[brianwski]

Disclaimer: I work at Backblaze but I'm on the software side, I barely ever touch the storage pods anymore.

It is not true that the pod team must remove the 4U server from the rack. It is slid out like a drawer (no tools required, takes maybe 10 seconds). The drive or motherboard is then replaced, then you slide the drawer back in. So the 4U server must slide 18 inches one way, but zero cables have to be unplugged or replugged when done. This only takes one technician and no "server lift", the drawer supports all the weight.

I'm not defending this design, just correcting a mistake. Backblaze frankly "makes do" with this design because nobody will step up and make anything that fits our needs better. The number 1 criteria is total system cost over the lifetime of the system INCLUDING all the time spent on salaries of datacenter techs dealing with the pods. "raw I/O performance" is not that important for backup, so trying to sell us an awesome EMC or NetApp that costs 10x as much and has 10x the raw I/O performance is not very compelling to us. But if you came up with a design making it faster for our datacenter technicians to replace a drive faster while not significantly increasing overall costs in another area, we SURELY would listen.

[dmourati]

Thanks for the clarification. That the PODs were on rails was never made clear to me. Still, I count that as "physically removing a 4u rackmount storage pod." Those suckers cannot be light. 10 seconds sounds rather fast. I don't imagine you could do it that fast for any of the upper pods.

While I don't recommend them outright, we settled on 3U boxes from SuperMicro. http://www.supermicro.com/products/chassis/3u/837/sc837e26-r...

We somewhat affectionately dubbed them "mullets" as in business in the front, party in the rear.

They make 4U devices as well. Cost was about $1000. We added LSI Megaraid 9280 controllers, about another $1500 and ran min-SAS back to a controller node responsible for 4 JBODs.

[secabeen]

It's a different trade-off. The Supermicro boxes use drive trays, so swapping a hard drive requires a datacenter tech to handle the tray mounting and unmounting. The PODs just drop drives right in. They've traded off tray mounting work for chassis sliding.

[atYevP]

Yev at Backblaze | One of our designs was for an aluminum pod..it made it..."lighter". :)