ATA Secure Erase is part of the ATA ANSI specification and when implemented correctly, wipes the entire contents of a drive at the hardware level instead of through software tools. Software tools over-write data on hard drives and SSDs, often through multiple passes; the problem with SSDs is that such software over-writing tools cannot access … Read more
When suddenly losing power, MLC/TLC/QLC SSDs have two failure modes: they lose the in-flight and in-DRAM-only writes; they can corrupt any data-at-rest stored in the lower page of the NAND cell being programmed. The first failure condition is obvious: without power protection, any data which are not on stable storage (ie: NAND itself) but on … Read more
Your reasoning is correct, though you’re missing the scale of the problem. Enterprise SSDs are being made with higher endurance MLC cells, and can tolerate very high write-rates. SLC still blows high-endurance MLC out of the water, but in most cases the lifetime write-endurance of HE-MLC exceed the expected operational lifetime of a SSD. These … Read more
Look for an industrial or ruggedized SSD for this application. A good example of a proper product spec. http://www.pretec.com/products/ssd-series/item/sata-ssd-series/a5000-industrial-grade ．Standard 2.5″ SATA III SSD, compatible with SATA III/II/I interface ．Capacity: 32GB ~ 256GB ．Data transfer rate: Up to 490 MB/s ．Built-in ECC (Error Correction Code) function ．Support ATA-8 command and SMART function ．Temperature I. Operating … Read more
Short answer, since I don’t see what problem you’re looking to solve… If you can, use separate devices. This depends on the scale of your environment… If it’s just a simple home system or a virtualized or an all-in-one ZFS solution, you can use a single device. In larger or high-performance ZFS solutions, I use … Read more
Drive manufacturers specify the reliability of their products in terms of two related metrics: the annualized failure rate (AFR), which is the percentage of disk drives in a population that fail in a test scaled to a per year estimation; and the mean time to failure (MTTF). The AFR of a new product is typically … Read more
This is true, and it was one of the key motivation to backing the switch from SLC (fast and durable flash cells, but small capacity) to MLC (slower and less durable flash cells, but bigger capacity). To give you some ballpark numbers (on old 34nm tech): SLC drive: 100K P/E cycles (program-erase cycles), 100 GB … Read more