Add support for devid and phys_path keys in vdev disk labels

This is foundational work for ZED.

Updates a leaf vdev's persistent device strings on Linux platform

* only applies for a dedicated leaf vdev (aka whole disk)
* updated during pool create|add|attach|import
* used for matching device matching during auto-{online,expand,replace}
* stored in a leaf disk config label (i.e. alongside 'path' NVP)
* can opt-out using env var ZFS_VDEV_DEVID_OPT_OUT=YES

Some examples:

    path: '/dev/sdb1'
    devid: 'scsi-350000394a8ca4fbc-part1'
    phys_path: 'pci-0000:04:00.0-sas-0x50000394a8ca4fbf-lun-0'

    path: '/dev/mapper/mpatha'
    devid: 'dm-uuid-mpath-35000c5006304de3f'

Signed-off-by: Don Brady <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2856
Closes #3978
Closes #4416

1 files changed, 11 insertions, 0 deletions

diff --git a/man/man8/zpool.8 b/man/man8/zpool.8
index 2d92a7502..4a7a46bdd 100644
--- a/man/man8/zpool.8
+++ b/man/man8/zpool.8
@@ -2603,6 +2603,17 @@ Cause \fBzpool\fR subcommands to follow links for vdev names by default.  This b
 .B "ZPOOL_VDEV_NAME_PATH"
 Cause \fBzpool\fR subcommands to output full vdev path names by default.  This
 behavior is identical to the \fBzpool status -p\fR command line option.
+.TP
+.B "ZFS_VDEV_DEVID_OPT_OUT"
+Older ZFS on Linux implementations had issues when attempting to display pool
+config VDEV names if a "devid" NVP value is present in the pool's config.
+
+For example, a pool that originated on illumos platform would have a devid
+value in the config and \fBzpool status\fR would fail when listing the config.
+This would also be true for future Linux based pools.
+
+A pool can be stripped of any "devid" values on import or prevented from adding
+them on \fBzpool create\fR or \fBzpool add\fR by setting ZFS_VDEV_DEVID_OPT_OUT.
 
 .SH SEE ALSO
 .sp