On Sun, Feb 25, 2018 at 10:00 PM, L A Walsh <suse@tlinx.org> wrote:
A few clarifications:
LSI MegaRaid 9286CV-8e. It has 8 external 6Gb channels.
--- Note: though the MegaRaid is a SAS controller, it will work with SATA disks as easily as SAS disks.
The LSI controller will be a bit finicky on disks it will accept as "good"...if you want good performance, you'll want to get Enterprise level drives.
--- Clarification: Drives that don't test good on a HW controller like the LSI will likely work on a software-raid. However "work" doesn't mean it will work well. The reason the LSI controller kicked many drives: RPMs out of spec, so instead of 7200RPM, a few were faster, seeming to be 7920 RPM drives -- a benefit if used as a single Desktop drive, though many were worse ... performing more like 5400 RPM drives.
9 out of 12 Deskstars were too far out of RPM range to be considered 'good' by the LSI controller.
Linda, If it's that picky, don't even think about a shingled drive (SMR). They can have very variable performance as the drive does internal housekeeping. In particular I occasionally stream a few TB at a time straight to an array. Even a 2TB front-end cache might fill up and kick in housekeeping that would trigger a drive eviction. Greg -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org