Raid

[yngndrw]

Hi,

I've searched around lots but I've never really found the answer to some questions I have.

1) If I have a RAID 0 array and the drives are removed from the computer, does it matter which order they are reconected to the SATA connectors ? What about connecting them to totally different connectors ? (Assuming that them connectors are on the same controller and support RAID) What about if they are on a new controller ?

2) If I have either RAID 1 or RAID 5 and a disk breaks, I replace it with a new (blank) drive. What has to be done in order to get the array working again ? Is it automatic ? Does this depend upon the chipset / controller ?

3) How much faster is RAID 5 compaired with RAID 0 ? Is it the case that 2 drives in RAID 0 is the same speed as three drives in RAID 5 ?

4) What's the best motherboard / chipset for onboard RAID ? In terms of performance and features ?

Thanks for any help, these questions have bugged me for a long long time !
-Andrew.

[zanzabar]

on board controlers u will want an intel ich9r, and the responces only apply to intels and high/midrange cards may not apply to a jmicron or NV chipset

1) it dont matter what ports u reconnect to so long as its all of the original drives on the controller

2) u can use the intel matrix (or other bios for brand xxx should have it) and restore or in windows/linux/unix go into the raid console and add the drive to the raid volume

3) raid 5 is slower than raid0 by about 20-40% but faster than raid 1 or no raid by 60-80%

4) answered above, ich9r or ich10r if u wait till february (i think that they will be similar but 9r is a sure shot)



in the intel raid console i think that u can also convert raid0 to raid5, i know that u can at the enterprise lvl but i think that they implemented it into the 9r

[yngndrw]

Thank you very much for your replys.

Only other thing is regarding #1, what would happen if you were to connect most but not all drives up. (In RAID0, 1 and 5, Say you had a cable loose, for example.)
Would the array fail as a whole, or would you still be able to use any parts the array still had access to ?

Oh and what kind of chips would you suggest for a RAID card ?

Thanks again,
-Andrew. :)

[xMrBunglex]

if you lose a drive in a RAID-0 array you won't be able to boot. RAID-0 has no redundancy. i've heard people say RAID-5 can be as fast as RAID-0 (depending on the controller), but i've also heard that RAID-5's can rebuild themselves at inconvenient times, causing slow downs. i've never used RAID-5 so i have no idea if you can control that or how it works.

[s1nykuL]

This should help:

http://www.pcguide.com/ref/hdd/perf/raid/levels/singleLevel0-c.html

[Brian MP5T]

RAID 0 For speed and size with low cost.
You need to back up the data

RAID 5 For redundancy but you still have to back up the data.

I have two RAID 0 Arrays of 4 Drives each.
They mirror each other.
If one fails, I can rebuild it from the other.
It offers speed and at $80 for a 500GB drive, It's under $400.00 for a 2TB server. $800.00 for 2TB with backup.

[yngndrw]

Thanks for input guys. (Also for the link, I'm looking through it now.)

I'm leaning towards having a 6x 300GB RAID 5 array. I just think having two mirrored 3x 300GB RAID 0 arrays is a bit of a waste of money for me seems as this is just for my home / gaming computer. I don't really have the time to do real backups etc (Other than for any work I have on here, which I do onto a memory card.), having said that if something goes wrong I want to be able to restore it without having to reinstall everything. (EDIT: Just read the bit on that site about RAID 5's performance, will look into RAID 10 / 01 - Just a shame that I can't find 500GB HDDs for anywhere near $80 over here. :()

It's also been a relief to hear that RAID drives can be hooked up in any order, as previously when rebuilding my computer it was a bit un-nerving not knowing what would happen if I connected them in a different order.

So thanks again to everyone for their input and answering my questions. :)

[zanzabar]

what drives are u looking at make sure that u get some stuff with fast spinups like samsung or hitatchi

[yngndrw]

I was actually looking at Seagate drives because I've heard they are the best, but I don't know that much about disk drives in general. Samsung or Hitatchi's would both be cheaper to, hmm.

Are Seagate's really any better ?

[stevecs]

For RAID I would say yes but that's just based on my experience. Of all the drives I've used over the past 20+ years the seagate ones though not always the fastest have always performed very well under RAID or heavy loads. Whenever I've been 'wooed' by lower prices I've always had to pay for it in my time in troubleshooting.

As for general reliability and description of the raids I have a breakdown in the spreadsheet I posted here: http://www.xtremesystems.org/forums/showthread.php?t=150176&page=2

it really comes down to how much can you afford and what your performance/reliability goal is as to what raid level you want.

[Brian MP5T]

Thanks for input guys. (Also for the link, I'm looking through it now.)

I'm leaning towards having a 6x 300GB RAID 5 array. I just think having two mirrored 3x 300GB RAID 0 arrays is a bit of a waste of money for me seems as this is just for my home / gaming computer. I don't really have the time to do real backups etc (Other than for any work I have on here, which I do onto a memory card.), having said that if something goes wrong I want to be able to restore it without having to reinstall everything. (EDIT: Just read the bit on that site about RAID 5's performance, will look into RAID 10 / 01 - Just a shame that I can't find 500GB HDDs for anywhere near $80 over here. :()

It's also been a relief to hear that RAID drives can be hooked up in any order, as previously when rebuilding my computer it was a bit un-nerving not knowing what would happen if I connected them in a different order.

So thanks again to everyone for their input and answering my questions. :)


That does not make sense...

Raid 5 should still be backed up. nothing will prevent corruption in the FAT...

[zanzabar]

I was actually looking at Seagate drives because I've heard they are the best, but I don't know that much about disk drives in general. Samsung or Hitatchi's would both be cheaper to, hmm.

Are Seagate's really any better ?

ive never had good luck with maxtor or seagate, and samsung makes the fastest 7200rpm and they dont have a high failure rate (a little high doa but not failure affter u test them) and samsung ses 2-3 platters in their drives so they spin up much faster than other brands like WD who use 3-6 platers in most of their 7200rpm drives



i like the 500GB samsungs the best out of all of the sata2 7200rpm