5 ms·

The only storage array I know of that comes as a sealed unit where you don't do drive swaps, is the Xiostorage ISE [1]. It's a very fast array for the money, bu

by EwanToo 14y ago

The only storage array I know of that comes as a sealed unit where you don't do drive swaps, is the Xiostorage ISE [1]. It's a very fast array for the money, but it's not particularly high-end. All the high end arrays, both in terms of performance and availability (IBM DS8000, EMC Symmetrix / V-Max, etc) have done drive swaps for as long as I've used them. Without drive swaps, you either have to abandon traditional RAID concepts, which might not be a bad thing, or ship with enough standby disks to cope with 5 years of failures. 1 - http://xiostorage.com/products/hyper-ise/ http://xiostorage.com/products/hyper-ise/

regularfry 14y ago
The place I heard first not doing drive swaps was Google. I also heard that they didn't use RAID, but rather relied on data just being replicated over 3 separate machines. Both of these may have been apocryphal. I'm sure someone around here can correct me if so :-)
- EwanToo 14y ago
  Google (and others like AWS) don't use RAID, that's absolutely right - but they also don't use arrays from the regular manufacturers like EMC, NetApp, etc. Whether they eventually get around to swapping out failed drives or not, I don't know. I assume they do, since a CPU and memory costs a lot more than a drive replacement, so you want to keep them up and running.
  - TillE 14y ago
    I imagine they'd swap out the whole blade as a quick fix, but then have it diagnosed, repaired, and put back into service. Makes more sense than trying to fiddle around with a defective server while it's still in the rack.
- justincormack 14y ago
  I first came across them in IBM's ice cube project around 2002 http://www.eetimes.com/electronics-news/4165609/IBM-stacks-hard-disk-bricks-to-build-dense-storage-cube http://www.eetimes.com/electronics-news/4165609/IBM-stacks-h... which was later spun out into a startup and then canned. I think this was before the Google fail in place stuff. Because it was a 3d mesh you actually couldn't get to the hardware to replace it. They had blocks of 12 drives to offset some of the drive to CPU cost issues. There are a bunch of papers on it if you dig around and its still an interesting model I think.
- bcoates 14y ago
  Right, that's the kind of system I was thinking of: Not off the shelf enterprise RAID enclosures, but big piles of commodity drives run by companies that do storage as their business, like Google and Backblaze and Facebook.

by EwanToo 14y ago

regularfry 14y ago

The place I heard first not doing drive swaps was Google. I also heard that they didn't use RAID, but rather relied on data just being replicated over 3 separate machines. Both of these may have been apocryphal. I'm sure someone around here can correct me if so :-)

EwanToo 14y ago
Google (and others like AWS) don't use RAID, that's absolutely right - but they also don't use arrays from the regular manufacturers like EMC, NetApp, etc. Whether they eventually get around to swapping out failed drives or not, I don't know. I assume they do, since a CPU and memory costs a lot more than a drive replacement, so you want to keep them up and running.
- TillE 14y ago
  I imagine they'd swap out the whole blade as a quick fix, but then have it diagnosed, repaired, and put back into service. Makes more sense than trying to fiddle around with a defective server while it's still in the rack.
justincormack 14y ago
I first came across them in IBM's ice cube project around 2002 http://www.eetimes.com/electronics-news/4165609/IBM-stacks-hard-disk-bricks-to-build-dense-storage-cube http://www.eetimes.com/electronics-news/4165609/IBM-stacks-h... which was later spun out into a startup and then canned. I think this was before the Google fail in place stuff. Because it was a 3d mesh you actually couldn't get to the hardware to replace it. They had blocks of 12 drives to offset some of the drive to CPU cost issues. There are a bunch of papers on it if you dig around and its still an interesting model I think.
bcoates 14y ago
Right, that's the kind of system I was thinking of: Not off the shelf enterprise RAID enclosures, but big piles of commodity drives run by companies that do storage as their business, like Google and Backblaze and Facebook.