What is RAID

[ShayMaster [PC Noob]]

Across the PC community I've heard a term called "Raid" or "RAID0" can anyone explain to me whatever that is, you can also tweet me the answer @ShintakiShrooms

[Godlygamer23]

RAID stands for Redundant Array of Inexpensive(or Independent) Disks. It's a technically that allows you to combine drives in various ways, allowing some to be combined together for extra speed, or others being used strictly as mirrors for redundancy. 

[DarkRuskov]

more details here :

https://en.wikipedia.org/wiki/RAID#Standard_levels

[Stryder721]

Never use raid0, if a drive fails your data is gone

[DarkRuskov]

1 minute ago, Stryder721 said:

Never use raid0, if a drive fails your data is gone

yeah but if you use it for your system it will have a faster system and if a drive fails you just have to reinstall it, no big deal. Raid 0 is useful. I would correct "you shouldn't use raid 0 to store data" (even that depends on your setup and your needs).

[Djole123]

RAID, in a nutshell, means connecting multiple drives and working as one. Two most common types are RAID 0, which merges two drives in one (ie 2x 1TB will give you 2TB partition) and RAID 1 which clones one drive to another.

[Stryder721]

Me personally i dont use raid, so i'm not too experienced in this matter lol. but in every video i seen about raid they always told me that if a drive failed all data is lost. I tend to just install my os and have everything (downloads, music, pictures) just residing on another drive

[Oshino Shinobu]

RAID = Redundant Array of Inexpensive/Independent Drives (Originally Disks, but flash storage isn't a disk, so it technically doesn't cover them).

It's a technology that is used to combine multiple drives in various different ways. Here's an overview of the most common RAID types:

 

RAID 0 (technically not RAID) is a striping RAID. Data is striped evenly across the drives in the array. So if you have 2 drives in RAID 0, half of the data is written to drive 1 and the other half to drive 2. It improves speeds and increases storage capacity by combining drives. If you have two 200GB drives in RAID 0, you have 400GB effective storage, with (theoretically) double the speed. For working out the capacity of RAID 0, it's the number of drives * smallest drive size. 

 

Theoretically, there's no maximum for the number of drives you can have in RAID 0, but as you add more drives, the chances of data loss increases, as if you lose one drive in the array, all data is lost from the entire array (or more accurately, all data in the array is rendered useless. The data is still on the working drives, but it is incomplete). 

 

RAID 1 is a mirror RAID, which replicates all data across the drives in the array. This means that as long as one drive remains in the array, you still have all of your data. The array capacity is always the size of the smallest drive in the array, it doesn't combine like it does in RAID 0. Performance of RAID 1 stays around the same as the slowest drive in the array. There's no real maximum number of drives you can have in RAID 1.

 

RAID 10 is basically RAID 1 + 0. It combines RAID 1 arrays in RAID 0 to offer some redundancy with a performance increase. You can lose a maximum of 2 drives (one from each RAID 1 array, if we're assuming it's two RAID 1 arrays. If you use 3 RAID 1 arrays, you can lose a maximum of 3 drives). The capacity is 50% of the combined drives. 

 

RAID 5 is a little more complicated than the others. It uses striping, along with parity partitions that allows it to offer a mix of performance, capacity and redundancy. It requires a minimum of 3 drives to operate, but it is generally advised to use 4 or more drives. RAID 5 capacity is the combined total capacity of the drives (if we assume they're all the same size) minus 1 drive. Best way to explain RAID 5 is through images, really. 



RAID 6 is similar to RAID 5, but uses double parity. 

Linus has videos covering RAID levels. 
 

 

EDIT: There is also JBOD (Just a Bunch Of Drives) which is often grouped with RAID, but really, it's just combining multiple drives as a single volume. There's no striping, mirroring or parity partitions involved. It's pretty much just for combining storage capacity without additional redundancy.

[Oshino Shinobu]

25 minutes ago, DarkRuskov said:

yeah but if you use it for your system it will have a faster system and if a drive fails you just have to reinstall it, no big deal. Raid 0 is useful. I would correct "you shouldn't use raid 0 to store data" (even that depends on your setup and your needs).

RAID 0 for booting isn't really advisable. It's better to go for a single, faster drive. You have to wait for the controller and array to initialise before being able to load the OS with RAID, so it can actually slow boot times. 

[mikat]

28 minutes ago, Stryder721 said:

Never use raid0, if a drive fails your data is gone

*only use raid0 if you have a backup system

[Donut417]

28 minutes ago, DarkRuskov said:

yeah but if you use it for your system it will have a faster system and if a drive fails you just have to reinstall it, no big deal. Raid 0 is useful. I would correct "you shouldn't use raid 0 to store data" (even that depends on your setup and your needs).

That was very true before the availability of inexpensive SSD's. Now I would say Raid 0 is pretty much dead in most cases.  Now your better off just getting an SSD and calling it a day. Raid 1,5 and 6 are still useful in applications where you need data redundancy. 

 

[DarkRuskov]

56 minutes ago, Stryder721 said:

Me personally i dont use raid, so i'm not too experienced in this matter lol. but in every video i seen about raid they always told me that if a drive failed all data is lost. I tend to just install my os and have everything (downloads, music, pictures) just residing on another drive

actually some (if not most) raids can save your data, so you're confusing raid in general with raid 0

33 minutes ago, Oshino Shinobu said:

RAID 0 for booting isn't really advisable. It's better to go for a single, faster drive. You have to wait for the controller and array to initialise before being able to load the OS with RAID, so it can actually slow boot times. 

boot times maybe (although usually it is still faster) but not that much and two ssds in raid 0 are faster than one so sometimes it is not possible to buy a single faster drive.

