RAID confusion on the net

J

junknstuff

Hi Fellas!

As i'm working towards unloading some media onto a FreeNAS box, I'e been doing some research and it has lead me into circles!

First and foremost, I have decided to go with a software based RAID5 solution to forego any hardware dependencies should my hardware become faulty.

Secondly, I have been looking for a motherboard with on-board RAID5 support. This is where I am getting confused because:
1) I read an article online that said I should DISABLE my motherboard's hardware RAID since we will be using software RAID
2) If this is the case, do I even need a board with onboard RAID controller at all? (in this case, any board with enough sata ports for my drives will work, right?)

CLIFF NOTES:
* I want to do a software RAID 5 set up using FreeNAS
* Do I need a motherboard that supports RAID5 or can I use any mobo with enough SATA ports for my drives?

SUPER CLIFF NOTES:
* Software RAID doesn't require any hardware RAID controller what-so-ever: YES/NO?

I appreciate all the help you guys can offer! I'll poke around the site some more, been trolling for awhile :stud
 
In general any mobo that has "raid" is a software raid. True hardware raid usually requires a extension card(pci|pci-e|pci-x) with memory and a cpu. Usually the "raid" integrated into a bios is not very good and more than often require a windows OS for a driver, so my general suggestion would be to stay away from any motherboard/bios raid and use either true hardware or true software raid's.
 
i appreciate the replies!

my question still has gone unanswered though:
do i need a board that supports RAID even though i won't being it since i will be using RAID provided by Linux?

meaning, can i use any board with 6sata ports and Linux will handle the RAID for me? regardless of native RAID support on the mobo itself?

my initial thought is yes, but i would need your help to confirm this so i'm not throwing money out the window :)
 
For OS maintained software raid nothing is needed from the mobo other than the availability of IDE/SATA/SCSI ports on the board. BUT if your mobo has RAID support on some ports(most do these days) disable it in your bios as it could interfere with the raid supported by your OS.

The OS will see individual disks(as usual for non raid setup's) and then you create a raid layer above the disks you want to use.
 
junknstuff said:
* I want to do a software RAID 5 set up using FreeNAS
* Do I need a motherboard that supports RAID5 or can I use any mobo with enough SATA ports for my drives?
Click to expand...
You do not need a raid board for this.
SUPER CLIFF NOTES:
* Software RAID doesn't require any hardware RAID controller what-so-ever: YES/NO?
Click to expand...
Soft raid works better if you don't use a raid enabled motherboard.

(not strictly true, it's just that you don't have to turn it off, which saves a step.)
 
fronclynne said:
Soft raid works better if you don't use a raid enabled motherboard.

(not strictly true, it's just that you don't have to turn it off, which saves a step.)
Click to expand...

Really? IMO this "hardware RAID on the motherboard" is simply ignored by BSD (and other POSIX systems) because it does not exist.
 
If the data that you want to put in that NAS system is valuable to you you should AVOID the following ideias :

Software RAID
Software RAID from motherboard - BIG BIG Mistake
RAID 5

Software RAID will give you trouble sooner or later.

Motherboard software RAID is a no no, if the motherboard stop working you will have to find another motherboard with the same model an pray to work.

RAID5 - If 2 disks goes bad, say bye bye to all your data.

I Recommend Hardware RAID (3Ware or Adaptec).

For RAID I recommend RAID6 - http://www.hardwaresecrets.com/article/314
 
AWESOME replies guys! I really appreciate the quick responses as I'm working towards getting this up and running ASAP!

Maurovale, you bring up a very good point. I'll read into RAID6 a little more and try to make my decision. However, I decided to go the Software RAID route because the hardware raid cards are WAYYY over my budget right now (probably something i'll upgrade later down the line, or perhaps for a new box) and also because i wanted hardware independence should a failure occur.

Nonetheless, opinions and ideas are always welcomed and i appreciate it!

For those that are wondering, no major life important data is going on the box, just media for streaming to a few machines �jr
 
If you willing I would steer you towards having a look at ZFS for "raid". For future expansions.

There are a lot of cool features for this file system one is that it negates the need for expensive hardware RAID cards(and problems with them), while you still have the security of a full raid6(called raidz2 in zfs). There is some work going on in FreeNAS 0.7 to stabilize this or you could use freebsd 7.1 as is, however it's still in experimental mode. I already use ZFS for a 2TB raidz2 "tank" using freebsd 7.0.
 
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