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How do "surveillance" drives fit into that? They're supposed to be special for being reliable with a lot of writing, several orders or magnitude more the drive'
by lopmotr 7y ago
How do "surveillance" drives fit into that? They're supposed to be special for being reliable with a lot of writing, several orders or magnitude more the drive's capacity. Apparently normal hard drives aren't reliable enough for recording CCTV footage.
- dragontamer 7y agoAll hard drives have effectively infinite rewrite capability, unlike SSDs. I know I've seen surveillance drives before (WD Purple), but I never figured out what made them special compared to others. Looking at the WD Purple drive marketing material... they describe "support for 64 cameras". Which means the CCTV community is willing to pay for write bandwidth. It'd probably be a standard 7200 PMR drive, but with assurances and maybe some tests on the write performance.
- wtallis 7y agoI've heard WD allude to their surveillance drives having some kind of firmware optimizations to handle multiple streams of writes with good QoS. It seems plausible they they would have a bit of a different write caching strategy based on minimizing seeks and trusting that the data coming into the drive is interleaved from multiple sequential write streams even though at any given moment the command queue will look like a bunch of random writes.