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?
Yeah and Titanic was unsinkable.
If the controller in your SSD fries, it doesn’t matter how many unused gigabytes your SSD has got for relocating bad sectors. It is still fried. For you, that data is forever gone.
This is why you have redundancy. Full redundancy. You can go for RAID1, one disk die and you still have no data loss, or go bananas with RAID6, two full disks can die and you’re still going strong.
Ps. Spinning harddrives have had hidden sectors used for relocation of bad sectors for ages. It’s nothing new. If you have to much time on your hand, Google harddrive hidden sectors nsa.
…absolutely, positively, super false. I work in a sector where we’re constantly dealing with huge capacity enterprise SSDs - 15 and 30 terabytes at times. Always using RAID. It’s not even a question. Not only can you have controller malfunctions, but even though you’ve got what’s known as “over provisioning” on the SSDs, you still need to watch out for total disk failures!
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.
Reminds me of the days that cdroms were brand new and advertised like indestructible, with photos of elephants walking over it. Having said that I assume SSD disks can break like other hard disks can break, and in that case RAID can save a lot of time to get a computer back up especially when a lot of data is involved.
Had a microsd card literally break in half last week. They’re definitely not invincible
Yeah they sometimes get touted as that
Was that a SteamDeck? 🙃
3ds
Ok. Coz it is really common for SteamD users to forget removing SD card when didassembling device. Lots of cards have been lost
Actually that’s kinda what happened. I inserted the card to test if it was working before I put the bottom back on, but forgot to take it out. When I started screwing the bottom back on I heard a snap and that’s when I realized…
Definitely a lot of data lost, but most of it is redownloadable.
Funny. Growing up, I was taught to be extra careful with CDs because the moment you look at them wrong, all your data gets corrupted.
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
This is a total load of bullshit, your friend is wrong
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!
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.
RAID0 has always been playing with fire
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!
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.
Ssds maintain stats on cell writes and move data when a cell nears it end. They keep spare capacity hidden from end users for this. Not using part of the drive increases also this spare capacity.
However ssds do fail and moving data to spare cells doesn’t change that.
- Bit rot is still a problem, you need a high integrity file system and or RAID to avoid that
- Full drive failure is still about as likely, IE the main reason for RAID of multiple drives in the first place.
A good read on the problems with SSDs SSD 101: How Reliable are SSDs?
I found this article from the one you posted. It is crazy think DNA can be used for storage one day.
Higher end Samsung ssds were dying a lot faster than they should. I dont know what drugs your friend is on thinking they cant fail but theyd better have enough for the rest of the class.
This has nothing to do with ssd or their size. Harddisks also have a little spare area (though not as big) and can mark and remap failing sectors.
RAID (1) is still (possibly) good for the only thing it ever was (possibly) good for: Keeping the system running long enough for you to put in a new harddisk if one fails.
Think of industrial systems where every minute of downtime can cost thousands of dollars. And even there the usefulness of RAID can be questioned: should you not in that case have a whole spare system, easy to swap in, because more than just storage can fail?
And what about the RAID controller itself? Does it not add complexity and another point of failure to the whole system?
And most importantly: will anyone actually get notified of a failing disk and replace it quickly? Or will the whole thing just prolong the inevitable?
Would you even trust a system that had one disk fail already to keep going in a critical place? Or would it not be safer to just replace the whole thing anyway after one failure?
And what about the RAID controller itself? Does it not add complexity and another point of failure to the whole system?
This is why people prefers software raid these days instead of hardware raid.
That does not address the point made. It doesn’t matter whether it’s a complex hardware or software component in the stack; they will both fail.
Yes, I didn’t address the point made, just want to mention that people are increasingly avoiding hardware raid these days.
due to how big SSDs have gotten and that apparently you can replace sectors within them if a problem occurs
True, but that’s something an SSD does internally and is just there to prolong the lifespan.
You definitely still want a raid if you want to keep a system running during a disk failure. No amount of extra sectors and wear leveling will safe you from that
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.
