illumos/illumos-gate@e144c4e6c9
Currently `zdb` consistently fails to examine non-idle pools as it fails
during the `spa_load()` process. The main problem seems to be that
`spa_load_verify()` fails as can be seen below:
$ sudo zdb -d -G dcenter
zdb: can't open 'dcenter': I/O error
ZFS_DBGMSG(zdb):
spa_open_common: opening dcenter
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c4t11d0s0': best uberblock found for spa dcenter. txg 40824950
spa_load(dcenter): using uberblock with txg=40824950
spa_load(dcenter): UNLOADING
spa_load(dcenter): RELOADING
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c3t10d0s0': best uberblock found for spa dcenter. txg 40824952
spa_load(dcenter): using uberblock with txg=40824952
spa_load(dcenter): FAILED: spa_load_verify failed [error=5]
spa_load(dcenter): UNLOADING
This change makes `spa_load_verify()` a dryrun when ran from `zdb`. This is
done by creating a global flag in zfs and then setting it in `zdb`.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andy Stormont <astormont@racktopsystems.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>