6 ms·
Will we hit a point where the size of the drive is simply too big to get the data off in any decent amount of time?
by post_break 8y ago
Will we hit a point where the size of the drive is simply too big to get the data off in any decent amount of time?
- androidgirl 8y agoTape is already like that.
- a012 8y agoAFAIK new generation of tape has decent read-write speeds.
- astrodust 8y agoDecent for tape, or decent in general?
- gamegoblin 8y agoTape sequential throughput is higher than HDD. It's the latency/seek time that gets you. But for a recovery scenario, you can hopefully just do a giant sequential scan.
- astrodust 8y agoObviously. I mean more like what's the recovery time from tape vs. cheap HDD array?
- ahoka 8y agoIf I did my calculation right it takes more than 16 hours to retrieve all 15T from the driver. Wow!
- a2tech 8y agoI have a lot of places already where recovering from a full wipe is almost not worth it. Customers with 100's of TB of data in 'prosumer' NAS devices that are chock full of regular drives.
- deleted 8y ago[deleted]
- stephengillie 8y agoThis is one reason why RAID 0+1 is a best practice, and RAID 5 & 6 are no longer recommended. It takes too long to rebuild the array, leading to a multi-failed disk situation.
- chrisper 8y agoRaid 01 has its own risk. If the wrong two disks fail your entire array is toast
- nine_k 8y agoYou can upgrade a 2-disk RAID1 to a 3-disk RAID5, then chain them to RAID0 as normal. It gives you a better chance to keep data intact, hopefully without lowering the write speed seriously. https://en.wikipedia.org/wiki/Nested_RAID_levels#RAID_50_(RAID_5+0) https://en.wikipedia.org/wiki/Nested_RAID_levels#RAID_50_(RA...
- zaarn 8y agoRAID 50 doesn't really solve it, it exposes you to some more risk since you can still die with 2 disks but now you have more disks in each sub array. The correct answer is either a 3-mirror RAID1 or RAID6. Bcachefs also promises some solution to this by allowing both erasure encoding and replication to co-exist, according to it's documentation.
- throwaway2048 8y agoas opposed to raid 5 where if any two disks fail your array is toast, raid 6 increases this to 3. However both raid 5 and 6 have 2 huge problems: Data inflight at write time (power/hardware failures are more likely to corrupt the array, especially silently, which is the worst outcome). Parity calculations require you to spin up the whole raid5/6 array during a rebuild, massively increasing the chance of a multi drive failure and a lost array. If one close-to-EOL drive dies, putting its sister drives through what is essentially an all day full tilt stress test is a terrible, terrible idea, and this idea keeps getting worse (takes longer) as drive sizes grow. raid 0+1 sidesteps these issues mostly at a modest increase in drive count, its a no brainier for most setups.