We have a public server that provides mirror service for a variety of open-source software, like Ubuntu, Debian, CentOS and PyPI, RubyGems, CPAN, etc. Our daily outgoing network goes from 10 TB to 12 TB and all our disks are running at 95% or higher. We've been running short of storage capacity for some time and are looking for some expansion.
We're looking for an expansion array with around 40 TB of raw storage (sum of all disks) with enough I/O performance. We also want to reduce the cost, although we're not trying too hard to minimize it. Our server has an empty PCIe 3.0 x16 slot and two free optical fiber ports for connecting with the new array. The cabinet is free such that anything under 6U should fit.