Lightbits storage performance significantly worse on Ubuntu

[Gerrit91]

Through our integration tests we see worse performance on latest Ubuntu images as compared to Debian compared in bandwidth. It happens consistently, so I assume it's also reproducible:

Ubuntu:

JobName: read_bw
  blocksize=128K filesize=2G iodepth=64 rw=randread
read:
  IOPS=4377.082031 BW(KiB/s)=560803
  iops: min=3 max=5440 avg=4381.500000
  bw(KiB/s): min=416000 max=696432 avg=560838.625000
JobName: write_bw
  blocksize=128k filesize=2G iodepth=64 rw=randwrite
write:
  IOPS=2626.031494 BW(KiB/s)=336668
  iops: min=1480 max=3428 avg=2630.533447
  bw(KiB/s): min=189440 max=438784 avg=336714.593750

Debian:

JobName: read_bw
  blocksize=128K filesize=2G iodepth=64 rw=randread
read:
  IOPS=11508.594727 BW(KiB/s)=1473637
  iops: min=10136 max=13312 avg=11519.466797
  bw(KiB/s): min=1297408 max=1704016 avg=1474495.375000
JobName: write_bw
  blocksize=128k filesize=2G iodepth=64 rw=randwrite
write:
  IOPS=3905.313721 BW(KiB/s)=500417
  iops: min=2004 max=5360 avg=3910.633301
  bw(KiB/s): min=512 max=686080 avg=500564.875000

[majst01]

Make me sad, have actually no idea what the reason for that might be.