RAID Help

[Syndacate]

Hey,

I just built a new system which has a 132-BL-E758-A1 mobo in it. I have 3 1TB hard drives. I wanted to put my OS on one, and put important documents on the "second" - which would be a RAID1 mirror between the other 2TB. That or a RAID5 would be nice.

I planned on using the Hardware RAID, as I typically mess around with a few OS's and I'd like it to be fully functional on all of them.

I RAID'ed them together as a RAID1 mirror in the BIOS but when I booted a Live CD (don't have an OS on it yet) it read 3 individual drives. My friend said it may need drivers, but I thought since it was purely hardware it should be fine. Am i wrong on this? Is this some kinda weird ass hybrid system? Or am I expecting too much from this hardware? I'd like to exclude software completely, but RAID cards are incredibly expensive.

Any input would be greatly appreciated.

 

[Adidas4275]

Put willneed drivers for the os of your choice for your raid controlller.
Not sure why the live cd says it's 3 drives.

 

[Syndacate]

It's complete hardware though, why would drivers be required at all?

In my BIOS it says "Data" (the name of the RAID), which is a RAID1 (that is mirror, right??). Then I go into gparted live CD (didn't have a CD drive so couldn't do anything but USB boot), just went in, typed:

ls -l /dev/sd*

And it showed all 3 drives, I thought that should only show two .

Or maybe it's something in that linux reads the physical drives instead of the RAID volumes as the device files, but I was thinking that since it's hardware RAID it should create a level of abstraction, and any OS should only see it as one drive. Also, even if Linux does read it by the individual drive ID's or something, how the hell would I be able to mount it?

Gah, this is stupid, any help would be greaetly appreciated.

EDIT:
What is "Put" ?

 

[AreEss]

The problem is Linux and how it handles certain RAID cards, which is extremely broken. Also, ICH10R is not "pure hardware" - it's hybrid file system and software RAID. The actual array is a file system managed by the ICH10R on all disks in the array.

Chances are good that the actual array is under a completely difference device name, and that you need to mount that device. But you'll still be able to mount the /dev/sdN devices and introduce data corruption and data loss there. Or it's simply refusing to recognize the ICH10R as a Matrix RAID. Or it "supports" the Matrix RAID but requires you do array creation in Linux (rendering it incompatible with other OSes, IIRC.) There is a great deal of oddity with the Matrix RAID in Linux.

I would check behavior with a FreeBSD 7.2-RELEASE CD, and see if the array gets picked up correctly there - it'll be listed as /dev/ar0-256.

 

[Menelmarar]

It's complete hardware though, why would drivers be required at all?

In my BIOS it says "Data" (the name of the RAID), which is a RAID1 (that is mirror, right??). Then I go into gparted live CD (didn't have a CD drive so couldn't do anything but USB boot), just went in, typed:

ls -l /dev/sd*

And it showed all 3 drives, I thought that should only show two .

Or maybe it's something in that linux reads the physical drives instead of the RAID volumes as the device files, but I was thinking that since it's hardware RAID it should create a level of abstraction, and any OS should only see it as one drive. Also, even if Linux does read it by the individual drive ID's or something, how the hell would I be able to mount it?

Gah, this is stupid, any help would be greaetly appreciated.

EDIT:
What is "Put" ?

I've only dealt with Intel/Highpoint controllers and Windows. During Windows install, and within the OS, it is as you would expect, the RAID0 or 1 array only shows up as a single drive.

Don't know why Linux would be any different... AreEss sounds like he knows what he's talking about, very interesting.

 

[Syndacate]

So basically there's no way to completely abstract the RAID array from the OS's?

Because that's what I was looking for, complete and 100% abstraction via hardware. Guess I had the wrong idea of a hardware vs software RAID or something, this hybrid stuff is crap, IMO.

 

[AreEss]

So basically there's no way to completely abstract the RAID array from the OS's?

Because that's what I was looking for, complete and 100% abstraction via hardware. Guess I had the wrong idea of a hardware vs software RAID or something, this hybrid stuff is crap, IMO.

That depends on the OS. The reason the Matrix RAID requires specific drivers to do specific things is because of the way it operates. The drivers entirely have control of how the Matrix RAID is presented to the OS.
As an example, in Windows, a RAID1 array is presented as a single logical drive. Same for RAID5. Above HAL you can see the drives, but only via the Matrix RAID drivers. (This is so it can flag things like disk write errors in the event log.) In FreeBSD, the behavior is similar - you can actively manage your Matrix RAID with software, but each array will only be presented as /dev/arN. You can access raw devices via the cam layer.
Linux? Well. They can't decide what the hell they want to do with Matrix RAID, so it's changed at least a half dozen times. Your guess is as good as mine as to whether or not it'll properly abstract, or it'll play games with creating devices and denying permission, or it'll play pretend RAID. ICH10R support may not even be in the kernel, leaving you high and dry anyways.

 

[Syndacate]

That depends on the OS. The reason the Matrix RAID requires specific drivers to do specific things is because of the way it operates. The drivers entirely have control of how the Matrix RAID is presented to the OS.
As an example, in Windows, a RAID1 array is presented as a single logical drive. Same for RAID5. Above HAL you can see the drives, but only via the Matrix RAID drivers. (This is so it can flag things like disk write errors in the event log.) In FreeBSD, the behavior is similar - you can actively manage your Matrix RAID with software, but each array will only be presented as /dev/arN. You can access raw devices via the cam layer.
Linux? Well. They can't decide what the hell they want to do with Matrix RAID, so it's changed at least a half dozen times. Your guess is as good as mine as to whether or not it'll properly abstract, or it'll play games with creating devices and denying permission, or it'll play pretend RAID. ICH10R support may not even be in the kernel, leaving you high and dry anyways.

