raid hard drive issue

1: Yes, if its truly a raid1 then both drives contain exactly the same inforamtion.
2: No form of raid is a backup. Raid's main purpose (aside from raid0) is UPTIME. When a drive fails, the system stays up.

- A true backup is a copy that is not connected to the pc nor power. It will survive a virus attack, power issues, user error like deleting files or formatting the wrong disk, windows updates killing your system... its is highly advisable to have more then one backup of your important files and keep one of them off-site. You never know when your house will catch on fire (trust me).

An issue you may have is incompatibility between raid controllers. AMD,Intel, Asmedia, Marvel... are generally not compatible with each other. sometimes you can't even go to a newer model in the same brand and have compatibility. Do not forget to turn on raid mode in the bios if you use motherbd raid.

Windows raid is different, it should detect it and be compatible without issue. Motherbd should be in normal AHCI or Sata mode (AHCI preferred)

1. This depends on the RAID controller. If you're using the motherboard RAID, the new motherboard may talk differently to it.
Yes, each drive would (hopefully) have a full set of the data. But it may not actually work as a RAID 1 until it is rebuilt with the new controller.

2. It is not a backup.
The OS and the user sees one volume and file. There is no 'second copy'.
It only helps in the rare case of a physical drive fail, and you really need the system to continue running 24/7.
Any other form of data loss....its gone.
Accidental deletion, corruption, virus, ransomware...RAID 1 does nothing for that.
Delete, and its gone.

Which controller is this raid from?
- A dedicated controller should be no issues moving to a new motherbd as long as the OS has drivers for it.
- Motherbd raid usually works as long as the new motherbd uses the same manufacturer controller for the sata ports (Intel, AMD, Marvell...)
- Windows raid (storage spaces) usually works with Windows

Let us know more details of the current setup and the future server and we could provide further assistance but it sounds like you've got the jist of it.

Lastly - some backup is way better then none. Music & Movies aren't critical to me so I only back mine up once. I can always get them again. LoL
My family pics & videos - are a whole 'nother ballgame.

This may be the simplest way to make the change without having to go through a proper backup. And yes, RAID1 is NOT a backup system.

IMPORTANT QUERY: I am assuming that the system you want to move is NOT your boot device. That is, this RAID set is for data only, and the new system will have another boot device to start up from. If that is NOT true - if this system would have to serve as the boot device in the new system - TELL US! That would make a BIG difference in what can be done.

READ the user manual for the RAID system you are using now. If you are using the RAID facilities built into your mobo, that may be a separate document on RAID management included on the CD that came with your mobo, OR available for free download from the website of your mobo maker. Either way, ensure that it is the manual for YOUR mobo, because others may be different.

What you're looking for is this. Most RAID1 management systems have several tools for handling problems. Among them is a tool to BREAK the RAID1 array. This will basically re-write some important management data at the beginning of each of the two HDD units, making both of them separate and independent HDD's. Each will have ALL of their data, and each will be accessible normally as a HDD, so now you have TWO identical copies of your data that really CAN be accessed without any RAID system. If you can do that and verify that the two drives operate normally, you're in a safe position. (One way to verify after you've done this is to remove one of the drives and verify that you can run your system with only one of those drives installed.)

NOW you can afford to migrate the drives into the new system, Since they are NOT RAID volumes, whatever new system you put them into will be able to read them. BUT install only one of those drives. Then READ the RAID manual for the NEW system and look for the tools to ADD a SECOND drive to an existing drive full of data and create a RAID1 array from those two. After that is working, make sure you know how to identify the first HDD that is already installed. THEN shut down and install the second HDD unit. Use the RAID management system to add that second drive and make the pair into a RAID1 system. Normally this will actually destroy all the data on the newly-added second drive and copy all the stuff from the first drive over to it, to ensure that the two units have identical data. Once that is done, you MAY have to ensure that the driver for a RAID system is installed in the Windows OS of the new system, in order to access that array.

This process avoids having to find a way to make the new RAID management system understand the way data was stored by the old system. It does that by transplanting only a "standard" HDD full of data, and then having the NEW RAID system establish the new RAID1 array.