3 ms·
This is probably why people like BackBlaze use RAIN (Redundant Array of Inexpensive Nodes) instead of RAID. Also, their drive failure is 10 disks/day out of a
by ghshephard 12y ago
This is probably why people like BackBlaze use RAIN (Redundant Array of Inexpensive Nodes) instead of RAID.
Also, their drive failure is 10 disks/day out of a population of 44,100 drives, about 0.02%.
So, between the lack of correlation of failure (their Nodes, or, "Pods" are in different racks), their ability to lose an entire POD regardless (they have 3 parity pods), and the relatively low disk failure rate - the large drives aren't a problem. A rebuild in 2-3 days is more than fine.
- sitkack 12y agoThere is a very interesting engineering optimization strategy at play here, would love to do/see a blog post on it. Simple structures, with a large safety margin and simple control flow vs complex structures, very light weight but at the limits of capacity. Like an ethernet switch doesn't need complex flow routing algorithms when the raw backplane bandwidth is some multiplier higher than will ever experience contention. It always seems to me, that things built near their design limits will eventually expose a catastrophic flaw. Human engineered items that have stood the test of time, Roman Aqueducts, Brooklyn Bridge, DC3, Dodge Dart, Toyota Corolla, AK47, PDP8 all have commonalities in their design philosophies.