Me and my friend were discussing this the other day about how he said RAID is no longer needed. He said it was due to how big SSDs have gotten and that apparently you can replace sectors within them if a problem occurs which is why having an array is not needed.
I replied with the fact that arrays allow for redundancy that create a faster uptime if there are issues and drive needs to be replaced. And depending on what you are doing, that is more valuable than just doing the new thing. Especially because RAID allows redundancy that can replicate lost data if needed depending on the configuration.
What do you all think?
SSDs still have component bottlenecks that can kill the whole drive, same as hard drives.
Also, 3-2-1 is far superior to RAID, but having RAID on top of that is nice.
- Maintain three copies of your data: This includes the original data and at least two copies.
- Use two different types of media for storage: Store your data on two distinct forms of media to enhance redundancy.
- Keep at least one copy off-site: To ensure data safety, have one backup copy stored in an off-site location, separate from your primary data and on-site backups. https://www.veeam.com/blog/321-backup-rule.html
Unlike hdd, I never experienced graceful disk failures on ssd. Instead, they just randomly decided to die at the most inconvenient time. Raid 1 saved my hide a couple times now from those ssd failures.
Yep. While it has been decades since I had a home SSD failure. But I have had 2 SSD failures in the last 10 years in server hardware. In the first case it was RAID striped and I needed to restore from backup. In the second case it was part of a raid 1 array and I just requested a replacement and got on with my day.
In my house, I have non raid SSDs on my own PC. But important stuff is on my NAS made up of 4xHDD drives in raid 5 (that also has the important folders backed up to an encrypted cloud).
RAID still has a place in an overall data security solution. Especially for servers that you want to keep up.
its not about the individual drive… its about total drive failure… if that ssd’s controller dies it doesnt matter if it has extra data sectors.
that said, I moved on from raid by mirroring multiple , unraided NAS devices for redundancy with data stored specifically on the drives in such a way as to eliminate cross disk logical volumes.
you can replace sectors within them if a problem occurs
That won’t help you if sector where your data is located dies!
Its very much still needed and heavily utilised in the enterprise world. Volume size is usually the lowest priority when it comes to arrays, redundancy and IOPS (the amount of concurrent transactions to the storage) is typically the priority. The exception here would be backup and archive storage, where IOPS is less important and volume size is more important.
As far as replacing sectors goes, I’ve never heard of this and I might just be ignorant on the subject but as far as I know you can’t “replace” a bad sector. Only mark it as bad and not use it, and whatever was there before is gone. This has existed since HDD days. This is also why we use RAID - parity across disks to protect data.
Generally production storage will be in RAID-10, and backup/archive storage in RAID-6 or in some cases RAID-60 but I’m personally not a fan.
You also would consider how many disks are in the volume because there is a sweet spot. Too many disks = higher likelihood of total array failure due to simultaneous disk failures and more data loss in the event it does, but too few disks and you won’t have good redundancy, capacity or performance either (depending on RAID level).
The biggest change I see in RAID these days is moving away from hardware RAID cards and into software-based solutions like Microsoft Storage Spaces, md, ZFS and similar. These all have their own way of doing things and some can even synchronise the data with other hosts.
Hope this helps!
SSDs man, I personally still don’t trust them for primary storage. My data array is unraid, several spinning disks. Spinners just always work for me, there are gotchas of being jostled or turned off incorrectly, but if you treat them well they’ll last a real long time. Plus the double redundancy of my array and I’m very happy with it. (Plus I don’t see 20TB ssds on the market for 300 bucks either).
SSDs though wear out, they only have so many IOPS in them. I had some in a traditional raid and it just ate through them. Too many writes and I had 5/6 fail on me. I use them now as cache drives, for unraid you can set a faster drive to store data temporarily, and then it will move it off the cache drive later onto the main array, and that’s a level of risk I’m happy with.
He said it was due to how big SSDs have gotten and that apparently you can replace sectors within them if a problem occurs which is why having an array is not needed.
Buying SSDs with the same capacity as my NAS with 70TB (after raid 6) would cost almost tripple of what my setup (including the NAS) costs.
So unless you shit money, SSDs are not an option for anything with a decent capacity.
I don’t think the internal wear-leveling and overprovisioning of SSDs can or should be able to replace raid. Disregarding a dead sector without losing capacity is great, but it won’t help you when (for example) the controller dies.
Depending on the amount of data you’re storing SSDs also might be too expensive.
The only exception is maybe Raid 0 in a normal PC. Here it’s probably better to just get one disk for each logical drive.
