RAID 1 Question

[Tomiking]

Lets say I have 2 drives in a RAID 1 array, and one of the drives and the raid controller dies. Would I be able to recover all of my data from the raid array by taking the drive that is still working from that computer and simply connecting it to a different computer and accessing it in an operating system environment?

 

The reason I'm unsure about this is because I know that with more complex levels of RAID, the raid controller dying means the data wont be accessible by just plugging all those drives into a different PC, however due to the nature of RAID 1 (it being just a mirror) I don't see how this would be an issue.

 

Thanks

[Vitalius]

Yes, it will work fine. From an OS' perspective, it's just a normal drive. No RAID at all. That's what RAID 1 is. Nothing more than a mirror, meaning that it isn't dependent upon any other drive to access the data on a specific drive. i.e. you can take it out of the RAID and plug it into another computer and it "just work".

[Tomiking]

Yes, it will work fine. From an OS' perspective, it's just a normal drive. No RAID at all. That's what RAID 1 is. Nothing more than a mirror, meaning that it isn't dependent upon any other drive to access the data on a specific drive. i.e. you can take it out of the RAID and plug it into another computer and it "just work".

Thanks

[WhatTheQuack]

I think you will still be able to retrieve the data using a different PC, because RAID 1 is literally just a copy of the data on each drive. But if you are in the middle of a file transfer when the drive and controller fails, some data might be corrupted. (but only the data that is being transferred)

[TheProfosist]

yes all good

[madcow]

I think this depends on the raid controller. If you have a hardware raid controller it will likely have a proprietary format that only it understands. Even single disk JBODs created on a hardware raid controller often cannot be read directly by the OS. You can still recover the raid in a degraded state but you would need an identical working controller in the new machine and run an import.

 

HBA and software raid - you are fine as long as you run the same software

Hardware and motherboard raid - I'm thinking no

[Ahnzh]

I think this depends on the raid controller. If you have a hardware raid controller it will likely have a proprietary format that only it understands. Even single disk JBODs created on a hardware raid controller often cannot be read directly by the OS. You can still recover the raid in a degraded state but you would need an identical working controller in the new machine and run an import.

 

HBA and software raid - you are fine as long as you run the same software

Hardware and motherboard raid - I'm thinking no

THIS!

 

Unless you really want the very minimal performance boost of a hardware raid (which is just like some very few IOPS) you won't want to run a hardware RAID at all. In the beginning hardware raids were a good thing because software raid runs off the cpu. In earlier days the power that was drawn from the CPU was a lot larger portion of the available CPU power (back in single core days) and required process priority. You generally were running either a dual CPU server (to get 2 threads) or bought a hardware RAID card which essentially is a computer on a board. You got a system OS, you got a CPU, you got RAM, a DOM to boot from and it just handles the data in the background. Nowadays you got 123451234 Core CPUs and the workload is around 5% of a single core. Not even worth mentioning. Like i said, the performance is comparable and what matters after that is what happens if something fails. RAID rebuilds are done easily with both hardware and software raid, but if the controller gives up you right run into serious problems. In case of hardware raids you need an identical controller, and even then it's not guaranteed to recover all data. For software RAIDs it's easier since the RAID data is saved on the drives and not in a chip. Just plug it into a system with the same OS/RAID-software you were using and click rebuild. And it allows you to use things like S.M.A.R.T. for example. That makes Linux usage far more appealing (Linux software RAIDs are preferably used to Microsoft software RAIDs. Disable the RAID chip in the BIOS. It's basically a software raid it's building but it's handled by a controller, so you lose the advantage of closer integration into the OS of each drive.

 

 

In every aspect i would go for software raids.