How to remember RAID levels?

Question

How do you remember(if you really do :-)) all the different levels and what each level does? Can anyone suggest an easy way to remember?

Answer 1

Remember it like this:

Answer 2

0 - S (stripe)

1 - M (mirror)

5 - P (parity)

10 - MS (mirror + stripe)

Smart Men Pay MicroSoft

or

Silly Men Pay MicroSoft

Answer 3

I remember them in order by the number of punches in the face a failure of any particular level equates to:

RAID 6 - six punches in the face when it fails, because you had two dang parity drives and thought you were really uber safe....until your Adaptec controller said "no arrays detected".

RAID 5 - five punches in the face when it fails, especially when your Adaptec controller says "no arrays detected"....or a second drive fails during a rebuild.

RAID 1 - one punch in the face, especially if you were using a hardware controller and thought you could just take a drive out and grab the data easily...because, hey, it's just a mirror, right?

RAID 0 - zero punches in the face, because you were expecting it and had full backups.

P.S. I do not work for Adaptec.

Answer 4

0 = No Redundancy

1 = 100% = 100% Redundancy

10 = 1 and 0 together

5 = halfway in-between 0 and 10 (0 uses 4/4 disks, 10 uses 2/4 disks, 5 uses 3/4 disks)

6 = like 5, plus 1 extra disk needed (e. g. 3/5 disks)

Answer 5

You learn terms you use daily. 0, 1 and 5 become natural, 6 is just 5 with an extra disk. I've never come across 2,3 or 4.

Answer 6

Well...

• RAID 0 is not RAID, it's just AID. That's easy enough.
• RAID 1 is mirroring. There's one mirrored copy of your data.
• RAID 2 and 3 are byte-level things that are extremely rare and you don't have to worry about or remember
• RAID 4 is rare; nearly the same category as RAID 2 and 3
• RAID 5 can work with five disks. Or only 3... 1 and 10 always need an even number of drives
• RAID 6 is RAID 5 with one more disk for parity
• RAID 10 is really raid 1+0, or sometimes 0+1 (those are opposites but many vendors get it backwards). All the two-digit RAID levels are easy, since they're literally just the other two numbers added together.

Answer 7

RAID 0 - Best performance, poor availability, only suitable for temporary files

RAID 10 - Good performance for twice the price, quick expansions, rebuilds are straight disk-disk copies

RAID 5+ - Cheap, poor performance for small random writes (4x), 10+ hour expansions, risky rebuilds, not suitable for hypervisors

Answer 8

From a security aspect:

• Raid 0 -> Striping because 0 means No backup if a disk fail
• Raid 1 -> Mirroring because 1 means a backup if a disk fail

0 -> Bad for security, 1 -> Good for security

Usually people only have problems to remember what 0 do and what 1 do.
You also have to remember 5 and may be 6 which is "5 + one(1) more parity information"

Answer 9

4 = like 5, but -1 point for possible hot spot problem

3 = like 5, but -2 points for seeking like a single drive

Answer 10

People seem to mostly confuse 0 and 1, but it's pretty easy to remember that RAID 0 provides zero help when you lose a disk.

RAID 10 is really RAID 1+0 (simple math! ;-)

RAID 2 to 4 aren't really worth remembering although RAID 4 is what NetApp uses.

Everyone seems to know RAID 5, so you just need to remember that RAID 6 is an extra parity drive. (RAID 6 doesn't really exist, BTW, it's also sometimes called RAID-DP for Dual Parity)

Answer 11

There is no easy way to remember it. One method i can suggest is as below Raid 0(zero means nothing) so no raid: raid with striping and no redundancy Raid 1(is the first level): so mirroring Raid 5: is striping for fast access and parity for redundancy Raid 6: striping plus double parity Raid 10: raid 1 group in striping http://www.slashroot.in/raid-levels-raid0-raid1-raid10-raid5-raid6-complete-tutorial

Answer 12

I like the way: "it is what you get when your disk fails".

RAID 1 = all

RAID 0 = nothing