RAID terminology question

[Lightning]

I am confused about the different RAID types

Is hardware RAID is often referred to RAID modes like RAID 0, RAID 1 and RAID 5 that you see on motherboards?

So then what is software RAID (unRAID etc.)? Do they use RAID 0, 1, and 5 also or are they a completely different thing? I just watched a guide on unRAID and you just add drives and not have to hard set RAID modes like you do with hardware RAID.

 

I am planning to build a cheap NAS server.

[themctipers]

hardware raid is more detail over just saying raid

raid 0/1/5/10 is for specifying the raid method (for example 0 is just striping data)

you can use raid from software (windows, unraid, even bios) or hardware (physical raid card)

[Lurick]

Software and hardware RAID is where the RAID itself is built.

In a hardware raid you have a dedicated controller and in software RAID you do it on the OS or other software programs.

In hardware if you lose the hardware then your raid is usually gone but in software raid you'll lose it if you delete the software that makes the raid and holds the info.

 

They have the same type of modes.

[Lightning]

Can you set unRAID to automatically do a raid 5? I just saw a video on unraid and the person basically added a bunch of unrelated drives into the array and it worked. I thought RAID setups require same hardware.

 

To me, it seems like unRAID doesn't use the traditional RAID modes I am familiar with and it is a whole separate entity itself.

[leadeater]

1 hour ago, Lightning said:

Can you set unRAID to automatically do a raid 5? I just saw a video on unraid and the person basically added a bunch of unrelated drives into the array and it worked. I thought RAID setups require same hardware.

 

To me, it seems like unRAID doesn't use the traditional RAID modes I am familiar with and it is a whole separate entity itself.

unRAID is not using traditional RAID, it uses a dedicated parity disk which is most like RAID 4 but it is not RAID 4.

 

Traditional RAID is quite happy to use different disks and sized disks however all disks in an array are treated as the same size as the smallest disk. If you want to add a disk to an existing array it must be the same size or bigger than the smallest current disk.