hi,
im planning to buy a couple of 4tb drives (most likely buy external seagate units and pull them out of the enclosures since for whatever reason they are cheaper than internal ones) and I want to set them up in RAID 1 for backup of data (photos/video footage etc) via onboard mobo controllers from a future build.

ive never done any sort of raid setup before.

some questions:

since i have not yet built the system (havent even bought parts aside from case and PS), but will buy the drives first, can I use them for backing up data BEFORE building the desktop and setting them up for RAID1?
in other words: do I need to format both drives when setting up RAID 1?
or can I keep data on one and have the data copied onto the other drive in the RAID1 setup process?

another question:
I may want to try setting up the build in a dual boot/hackintosh setup (probably pay someone to set it up since I just dont have the time to do all the research in how to make a hackintosh) and I plan on having a dedicated SSD drive for each OS (win7 and osX) but my question is: will both operating systems be able to access and write to the RAID1 array? or do data drives need to be formatted differently for each operating system?
if above is not possible I may skip on the idea of going dual boot/hackintosh but I thought it might be worthwhile to try since ive never had a mac and primary reason for this build will be a DAW and video editing system.

thanx

This depends on the specific RAID implementation. In many cases you can go from a single drive to a RAID1 and keep the data, but it is not a sure thing. I would not count on this working, even if your RAID of choice supports it.


It would be quite difficult, but not impossible to share a RAID between Windows and OSX. Software RAID is probably out as are likely most "fake RAID" controllers. You would probably need a real hardware RAID card that is compatible with both Windows and OSX. This would add a fair bit to your build cost and otherwise be a waste being used for just RAID1.

After the RAID hurdle you would need to use a compatible filesystem. For modern OSes the best choice is probably exFAT. NTFS would probably also work. FAT32 is the most compatible, but it would be unwieldy on any decent sized disk.


If you are going to do any serious work then I would skip the hackintosh or just have it around for fun. There are lots of good DAW and video editing programs for Windows.

If you really want to go Windows/hackintosh dual boot then I would highly suggest you skip the RAID. Use one single drive internally formatted as exFAT or NTFS and keep the other drive as an external backup.

It is a sure thing if you set up your drive as a degraded RAID1 array. I've done it several times. If it wasn't a sure thing, recovering from failure of one of the drives in an array wouldn't be a sure thing either. OK, it's not 100% safe since any user can issue the wrong command and any drive can fail anytime but in principle it is solid.


I do not know the implementation shipped with those OS but a decent software RAID implementation is able to work on partitions which means you can share a drive between two or more OS without issues. But then, we are talking about Microsoft and Apple so I wouldn't take decent implementations for granted.

edit: oh, "share a RAID"... so it's not the drive that's going to be shared between two RAID arrays, right? Yeah, that's probably impossible or unreliable. Sorry for the brain fart but I don't think it makes sense not to share the drive which is why I read it wrong.
The whole plan seems poorly thought out. If I wanted to use a separate OS drive, I'd probably put the data drives in RAID1 in some kind of NAS. Problem goes away. Alternatively, use one of these cheap external drives externally and backup to it. It's safer than RAID (for most purposes) and eSATA is fast.

honestly the only reason i want to try it/osx is because of logic pro. so i guess i dont really need to access data drive via osx. perhaps ill buy a one tera drive and format it for osx and just keep audio samples on that? but it would be good to access at least some sort drive from both OSes to move files (say i want to back up my finished song onto the data array (and going external than internal through win7 seems like a long way around workaround)

so youre saying the only solution is to buy another external box?
if it can be done externally isnt there a way to do it internally?

No, you can use the box which comes with the drives you were planning to buy. Or you can recuse an old enclosure.

If you want to go the NAS (or equivalent) route, you can reuse an old computer, purchase parts to upgrade an old computer or buy a ready-made NAS box.
One of the points of a NAS in your situation is to isolate the RAID logic from your operating systems which would of course require separate hardware if you want to do it properly*. You can probably do it internally and cleanly with a proper RAID card (which comes with its own computing hardware) but I would prefer to use a NAS.
I do not believe you really have a good use for RAID however, much less for using the same RAID array in Windows and Mac.

*you can have a virtual NAS running in a VM on the same computer as your Mac or Windows OS... but I wouldn't recommend it


You can set up non-RAID partitions on your big drives. There's no need for a separate internal drive for this purpose. There's no need for separate system drives either by the way.

An advantage of storing your data externally whether it be on a NAS (or equivalent) or on s simple external drive is safety.

RAID is no backup. So you'd need to have that external drive anyway. As HFat said, why bother with something you do not know enough about to keep running?

If you do it internally, then you have no security for data loss whatsoever. Seems pretty silly to put everything in one place and have it blown away if your power grid sends nice greetings from overcurrent country.

Off-topic but does stuff like that actually happen in Germany? I've been running 24/7 equipment without protection for most of the century and I haven't had a single incident of this type.
Failing drives, user error, unsafe configurations, hardware introducing bit errors, PSU failures and whatnot including untraceable software/RAM issues... sure. But drives killed by the electrical utility? Never.

I agree with you in principle and I've done it many times myself. However, it sounds like octeuron would be doing this with his only copy of the data. It will probably work just fine, but I'd still consider it too risky without backups first.


Windows can do software RAID on partitions just fine, but it requires dynamic disks which other OSes don't support well. It would probably be possible for Linux or BSD to use them, but OSX is the problem here. Same with FakeRAID, Windows and Linux/BSD are fine but OSX is the oddball.

Worst case (and not necessarily related to germany) could be a blowing PSU causing more components to die.

Have had this once with an old PC ages ago, PSU puffed and died, replaced and found out, that the HDD had died too.

How often and how much of a risk that special case poses is beyond my knowledge. But calculating this risk is up to everyone, some may bother some may not.

If you have only one copy, doing *anything* with your data is risky... except backing it up.
I wouldn't play with data if I had only two copies. If it was even marginally important, I'd want three copies before trying out new stuff on it (more if the data is actually valuable).

If washu guessed right, I have only one recommendation for you octeuron: backup now!


I was only fishing for info about the grid quality in Germany.

A PSU dying and taking out a drive is something I witnessed as well. But it was a PSU crappier than anyone on SPCR would consider (I hope). Some Microsoft pusher had put this cheapo in a server which had no backups (it had an unreliable cheap tape drive that wasn't even compatible).
Usually, a PSU death only causes the same issues you'd get if you yanked out the power cord. It may be different if your grid is bad. I've got no experience with that.

With software raid you're stuck with the OS that made it. With fakeraid you depend on OS driver support, and it may be not compatible across operating systems as well. With real hardware raid you're screwed if the card dies, as you need to find an identical one to access your data.
Tbh i'd use only one drive internally and another as an external backup drive