round-robin is a basic selector, and only works well under ideal conditions,
A nvme benchmark, round-robin vs queue-depth, shows how bad it is: https://marc.info/?l=linux-kernel&m=171931850925572 https://marc.info/?l=linux-kernel&m=171931852025575 https://github.com/johnmeneghini/iopolicy/?tab=readme-ov-file#sample-data https://people.redhat.com/jmeneghi/ALPSS_2023/NVMe_QD_Multipathing.pdf The same happens for scsi. Cc: Martin Wilck <mwi...@suse.com> Cc: Benjamin Marzinski <bmarz...@redhat.com> Cc: Christophe Varoqui <christophe.varo...@opensvc.com> Cc: DM-DEVEL ML <dm-devel@lists.linux.dev> Signed-off-by: Xose Vazquez Perez <xose.vazq...@gmail.com> --- Should global keywords be banned in the devices section, or deleted from hwtable ??? dev_loss fast_io_fail max_sectors_kb ... They interfere when two, or more, different arrays are connected to the same host. --- libmultipath/hwtable.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c index 081d119c..3ade3669 100644 --- a/libmultipath/hwtable.c +++ b/libmultipath/hwtable.c @@ -1125,11 +1125,7 @@ static struct hwentry default_hw[] = { .pgpolicy = GROUP_BY_PRIO, .pgfailback = 30, .prio_name = PRIO_ALUA, - .selector = "round-robin 0", - .rr_weight = RR_WEIGHT_PRIO, .no_path_retry = NO_PATH_RETRY_FAIL, - .minio = 1, - .minio_rq = 1, .fast_io_fail = 15, }, /* -- 2.49.0
