Glen Barber
2018-Oct-22 14:15 UTC
krpc: unbootable ZFS-on-root after major upgrade to 11.2
On Mon, Oct 22, 2018 at 09:09:14PM +0700, Eugene Grosbein wrote:> 22.10.2018 21:03, Glen Barber wrote: > > t's strange that this is a 10.x vs 11.x issue. > >>> I see that zfs has the krpc dependency since r193128. > >>> And the call to xdrmem_create is there since r168404. > >> > >> You are right. I was mis-informed and have not verified enough a report from local user. > >> > >> Glen, maybe that errata record should be deleted. The problem is real but it is long-standing > >> and present in 10.x too. > >> > > > > Could you elaborate more on the failure case you originally reported > > first? If the problem is real, my feeling is that the errata entry > > should stay, just worded differently to reflect the failure case here. > > zfs.ko depends on krpc.ko. The KRPC code in compiled in GENERIC kernel as dependency > of NFS client/server code. The problem arises if all of these are true: > > 1) a system uses custom kernel with NFS options removed; > 2) there is no krpc.ko available due to MODULES_OVERRIDE excluding it; > 3) the system boots off ZFS pool. > > In such case, loader cannot resolve dependency and fails to load zfs.ko > and kernel fails to mount root breaking boot sequence. > >So, if I understand correctly (and please correct me if I am wrong), the majority of the text in the errata note is correct, however needs to be tweaked to remove "upgrading from 10.x...". Is this generally correct? Glen -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: <http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20181022/3bee3ad0/attachment.sig>
Andriy Gapon
2018-Oct-22 14:21 UTC
krpc: unbootable ZFS-on-root after major upgrade to 11.2
On 22/10/2018 17:15, Glen Barber wrote:> On Mon, Oct 22, 2018 at 09:09:14PM +0700, Eugene Grosbein wrote: >> 22.10.2018 21:03, Glen Barber wrote: >> >> t's strange that this is a 10.x vs 11.x issue. >>>>> I see that zfs has the krpc dependency since r193128. >>>>> And the call to xdrmem_create is there since r168404. >>>> >>>> You are right. I was mis-informed and have not verified enough a report from local user. >>>> >>>> Glen, maybe that errata record should be deleted. The problem is real but it is long-standing >>>> and present in 10.x too. >>>> >>> >>> Could you elaborate more on the failure case you originally reported >>> first? If the problem is real, my feeling is that the errata entry >>> should stay, just worded differently to reflect the failure case here. >> >> zfs.ko depends on krpc.ko. The KRPC code in compiled in GENERIC kernel as dependency >> of NFS client/server code. The problem arises if all of these are true: >> >> 1) a system uses custom kernel with NFS options removed; >> 2) there is no krpc.ko available due to MODULES_OVERRIDE excluding it; >> 3) the system boots off ZFS pool. >> >> In such case, loader cannot resolve dependency and fails to load zfs.ko >> and kernel fails to mount root breaking boot sequence. >> >> > > So, if I understand correctly (and please correct me if I am wrong), the > majority of the text in the errata note is correct, however needs to be > tweaked to remove "upgrading from 10.x...". Is this generally correct?This is just a typical foot-shooting (and a shortcoming of the kernel build system that allows such foot-shooting to happen). I think that there can be other ways in which you can specify inconsistent kernel options and/or an incorrect subset of modules in MODULES_OVERRIDE to create missing dependencies for critical modules. Do we want to issue an errata for each possible misconfiguration? -- Andriy Gapon