I am planning to use Windows Storage Spaces to create a 2-way mirror volume (i.e. Software RAID-1) out of 2 NVMe SSDs, with the most important factor being reliability and data redundancy (performance is not much of a concern).
So what is the best way to have a reliable (as in data loss protection) software mirror raid 1 configuration made out of 2 NVMe SSDs? In particular:
- Would using 2 different SSD brands or models (of equivalent capacity) be prudent to minimize the risk of both failing at or near the same time (as may often be the case especially if the 2 drives are coming from the same batch)?
- Would using one DRAM-less SSD (one with Host Memory Buffer HMB feature) and one with DRAM cache have some kind of negative consequences, especially in regard to sudden power loss (so that both drives remain in-sync even in such scenarios)? And is it then prudent to completely disable write caching on those drive?
- Other than a performance hit, if the 2 SSDs operate at somewhat different speeds, are there any negative reliability consequences for a software mirror raid?
- Given these are SSDs, does it make sense to create a storage space (volume) say ~20% smaller than the drive's capacity, so that there is enough free space to improve reliability?
- Windows Storage Spaces in particular: does TRIM still work properly in case of using SSDs for a fully-provisioned 2-way mirror storage space?
Given these are SSDs, does it make sense to create a storage space (volume) say ~20% smaller than the drive's capacity, so that there is enough free space to improve reliability?No, it does not. I haven't seen hardware that unreliable. If I had, I wouldn't use it. Losing 20% of the total capacity of the storage solution is ridiculous.