areca ARC-1210
Rocketraid 2320

[chuckskull]

Originally Posted by atrull

So, pci-e 8sata raid5 capable controllers

SuperTrak EX8350
Areca ARC-1210
Rocketraid 2320

Not used the other two, but I had an areca a while back, was good. Shame about the mobos not being able to do RAID 5 over the 8 ports.

[atrull]

already got a promise sx6000 handling my current array, so fancy a change. think it'll be the rocketraid really.

anyway, going to give it two months to see where hdd prices meander.

[herulach]

Originally Posted by atrull

gigs per buck | effective raid size | price | code
4.40229 1750 397.52 LN11461

3.00084 1750 583.17 LN11461 rocketraid8disk

I May be being dim, but how does adding 200 pound to the cost make the second one work out cheaper?

[5aboy]

why dont you get seagate 7200.10 320gb drives - they are very good and have good £/gb.

[arthurleung]

Originally Posted by atrull

So, pci-e 8sata raid5 capable controllers

SuperTrak EX8350
Areca ARC-1210
Rocketraid 2320

Just to let you know 1210 is 4 port not 8 port, you're looking at 1220 which is double the price...

[dave87]

Originally Posted by herulach

I May be being dim, but how does adding 200 pound to the cost make the second one work out cheaper?

Thats actaully showing an icrease in price - as he is getting less GB/pound spent

[atrull]

indeed.

Just thinking about hdds is stupid, you need to consider the array controller cost too.

[ExceededGoku]

on a similar note any good PCIE 4 port controllers?

[atrull]

thats an idea 2x 4port pcie sata raid5 in jbod. of course you lose twice the disk space if you have two separate raid5s..

bumhug.

[herulach]

Originally Posted by dave87

Thats actaully showing an icrease in price - as he is getting less GB/pound spent

doh, i knew id be being daft, for some reason i had it in my head that that was pounds/gbyte.