Common oversights with SSD specifications
It is commonly assumed that solid state disks are more reliable than hard disks because they have no moving parts. While the evidence for this is lacking, we’ll look at the impact of non-recoverable read errors on reliability. Continue reading
I have seen failure analysis reports on many hard disk programs over the years. Typically, mechanical related failures account for less than half the total. Electronic and microcode failures are quite common (ever had a cell phone break?). So, the non-mechanical argument needs to be backed up with field data.
In this series, we are considering the use of SSDs in storage systems. Thus, we need to consider reliability at the system level. In most storage systems, the storage devices are configured in a RAID (Redundant Array of Independent Disks). This allows the system to preserve data in the presence of failures. Continue reading
The other contributor to reliability
It seems to be rather common to focus on complete device failure as a major contributor to reliability. The impact of non-recoverable read errors (NRRE) tend to be unappreciated in this regard, since it depends on the system architecture. Continue reading