Ah, that's really stupid. I was hoping that a hardware RAID could COMPLETELY abstract the RAID so any OS would all see the RAID1 array as one drive, and it'd be as simple as that. Guess I expected too much out of hardware or something .

Guess I'll have to find an alternative to RAID now, like nightly backups from one drive to the next, which I'm not really a fan of, but it's better than relying on software for it, as that tends to be very platform dependent, and drivers usually don't play nice with each other, and I use too many diff OS's to rely on drivers playing nice with each other.

Damn.



Oh well.

 

[AreEss]

Ah, that's really stupid. I was hoping that a hardware RAID could COMPLETELY abstract the RAID so any OS would all see the RAID1 array as one drive, and it'd be as simple as that. Guess I expected too much out of hardware or something .

No, hardware RAID can do that, depending on drivers. There's an absolute necessity for per-drive access by those drivers alone, and management GUIs through the drivers. Reason being, it's the only way to do online sparing, online replacement, etcetera. Any properly functioning RAID driver will either completely obfuscate or restrict access to the individual drives. Having visibility doesn't necessarily mean having actual access - it's just Linux that tends to ignore that step. (Data integrity is about the lowest concern in their happy little hallucination.)

Guess I'll have to find an alternative to RAID now, like nightly backups from one drive to the next, which I'm not really a fan of, but it's better than relying on software for it, as that tends to be very platform dependent, and drivers usually don't play nice with each other, and I use too many diff OS's to rely on drivers playing nice with each other.

Damn.



Oh well.

RAID is not a backup. RAID is to ensure a single drive failure does not kill your data. If data gets corrupted, you are hosed on both sides of the mirror. That's how it works. It's a raw block level copy of drives (or effectively so on Matrix RAID.)
Like I said; this is solely a Linux problem. Try FreeBSD 7.2-RELEASE, see how it behaves. If you have /dev/ar* devices, then you're golden. If you don't have /dev/ar*, then something is wrong. ICH10R is definitely in 7.2-REL. I'm willing to bet ICH10R support isn't in the Linux kernel you're booting, which will well and truly hose you.

 

[Menelmarar]

RAID is not a backup.

QFT!
This can't be iterated enough. It does not protect from many of the potential losses of data:
accidental deletion (user error)
virus
corruption
fire/natural disaster
theft
etc.

 

[Syndacate]

No, hardware RAID can do that, depending on drivers. There's an absolute necessity for per-drive access by those drivers alone, and management GUIs through the drivers. Reason being, it's the only way to do online sparing, online replacement, etcetera. Any properly functioning RAID driver will either completely obfuscate or restrict access to the individual drives. Having visibility doesn't necessarily mean having actual access - it's just Linux that tends to ignore that step. (Data integrity is about the lowest concern in their happy little hallucination.)



RAID is not a backup. RAID is to ensure a single drive failure does not kill your data.

Yeah, I got that, I meant backup as in since I wanted to mirror the drives, run a nightly program that syncs the drive I dump crap on to the second drive (that would have been in the mirror) - like a half-assed RAID1.

If data gets corrupted, you are hosed on both sides of the mirror. That's how it works. It's a raw block level copy of drives (or effectively so on Matrix RAID.)
Like I said; this is solely a Linux problem. Try FreeBSD 7.2-RELEASE, see how it behaves. If you have /dev/ar* devices, then you're golden. If you don't have /dev/ar*, then something is wrong. ICH10R is definitely in 7.2-REL. I'm willing to bet ICH10R support isn't in the Linux kernel you're booting, which will well and truly hose you.

I'm usually using Linux so this problem would apparently be a big one. I haven't had any data get corrupted like that, but yeah, I'd be willing to risk that over risking one of my drives bricking. I haven't had an FS get corrupted on me, I *have* on the other hand, had drives fail. I just wanted to protect a bunch of sensitive data and I thought this would be a good way to do it.

QFT!
This can't be iterated enough. It does not protect from many of the potential losses of data:
accidental deletion (user error)
virus
corruption
fire/natural disaster
theft
etc.

I am NOT looking for any of the above. I am simply looking for a safety measure in case one of the drives craps out - so that I don't lose everything. I'd like this safety measure to be on sight as I'm not about to upload all my sensitive stuff to somebody else's server.

It's real simple, I'm not looking for backup solutions, so I don't need you to iterate that for me. I'm simply looking for a place to put all my work, my pictures, important documents, receipts, etc. The problem with dumping this all on one drive is that if that drive goes, I'm hosed. So I wanted to mirror them using RAID1, so that if one drive crapped out, I wouldn't lose anything.

Though I intended on doing this via hardware. I didn't want to use software because I didn't want it to be a RAID1 mirror on one OS and 2 separate drives on the other, and god only knows what happens if whatever driver decides to checksum them against each other and it fails. I was simply looking for a mirrored disk on all OS's, so I can put my important/sensitive stuff on there, whether it be code, or a receipt, or whatever and not worry about it going bye-bye because the drive craps out, and being able to access it from all OS's as it would be in a common format such as NTFS.

What i meant by backup was simply that if I can't get the RAID1 to work, I'd have to go with a higher level software solution (not drivers), like copying all non-hash-matching files from one drive, to the other, or "backing up" one drive to the other. So that at the these nightly backups would yield nightly mirrors of each other.