5 ms·
How about the stupid idea of making a minimum block size be a multiple of the number of platters to write to. The block is divided evenly amongst all platters
by mahyarm 10y ago
How about the stupid idea of making a minimum block size be a multiple of the number of platters to write to. The block is divided evenly amongst all platters and are always at the same parallel track/sector. That way you can multiply the read/write speeds to be a function of the number of platters.
Instead of 50-100MB/s, you can get 4-8x the speed in large linear transfers, which helps get dead racks back up faster and would work quite well in backblaze's backup model.
Your block sizes will be huge, but I think in backblaze's case that doesn't really matter so much.
- eye2sky 10y agoYou cannot read from multiple platters in parallel. When you are aligned to read from a certain track on a certain side of a platter, you are not necessarily aligned on all platters. This head mechanism is not accurate enough for that.
- deleted 10y ago[deleted]
- rzzzt 10y agoGoogle's paper on datacenter hard drives addresses this point -- it's easier to do this and other tricks with a set of disks than attempting it within the confines of a single drive. https://news.ycombinator.com/item?id=11172876 https://news.ycombinator.com/item?id=11172876