mirror_zfs/cmd
Arshad Hussain 677cdf7865
vdev_id: Support daisy-chained JBODs in multipath mode
Within function sas_handler() userspace commands like
'/usr/sbin/multipath' have been replaced with sourcing
device details from within sysfs which reduced a
significant amount of overhead and processing time.
Multiple JBOD enclosures and their order are sourced
from the bsg driver (/sys/class/enclosure) to isolate
chassis top-level expanders, which are then dynamically
indexed based on host channel of the multipath subordinate
disk member device being processed. Additionally added a
"mixed" mode for slot identification for environments where
a ZFS server system may contain SAS disk slots where there
is no expander (direct connect to HBA) while an attached
external JBOD with an expander have different slot identifier
methods.

How Has This Been Tested?
~~~~~~~~~~~~~~~~~~~~~~~~~

Testing was performed on a AMD EPYC based dual-server
high-availability multipath environment with multiple
HBAs per ZFS server and four SAS JBODs. The two primary
JBODs were multipath/cross-connected between the two
ZFS-HA servers. The secondary JBODs were daisy-chained
off of the primary JBODs using aligned SAS expander
channels (JBOD-0 expanderA--->JBOD-1 expanderA,
          JBOD-0 expanderB--->JBOD-1 expanderB, etc).
Pools were created, exported and re-imported, imported
globally with 'zpool import -a -d /dev/disk/by-vdev'.
Low level udev debug outputs were traced to isolate
and resolve errors.

Result:
~~~~~~~

Initial testing of a previous version of this change
showed how reliance on userspace utilities like
'/usr/sbin/multipath' and '/usr/bin/lsscsi' were
exacerbated by increasing numbers of disks and JBODs.
With four 60-disk SAS JBODs and 240 disks the time to
process a udevadm trigger was 3 minutes 30 seconds
during which nearly all CPU cores were above 80%
utilization. By switching reliance on userspace
utilities to sysfs in this version, the udevadm
trigger processing time was reduced to 12.2 seconds
and negligible CPU load.

This patch also fixes few shellcheck complains.

Reviewed-by: Gabriel A. Devenyi <gdevenyi@gmail.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Jeff Johnson <jeff.johnson@aeoncomputing.com>
Signed-off-by: Jeff Johnson <jeff.johnson@aeoncomputing.com>
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Closes #11526
2021-02-09 13:04:09 -08:00
..
arc_summary arc_summary3: Handle overflowing value width 2020-12-11 10:29:53 -08:00
arcstat FreeBSD: Update usage of py-sysctl 2020-12-10 15:28:31 -08:00
dbufstat dbufstat: Fix warnings with Python 3.8 2020-12-23 15:10:35 -08:00
fsck_zfs Fix typos in cmd/ 2019-08-30 09:43:30 -07:00
mount_zfs cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
raidz_test cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
vdev_id vdev_id: Support daisy-chained JBODs in multipath mode 2021-02-09 13:04:09 -08:00
zdb Add zdb -r <dataset> <object-id | file> <output> 2021-01-27 21:36:01 -08:00
zed Fixed issue with processing of EC_dev_remove event 2021-02-05 08:30:50 -08:00
zfs cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zfs_ids_to_path cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zgenhostid cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zhack cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zinject cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zpool cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zpool_influxdb cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zstream cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zstreamdump Minor zstream redup command fixes 2020-04-10 21:10:09 -07:00
ztest cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zvol_id cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
zvol_wait zvol_wait should ignore redacted zvols 2019-11-06 10:51:19 -08:00
Makefile.am cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00