5 ms·
If you read the paper you'll find this: > In our experiments, we observed five out of the six expected failure types, including bit corruption, shorn writes, u
by zerd 13y ago
If you read the paper you'll find this:
> In our experiments, we observed five out of the six expected failure types, including bit corruption, shorn writes, unserializ- able writes, metadata corruption, and dead device. Surprisingly, we found that 13 out of 15 devices exhibit failure behavior contrary to our expectation. This result suggests that our proposed testing framework is effective in exposing and capturing the various durability issues of SSDs under power faults.
Spinning hard drives fail too. All drives fail eventually.
- tbyehl 13y ago> Spinning hard drives fail too. Why hasn't this been a problem with the cache on spinning disks? Are they typically only buffering reads?
- rythie 13y agoI doubt any spinning disk buffer writes, it's risky and requires a battery to prevent corruption. However most enterprise RAID systems buffer writes so it could be happening there.
- rosser 13y agoActually, all (or almost all) spinning rust disks buffer writes, unless they're instructed not to, which is normally done by hardware RAID controllers. In that case, the HBA takes over the job of buffering writes, and can safely acknowledge them to the OS as flushed before the write ever actually touches disk, because the writes are stored in battery-backed or otherwise non-volatile memory. It's well known in communities that care about storage reliability (such as the database world, which is where my experience comes from) that consumer-grade drives, in particular, are notorious for lying about writes having been successfully flushed to the underlying media.
- blibble 13y agomodern disks use the rotational energy in the spindle to do a "death write" to a reserved area when power is lost.
- IgorPartola 13y agoGot a link? Sounds fascinating.