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.

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.

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 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!

…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!

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.

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.