How many implementations of RAID can you put together

[Tcrumpen]

I know some people will just stick with say RAID 5 or i some cases (Like Linus did) they'll use RAID 1 and 0 together (RAID 10) I'm just wondering how many implementations of RAID can you put together like could you do RAID 5 and RAID 1 together (So you stripe the disks with parity and then make a carbon copy of it for extra redunadncy.

 

There is more a theoretical question rather than a "Realistically would you do this?" style of question

[leadeater]

You can do almost any combination of RAID levels together:

• 10
• 0 + 1 (yes that is actually different)
• 50 or 60
• 0 + 5 or 0 + 6 (if you're insane enough)
• 51 or 61
• 55 or 56 or 65 or 66 (if you're insane enough)
• 1 + 5 or 1 + 6 (if you're insane enough)

Hell with software RAID I think you can nest RAIDs more than two levels lol.

 

As for the actually common nested RAIDs those are 10, 50/60 and 51/61 with that last ones being the least common.

[Razor Blade]

During the LMG video about the Whonnock server failure Linus explained he had 3 controllers running raid 5 and those raid 5's were striped together in Windows. Up until about a month ago I had no idea what any of that even meant lol

[seagate_surfer]

One tool that could help conceptualize/visualize here is the Synology RAID Calculator on their support site. Ignore the SHR categories unless you're planning on getting a Synology box as those are proprietary. This helps visualize not only different RAIDs but total storage amounts with different disc amounts/capacities as well.

[straight_stewie]

There are the standard single level RAID types:
 

Spoiler

• RAID 0: block striping, no parity
• RAID 1: mirroring, no parity, no striping
• RAID 2: bit level striping with Hamming ECC
• RAID 3: byte level striping with dedicated parity 
• RAID 4: block level striping with dedicated parity
• RAID 5: block level striping, distribute parity
• RAID 6: block level striping, double distributed parity

Then there are standard nested RAID types

Spoiler

RAID 01: RAID 1 array of RAID 0 arrays

RAID 03,53: RAID 3 array of RAID 0 or RAID 5 arrays

RAID 10: RAID 0 array of RAID 1 arrays

RAID 50: RAID 0 array of RAID 5 arrays

RAID 60: RAID  0 array of RAID 6 arrays

RAID 100: RAID 0 array of RAID 0 arrays of RAID 1 arrays

Then you have various non standard RAID types, which I will not list here (most are proprietary anyway). Additionally, in two level nested RAIDS of only standard types you can have 42 possibilities (some may not be useful). In three level arrays you have 210 possibilities... Whatever... The pattern goes on and on like that.

Here are some useful wikipedia articles on the matter:

• Standard Single level RAID types: https://en.wikipedia.org/wiki/Standard_RAID_levels
• Standard nested RAID types: https://en.wikipedia.org/wiki/Nested_RAID_levels
• Common non Standard RAID types: https://en.wikipedia.org/wiki/Non-standard_RAID_levels