Comment 0 for bug 1668557

Upgrading our HP(E) servers to xenial we have discovered a severe performance regression affecting write performance on Smart Array RAID logical drives.

Firmware is up to date with latest HPE SPP release at the time of testing.

This performance regression has been verified on multiple sites with different HPE systems and OS:s, downgrading kernel brings back the expected performance.

We are NOT seeing this on Dell hardware with H730P (LSI based) controllers, using the same OS installs.

Our test system setup:

Ubuntu 16.04.2 LTS
Server: HP(E) DL380e, 36 G RAM, 1x E5-2420 CPU
RAID Controller: Smart Array P420 2GB FBWC
RAID setup: 24x 500G SAS HDDs in RAID50 with 2 parity groups.
File system: xfs

We are also seeing this issue on setups using DL380e with P430 controller and 14 HDDs in RAID6, but those systems are not available for testing.

Fast/normal (previous) bulk IO performance is approx 1600-1800 MB/s sustained read and write using a simple dd bs=256k based test.

Slow/performance regression reduces the write performance to approx 500-600 MB/s sustained using the same tests and filesystem.

We have tested using the following OS installs and kernels:

Precise:

All tested Ubuntu kernels are fast.

Trusty:

trusty 3.13.0.110.118 fast
utopic 3.16.0.77.68 fast
vivid 3.19.0.80.62 slow
xenial 4.4.0.64.50 slow

Xenial:

xenial 4.4.0.64.68 slow
hwe 4.8.0.39.10 slow

mainline 3.12.64-031264.201610030943 fast
mainline 3.16.41-031641.201702270232 fast
mainline 3.17.8-031708.201501081837 fast
mainline 3.18.0-031800.201412071935 fast
mainline 3.18.12-031812.201504221338 fast
mainline 3.18.18-031818.201507101433 fast
mainline 3.18.21-031821.201509020527 fast
mainline 3.18.22-031822.201510031227 slow
mainline 3.18.23-031823.201510291931 slow
mainline 3.18.24-031824.201511031331 slow
mainline 3.18.47-031847.201701181631 slow
mainline 4.10.1-041001.201702260735 slow