E-Series direct attached 12 Gb SAS performance degradation and long initialization
Applies to
- E2824
- TOSHIBA (Type: AL15SEB120N Firmware MS00)
Issue
- Initial setup of RAID 6 Volume Group of 6 HDD takes 10 Hours other disk type takes 3 hours
- Initial performance testing of the volume group does not meet sequential write performance expectations
- Errors in major event log during volume group creation and Host multipath errors disabling write cache
Examples:
Host multipath driver configuration error detected - Host abc <--CRITICAL
Cache database mismatch has been detected - Shelf 99, Bay B
$ fio --name=test --filesize=10G --directory=/mnt/fio --bs=2M --nrfiles=1 --direct=1 --sync=0 --randrepeat=0 --rw=read --refill_buffers --end_fsync=1 --iodepth=1 --ioengine=sync --runtime=30s --numjobs=4
READ: bw=873MiB/s (916MB/s), 210MiB/s-243MiB/s (220MB/s-255MB/s), io=25.6GiB (27.5GB), run=30001-30007msec
Sequential READ/WRITE 50/50 (2MiB blocks) test with 4 processes:
$ fio --name=test --filesize=10G --directory=/mnt/fio --bs=2M --nrfiles=1 --direct=1 --sync=0 --randrepeat=0 --rw=rw --refill_buffers --end_fsync=1 --iodepth=1 --ioengine=sync --runtime=30s --numjobs=4
READ: bw=285MiB/s (299MB/s), 67.5MiB/s-73.1MiB/s (70.8MB/s-76.6MB/s), io=8562MiB (8978MB), run=30021-30038msec
WRITE: bw=280MiB/s (293MB/s), 68.4MiB/s-73.8MiB/s (71.7MB/s-77.4MB/s), io=8402MiB (8810MB), run=30021-30038msec
Sequential WRITE (2MiB blocks) test with 4 processes
$ fio --name=test --filesize=10G --directory=/mnt/fio --bs=2M --nrfiles=1 --direct=1 --sync=0 --randrepeat=0 --rw=write --refill_buffers --end_fsync=1 --iodepth=1 --ioengine=sync --runtime=30s --numjobs=4
WRITE: bw=215MiB/s (226MB/s), 49.3MiB/s-65.7MiB/s (51.7MB/s-68.9MB/s), io=6468MiB (6782MB), run=30005-30073msec