Is RAID still relevant today?

[lingyi]

A current thread about the issues a poster is having with a RAID 0 setup has got me wondering, is RAID still relevant today for non-professional use?

RAID was developed when hard drives were small (capacity), slow and expensive, and certain applications exceeded the speed or storage capabilities of those drives. However, the limitations of the past have largely been overcome with large HDDs and fast SSDs. Even the combination of large, fast and cheap is a reality with 2tb SSDs available for <$300.

In theory RAID 5 and Raid 6 offer some level of backup protection*, but it's not a true backup solution which requires at least one complete copy of the data on separate HDDs, optical discs, tape or cloud.


*Edit: I believe data protection is a more accurate description

[lordsmurf]

is RAID still relevant today for non-professional use?
RAID was developed when hard drives were small (capacity), slow and expensive, and certain applications exceeded the speed or storage capabilities of those drives.

Nope. And for the reasons you stated. Even for professional needs, RAID has fallen out of favor.

RAID is now mostly for higher-end servers and SAN/NAS, for multiple access read/write. (Or gamers/goobers that don't actually understand how it all works. I see some really dumb stuff done, like RAID on SSD for home gaming desktops.)

RAID is not, and never has been, a backup method. RAID arrays can fail just as much as single drives, if not more.

RAID-0 (not actually a RAID, as R = redundant, and 0 is not redundant), and JBOD, have always been really stupid to use. RAID-0 was always abusive to disks, and would often fail faster than just using the drives individually. In the early 2000s, used on capture systems (not mine), failure was common. At one point, rarely a week passed that I didn't see "wah, my RAID failed" posts at one of several sites. As more have moved away from RAID, using purely SATA, those postings ceased. And "wah, my single drive failed" didn't fill the void left by it. This was a topic that I often felt like a broken record, constantly repeating myself in those earlier days. At the time, do RAID-1 or do something else (SCSI, better motherboard, etc). The RAID-1 write was like 75% of the RAID-0, not a huge deal, seeing as both were faster than the single IDE drives, maybe SATA-1.

Drive speed was also more about the drive itself, the motherboards drivers/chipsets, etc, not the array (or lack of array). RAID software/hardware vendor/drivers made a difference as well. It was just "RAID and done".

SATA, then SSD, has really tanked any need whatsoever for RAID. You are correct.

[JVRaines]

RAID was never intended for backup. It was a solution for speed (now superseded by solid state drives) and availability. Cloud server technology has overtaken RAID on the availability issue.

[KarMa]

If you want to get high write and read speed along with lots of cheap storage, you go with HDDs in RAID (usually RAID 0). With RAID 0 you can record at high data rates, like uncompressed 1080p/4K footage or RAW sensor data. RAID 0 is very risky in that 1 failed drive kills the entire array, so you obviously never want to keep anything on it for long. RAID 5 and 6 come with speed penalties with the creation of redundancy so they are better at protecting data than reading/writing.

There seems to be a move away from RAID to unRAID. It offers some level of data protection were one HDD is dedicated to redundancy, and the rest operate like their own drive. While unRAID can support as many drives as you want to throw at it, it only allows for the restoration of one data drive. So if you have an array of 20 data HDDs and 2 fail at the same time, then the data on the 2 drives are gone forever. But the 18 other drives will operate just fine as they were never striped together and acted like normal drives all along by storing complete files on one drive. If the stand alone parity drive fails, then you just lose the parity but the data HDDs will still be fine but not protected anymore. Since unRAID only writes one file to one drive, there is not always a speed advantage over a normal drive but is used more to help to reduce the risk of data loss among a group of drives without the risks associated with RAID 5 and 6 (risks of losing the entire array). An SSD can be added to the unRAID as a cache to speed up transfers.

It was a solution for speed (now superseded by solid state drives) and availability.

RAID 0 can still out perform a single SSD, it's just a matter if the added speed is needed/worth it.

The RAID-1 write was like 75% of the RAID-0, not a huge deal, seeing as both were faster than the single IDE drives, maybe SATA-1.

In RAID 1, the write is as fast as the write speed of the slowest drive. The RAID 1 read speed however uses all the drives at one time to greatly improve seek time and read rates over RAID 0.


Edit: Changed the word RAIDed to Striped.

[johnmeyer]

For writing uncompressed video in real time, I would think RAID would still be needed. However, most people in this forum (including me) are not dealing with uncompressed.

Writing 4K in real time, even uncompressed, might stress an SSD or non-RAID.

[Cornucopia]

Agree. If you deal with 1080p60 uncompressed, or stereoscopic FHD lossless, or RAW/HDR source footage, or 4k lossless/virtually lossless, or any 8k or above footage, or HFR (120fps or above), you may need RAID HDDs or SSDs, but that's it.

If you do go that route, I recommend either RAID 6, or RAID 10, but not RAID 0 alone, as that most assuredly is risky.
Or try ZFS.
But again, none of those are substitutes for proper backup.

Scott

[lingyi]

RAID was never intended for backup. It was a solution for speed (now superseded by solid state drives) and availability. Cloud server technology has overtaken RAID on the availability issue.

While I agree 100% that RAID (in any configuration) doesn't qualify as backup today, as I recall, RAID 1 (mirror raid) was touted as instantaneous backup at a time when the only external drives required SCSI (in its various incarnations), IDE connections on non-server motherboards were limited to four, and transferring GB's of data from drive to drive would take hours, possibly days, while slowing other processes to a crawl.

[koberulz]

What sort of speed would you get from an external USB3 SSD? I'm aiming to capture lossless 1080i50, ideally.

[jagabo]

Reports I've seen indicate around 400 MB/s for sustained reads and writes with USB3 SSD drives. You will get higher CPU usage with USB3 though. That could be a problem.

[koberulz]

I did successfully complete a Ut HD capture through VDub back when my RAID0 was still working, on an inferior machine to what I'm currently using. So I should be okay on that front, hopefully.

I'm not sure what sort of speed I need though.

[jagabo]

Hard drives max out at about 200 MB/s. Since you were using two hard drives in RAID0 the most you could have gotten was around 400 MB/s.

[koberulz]

2tb SSDs available for <$300.

[citation needed]

I'm seeing half the storage for twice the price compared to that, which makes me skeptical such a drive would be any good even if it does exist.

[jagabo]

Here's an example:

https://www.amazon.com/Micron-MTFDDAK2T0TBN-1AR1ZABYY-Solid-State-Drive/dp/B01LB05TOO/

And a little more:

https://www.amazon.com/SanDisk-Ultra-Solid-State-SDSSDH3-2TOO-G25/dp/B071KGS72Q/
https://www.amazon.com/Samsung-Inch-Internal-MZ-76E2T0B-AM/dp/B0786QNSBD/

[koberulz]

...d'oh. I've been looking at externals, which seem to be vastly more expensive. Didn't occur to me that the internals would be significantly cheaper.

[KarMa]

2tb SSDs available for <$300.

[citation needed]

I'm seeing half the storage for twice the price compared to that, which makes me skeptical such a drive would be any good even if it does exist.

For a SSD from Samsung, WD, or Sandisk you are looking at <$400 USD for 2TB. In Australia you are going to be paying higher import taxes so I can only imagine $600 AUD or higher (.72 USD = 1 AUD).

[koberulz]

Yeah looking at internal drives $630 seems to be the cheapest 2TB option for a WD Blue 3D.

Externally I was looking at Samsung T5 which came in at over a grand.