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Why is the IT industry so cautious about SSD reliability? We have spent decades developing HDD fault-tolerance mechanisms or processes such as RAID and backups.

by mrb 15y ago

Why is the IT industry so cautious about SSD reliability? We have spent decades developing HDD fault-tolerance mechanisms or processes such as RAID and backups. We should trust them.

viraptor 15y ago
We're currently trusting a drive that might fail in 5 or so years in one specific place. The rest is recoverable, the place of failure might be overwritten anyways, the data might not be needed, smart will warn you that the problem is close in many cases... With SSD you have a chance of going completely blank. If it happens to be a firmware issue on a RAID mirror, there's also a chance of common fault in both drives. Even if you have backups in that case, do you really want to deal with such situation?
- rbanffy 15y ago
  > smart will warn you that the problem is close in many cases... According to Google, about two thirds of the time, SMART will warn you. > there's also a chance of common fault in both drives. Never, ever trust a RAID array made from identical disks. Whenever possible use different manufacturers, different models and different batches. Whatever caused failure of one drive will eventually cause the failure of its twins. If all twins are in the same array, you won't be happy.
Artagra 15y ago
Because even if you have rock solid RAID and backup solutions (and unfortunately, many, many companies don't), there is a cost involved in replacing drives. Especially when you are talking about an end user. Yes, most servers have RAID and you can do a swap out with no down time, and at minimal cost. But if you have an SSD failing in a users laptop / desktop, the down time and frustration involved can be major.
r00fus 15y ago
RAID doesn't play well with TRIM from most SSD chipsets... it's not a panacea. As SSDs are maturing it looks like there are two distinct markets where hard-disks can't go: 1) In servers, vendors offer cards that tie directly into the PCIe bus, bypassing SATA ( 2) For laptops, one can look at the Macbook Air and it's SSD chips. Right now they are connected via SATA, but if that becomes a limiting factor, I see how that would be bypassed as well. For now HDs and SSDs are very similar, but SSDs (which are essentially flash memory) can and will go where HDs cannot. They are quite different.

by mrb 15y ago

Why is the IT industry so cautious about SSD reliability? We have spent decades developing HDD fault-tolerance mechanisms or processes such as RAID and backups. We should trust them.

viraptor 15y ago

We're currently trusting a drive that might fail in 5 or so years in one specific place. The rest is recoverable, the place of failure might be overwritten anyways, the data might not be needed, smart will warn you that the problem is close in many cases... With SSD you have a chance of going completely blank. If it happens to be a firmware issue on a RAID mirror, there's also a chance of common fault in both drives. Even if you have backups in that case, do you really want to deal with such situation?

rbanffy 15y ago
> smart will warn you that the problem is close in many cases... According to Google, about two thirds of the time, SMART will warn you. > there's also a chance of common fault in both drives. Never, ever trust a RAID array made from identical disks. Whenever possible use different manufacturers, different models and different batches. Whatever caused failure of one drive will eventually cause the failure of its twins. If all twins are in the same array, you won't be happy.

Artagra 15y ago

Because even if you have rock solid RAID and backup solutions (and unfortunately, many, many companies don't), there is a cost involved in replacing drives. Especially when you are talking about an end user. Yes, most servers have RAID and you can do a swap out with no down time, and at minimal cost. But if you have an SSD failing in a users laptop / desktop, the down time and frustration involved can be major.

r00fus 15y ago

RAID doesn't play well with TRIM from most SSD chipsets... it's not a panacea. As SSDs are maturing it looks like there are two distinct markets where hard-disks can't go: 1) In servers, vendors offer cards that tie directly into the PCIe bus, bypassing SATA ( 2) For laptops, one can look at the Macbook Air and it's SSD chips. Right now they are connected via SATA, but if that becomes a limiting factor, I see how that would be bypassed as well. For now HDs and SSDs are very similar, but SSDs (which are essentially flash memory) can and will go where HDs cannot. They are quite different.