HGST gets closer to shipping 10TB HDD
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Re: HGST gets closer to shipping 10TB HDD
#2Wow, hard drives are getting complicated!
You have to write 256MB to change a single bit?
And you have various zones, and you have to keep track of where data is written, because it's not written in order, and can be on any zone?
You would need some sort of battery backed scratch/cache area to pull this off, so that you don't have to write very often, otherwise I can't imagine performance will be very good.
Re: HGST gets closer to shipping 10TB HDD
#3Wow, hard drives are getting complicated! You have to write 256MB to change a single bit? And you have various zones, and you have to keep track of where data is written, because it's not written in order, and can be on any zone? You would need some sort of battery backed scratch/cache area to pull this off, so that you don't have to write very often, otherwise I can't imagine performance will be very good.
> You would need some sort of battery backed scratch/cache area to pull this off
Or a copy-on-write filesystem. With some tweaking they can essentially fill one zone by linearly writing new copies (and metadata) to it while garbage-collecting (copying GC, with compactation) old zones in the background
Re: HGST gets closer to shipping 10TB HDD
#4The 8 TB HDDs available now take a full 15 hours or so for a linear scan at max speed. God help you if you ever need to rebuild a RAID array made of them; the risk of an additional failure in say a RAID5 or RAID6 configuration is just too high.
We're nearing the point at which the throughput relative to the capacity and the risk of failure or corruption makes further capacity less and less useful, unless you're doing some pretty sophisticated replication, validation, & caching.
Re: HGST gets closer to shipping 10TB HDD
#5The 8 TB HDDs available now take a full 15 hours or so for a linear scan at max speed. God help you if you ever need to rebuild a RAID array made of them; the risk of an additional failure in say a RAID5 or RAID6 configuration is just too high. We're nearing the point at which the throughput relative to the capacity and the risk of failure or corruption makes further capacity less and less useful, unless you're doing…
Is there some fundamental obstacle that prevents raid rebuild times from being within a small, constant factor of linear scan time of a single disk?
Naively I would think that it would simply have to stream large chunks of each drive in parallel, apply the parity coding and write out the stream of calculated blocks to the new disk.
Re: HGST gets closer to shipping 10TB HDD
#6The 8 TB HDDs available now take a full 15 hours or so for a linear scan at max speed. God help you if you ever need to rebuild a RAID array made of them; the risk of an additional failure in say a RAID5 or RAID6 configuration is just too high. We're nearing the point at which the throughput relative to the capacity and the risk of failure or corruption makes further capacity less and less useful, unless you're doing…
Shingled drives are probably more likely used in a RAID-10 scenario where you're not recalculating parity, but just rebuilding linearly.
These drives (like the Western Digital Purple) are used predominantly for archival data. You should never have to randomly write to, for instance, surveillance video, or similar streamed media.
This isn't for your SQL database server.
Re: HGST gets closer to shipping 10TB HDD
#7The 8 TB HDDs available now take a full 15 hours or so for a linear scan at max speed. God help you if you ever need to rebuild a RAID array made of them; the risk of an additional failure in say a RAID5 or RAID6 configuration is just too high. We're nearing the point at which the throughput relative to the capacity and the risk of failure or corruption makes further capacity less and less useful, unless you're doing…
Can't this problem be partially solved by having more read/write heads? I don't think it will fit in the same form factor, but if the limit is how fast you can spin the disk then having multiple independently controlled read/write heads per platter seems like one way out of them problem.
Re: HGST gets closer to shipping 10TB HDD
#8The 8 TB HDDs available now take a full 15 hours or so for a linear scan at max speed. God help you if you ever need to rebuild a RAID array made of them; the risk of an additional failure in say a RAID5 or RAID6 configuration is just too high. We're nearing the point at which the throughput relative to the capacity and the risk of failure or corruption makes further capacity less and less useful, unless you're doing…
the risk of an additional failure in say a RAID5 or RAID6 configuration is just too high.
Two disk failures in the same array within 15 hours is very rare.
Re: HGST gets closer to shipping 10TB HDD
#9Before people make too many comments about the complexity and speed of these drives, it is important to realise that these drives are designed for append-mostly archival of data.
Re: HGST gets closer to shipping 10TB HDD
#10[deleted]