Poll of the Day > Home NAS Users: Anyone use RAID for their NAS?

(+) Yeah! (+)

Which RAID do you use for your array? Personally looking for storage and data safety over performance.

RAID 10. need 4x drives, but theoretically get 2x performance and redundancy, and 2x 1 drive capacity. (4 1TB drives -> 2TB total storage.) can lose any 1 drive, and even a second drive if it's not the wrong one (the mirror of the first, 1/3 chance). (I personally have 2 machines with this and really is how I've had the same volume for 10 years now; I've replaced a drive twice in those 10 years I think.)

friend of mine likes RAID 5 the most. Can't remember exactly, but I think you need 3 drives or more. 1 drive is parity drive. get (n-1) capacity (4 1TB drives -> 3TB total). can lose any 1 drive. I think performance increases linearly based on number of drives, but apparently there is a large write penalty since it has to check parity before writing and then update parity after writing.

Sahuagin posted...

RAID 10. need 4x drives, but theoretically get 2x performance and redundancy, and 2x 1 drive capacity. (4 1TB drives -> 2TB total storage.) can lose any 1 drive, and even a second drive if it's not the wrong one (the mirror of the first, 1/3 chance). (I personally have 2 machines with this and really is how I've had the same volume for 10 years now; I've replaced a drive twice in those 10 years I think.)

this is what i wanted to know.

For RAID 10, do all the drives have to be the same size?

Dmess85 posted...

For RAID 10, do all the drives have to be the same size?

it may depend on the RAID controller. when I started I was under the impression that all of the drives had to be the same model not just size, but that doesn't seem to be the case. reading, some sources say that even if they have different sizes, the smallest drive will determine the size of the volume.

something I'll point out is, it is a bit cumbersome to implement. you do actually end up with 4 drives and 4 power cables going to them, and 4 data cables, and if one of the 8 data cable ends comes lose you will lose a drive and have to figure out which port is which drive to fix it and then rebuild the RAID after. and annoyingly SATA cables don't attach very securely. (maybe modern ones are better than the ones I have.)

also, depending on the hardware you have, hard reboots will result in long rebuild operations. (supposedly one of the benefits of "hardware RAID controllers" is that they have batteries and prevent this issue. can use UPS instead to protect against power outages, but that's not the only kind of hard reboot.) (rebuild is basically 1-2 hours running in the background. your computer is slower for those 1-2 hours. for NAS maybe it wouldn't matter since it wouldn't be the PC you're using.)