i have a server that i built and have been running very well for a year or so. But now it is time to upgrade the storage space. at the mo, it has a 60gb HDD for the OS and programs, and a seperate 1TB HDD for the storage. i've just bought 2 x 3TB HDD's, and i am fully prepared to use one as a complete mirror. binning off the 1TB for other duties. with the view of upping the storage capacity in the future. i also have bought a Raid Card as well, as the MOBO i am using doesnt have enough SATAS and doesnt do raid. will mirrior be my best choice, or do i do a striped backup? can i utilise the 1TB in this to offer better backup?
RAID10 requires four drives, and it's pretty useless anyway. With RAID1 you only get the storage space of one drive while the rest are mirrored. RAID5 is probably what you want. With this, you get the storage space of all but one drive (in this case 6TB), and the array can withstand one drive failure. edit: Sorry, I misread the OP. You have two drives. In that case there's only one option -- RAID1.
Only two options with only two drives, RAID 1 & 0. RAID 1 is mirroring - a copy of the data will be stored identically on both drives and one you have one drive fault tolerance - one drive can fail and you will not loose any data. With two 3TB drives you will have 3TB of space available (before formatting) RAID 0 is striping - both drives will be used store data but the data is not fault tollerant, if EITHER drive fails ALL data is lost. A full regular backup is recommended if you run this setup. With two 3TB drives you will have 6TB of space available (before formatting) Once a RAID Array is setup you cannot make any changes to it (add/remove drives or enlarge/shrink the array) without deleting the array and re-creating it from scratch - this involves TOTAL data loss on any drives in the array. If you want to be able to change your setup there is another option you could use... 'Drive Pooling', unlike RAID which is hardware based this is a software solution, which can combine multiple drives into a virtual pool of one or more virtual drives. Realtime parity or partity shanpshots can be scheduled, these will generate a checksum type backup of the data so you get fault tolerance also. There are a few different pooling soltutions that offer drive pooling: www.stablebit.com www.drivebender.com http://snapraid.sourceforge.net/ http://windows.microsoft.com/en-gb/windows-8/storage-spaces-pools
If you're looking for data protection with two drives, you're better off setting one up as a backup for the other, preferably in another system or an external enclosure. RAID1 is all well and good for an all out drive failure, but does nothing to save you from creeping corruption or accidental (or malicious) deletion.
I'd be tempted to use a combination of the approaches suggested above. Use the two 3TB drives in RAID1 (mirror one 3TB drive with the other to protect against drive failure) and then use the 1TB drive as a backup for part of the mirror - the things that you really, really don't want to lose (through corruption or deletion etc)