31 minutes ago, mikat said:

*only use raid0 if you have a backup system

true dat

21 minutes ago, Donut417 said:

That was very true before the availability of inexpensive SSD's. Now I would say Raid 0 is pretty much dead in most cases.  Now your better off just getting an SSD and calling it a day. Raid 1,5 and 6 are still useful in applications where you need data redundancy. 

 

not really, as i said it still can speed up your ssd.

[Donut417]

1 minute ago, DarkRuskov said:

actually some (if not most) raids can save your data, so you're confusing raid in general with raid 0

boot times maybe (although usually it is still faster) but not that much and two ssds in raid 0 are faster than one so sometimes it is not possible to buy a single faster drive.

true dat

not really, as i said it still can speed up your ssd.

Im pretty sure Linus even stated it might speed it up a bit, but its not worth it performance wise. Keep in mind he had like 9 drives in a Raid 0 config. Truthfully I dont think the reward out weighs the risk. Especially since PCIe Solutions are out in the wild now and can give great performance. The most users would be fine with a single drive solution. 

[DarkRuskov]

2 minutes ago, Donut417 said:

Im pretty sure Linus even stated it might speed it up a bit, but its not worth it performance wise. Keep in mind he had like 9 drives in a Raid 0 config. Truthfully I dont think the reward out weighs the risk. Especially since PCIe Solutions are out in the wild now and can give great performance. The most users would be fine with a single drive solution. 

on ncix they said that it might be worth the extra buck  and pcie SSDs are much more expensive plus you need to have a compatible motherboard it you go with m.2 .

[CtrlAltELITE]

1 hour ago, Oshino Shinobu said:

RAID 0 for booting isn't really advisable. It's better to go for a single, faster drive. You have to wait for the controller and array to initialise before being able to load the OS with RAID, so it can actually slow boot times. 

I disagree. Windows installs are quick, especially on a raid 0 array of SSDs. If a drive fails its not the end of the world and the boot speeds and extra snapyness are well worth it, I run 2x 128gb samsung 840s in 0 for boot and some games, all my important files are backed up on the 1TB HDD, and my NAS, and a seperate "safety partition" on the boot SSD of the NAS, and a offsite 1TB HDD in storage for monthly-ish backups.

 

Using it as your primary storage medium is extremely dumb though I do agree. (there was a post on here not so long ago with someone who had used 4-5x 1tb HDDs in zero as their sole storage for "extra speed".

[Oshino Shinobu]

2 minutes ago, CtrlAltELITE said:

I disagree. Windows installs are quick, especially on a raid 0 array of SSDs. If a drive fails its not the end of the world and the boot speeds and extra snapyness are well worth it, I run 2x 128gb samsung 840s in 0 for boot and some games, all my important files are backed up on the 1TB HDD, and my NAS, and a seperate "safety partition" on the boot SSD of the NAS, and a offsite 1TB HDD in storage for monthly-ish backups.

 

Using it as your primary storage medium is extremely dumb though I do agree. (there was a post on here not so long ago with someone who had used 4-5x 1tb HDDs in zero as their sole storage for "extra speed".

To be clear, I have my OS on 2x 250GB 840 EVOs in RAID 0, but I don't recommend it. 

It's certainly not the end of the world if a drive dies, but it's worse than just losing a scratch disk that's in RAID 0. The difference in boot times between a single 500GB 840 EVO and my RAID 0 setup is negligible. I just have a RAID 0 setup because I wanted to have 3 SSDs in my system so they can be displayed. 

[agent_x007]

I use RAID0 daily and I can tell U that it's fun to have, but U need that backup drive to save data U can't lose (I use 2x1TB in RAID0 and 2TB + 4TB non-RAID, as main storage/backup).

How many times I lost RAID0 non-backed up data :
Once
Reason : Memory oveclocking combined with BCLK OC corrupted MBR data on RAID drives.

How many years I was using RAID0 without problems ?
From 2007 (2x 640GB WD AAKS was my first setup) to I think 2013 (when my data loss happened), so 6Y in total without problems (I managed to exchange drives in array two times by that point).

Also : HDD's I used NEVER broke while being in RAID0.
So far I used 2x WD 640GB AAKS (first RAID setup), then 2x Samsung 500GB (second), and now I'm using 2x 1TB WD EZEX (third setup).
The only drive that failed so far was Samsung F3 HD502HJ about 2 years after I switched RAID0 drives to EZEX's (other F3 still "lives" ).
And even that was only a electronic failure (platters and motor are 100% OK, I switched electronic from other drive I had to see if it works - and it did/does).

Where U can use RAID0 :
RAID0 is excellent temporary buffer for large data.
It's usefull with transfering and storing [temporary or not], large files (1GB+).
My current RAID0 setup can sustain on avg. 250MB/s transfer speeds (read/write) from/to my SSD (340MB/s is max. and 160MB/s is min.).
Also : It can be useul in NAS if U don't have money to buy larger capacity SSD for shared storage, but U still need the 100MB/s+ sustained transer speeds to maxed out 1Gbit/s LAN.

[vorticalbox]

1 hour ago, Stryder721 said:

Me personally i dont use raid, so i'm not too experienced in this matter lol. but in every video i seen about raid they always told me that if a drive failed all data is lost. I tend to just install my os and have everything (downloads, music, pictures) just residing on another drive

raid 0 will stripe the data half to one drive half to another this has the benefit so increasing performance and giving access to all the storage, if a drive fails data is lost.

 

Raid 1 will store the data on one drive and mirror it to the other effectively reducing your total storage by half but comes with the benefit of if a drive fails all the data can be copied back to a new drive.