Re: Boot problem if a ZFS log device is missing
On 30/08/2013 12.46, Andriy Gapon wrote: on 30/08/2013 13:37 Andriy Gapon said the following: on 30/08/2013 00:38 Charles Sprickman said the following: If one is willing to accept that data is lost (like the log device is totally smoked), is there a way to boot knowing that you may have some data loss, or is the only option to boot alternate media and force a pool import (assuming that works without the log device)? I think it's the latter. I am not aware of any way to select a behavior similar to import -m or import -F during boot. Perhaps... ZFS_IMPORT_MISSING_LOG should be a default behavior for a root pool or maybe the behavior could be controllable by a tunable. Maurizio, you might want to try the following patch as an interim solution for your environment: --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c @@ -4112,6 +4112,7 @@ spa_import_rootpool(const char *name) } spa->spa_is_root = B_TRUE; spa->spa_import_flags = ZFS_IMPORT_VERBATIM; + spa->spa_import_flags |= ZFS_IMPORT_MISSING_LOG; /* XXX make tunable */ /* * Build up a vdev tree based on the boot device's label config. HI all, unfortunately the patch don't works. The laptop returns the same error message: "Mounting from zfs:tank0 failed with error 6" and the same "mountroot>" prompt. I am available for further testing if needs. Thanks anyway, Maurizio ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
On 30/08/2013 13.45, Ronald Klop wrote: On Fri, 30 Aug 2013 12:58:29 +0200, Johan Hendriks wrote: Maurizio Vairani wrote: On 29/08/2013 11.01, Andriy Gapon wrote: on 29/08/2013 11:27 Maurizio Vairani said the following: I am able to boot the PC without a cache device but not without a log device. Why ? The log could potentially contain uncommitted entries. Without the log device there is no knowing if it did or did not. And if it did then the pool is inconsistent state without the log device and so it can not be imported. The cache is not persistent and so there is nothing needed from it upon a boot. Thank you for the clear and concise reply. Yesterday I have done some test. If I remove the stick from the USB port, before the shutdown the PC, it don't crash but continues to works. Then I am able to reboot the laptop without inserting the stick with a pool that works in degraded mode. From the end user point of view a PC should always boot, even with a missing ZFS log device. Regards Maurizio ___ freebsd...@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-fs To unsubscribe, send any mail to "freebsd-fs-unsubscr...@freebsd.org" I do not agree with the following. From the end user point of view a PC should always boot, even with a missing ZFS log device. I think it should give you a option to import the pool or not import the pool! No problem I agree, a step in the right direction. There could be a situation when you are not sure that the ZIL is commited, in that situation it would be handy if you can suspend the boot and make sure the ZIL is there when you reboot or import after you attached the ZIL. I would hate it when it corrups my data just because we always import. with or without the ZIL. In your test you remove the ZIL, and when you reboot then it imports correctly, as far as my knowledge goes this is ok, because when the pool is exported there is no left data in the ZIL, it was not there when we exported, so we can import even without the missing ZIL without problem. I think he was just lucky his system wasn't writing a lot to the ZIL at the moment of removal. So his system was in a consistent state. Otherwise you just miss data which is in the ZIL and not on disk. I have removed the stick when there isn't R/W to the disk. BTW: Not everything goes through the ZIL. It is not the same as a journal. Only sync writes go to the ZIL. If you don't use databases or NFS or other software which wants to make sure data is on stable storage, you might rarely use the ZIL. Thanks for the explanation. Ronald. regards Johan ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" Regards Maurizio ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
On Fri, 30 Aug 2013 12:58:29 +0200, Johan Hendriks wrote: Maurizio Vairani wrote: On 29/08/2013 11.01, Andriy Gapon wrote: on 29/08/2013 11:27 Maurizio Vairani said the following: I am able to boot the PC without a cache device but not without a log device. Why ? The log could potentially contain uncommitted entries. Without the log device there is no knowing if it did or did not. And if it did then the pool is inconsistent state without the log device and so it can not be imported. The cache is not persistent and so there is nothing needed from it upon a boot. Thank you for the clear and concise reply. Yesterday I have done some test. If I remove the stick from the USB port, before the shutdown the PC, it don't crash but continues to works. Then I am able to reboot the laptop without inserting the stick with a pool that works in degraded mode. From the end user point of view a PC should always boot, even with a missing ZFS log device. Regards Maurizio ___ freebsd...@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-fs To unsubscribe, send any mail to "freebsd-fs-unsubscr...@freebsd.org" I do not agree with the following. From the end user point of view a PC should always boot, even with a missing ZFS log device. I think it should give you a option to import the pool or not import the pool! There could be a situation when you are not sure that the ZIL is commited, in that situation it would be handy if you can suspend the boot and make sure the ZIL is there when you reboot or import after you attached the ZIL. I would hate it when it corrups my data just because we always import. with or without the ZIL. In your test you remove the ZIL, and when you reboot then it imports correctly, as far as my knowledge goes this is ok, because when the pool is exported there is no left data in the ZIL, it was not there when we exported, so we can import even without the missing ZIL without problem. I think he was just lucky his system wasn't writing a lot to the ZIL at the moment of removal. So his system was in a consistent state. Otherwise you just miss data which is in the ZIL and not on disk. BTW: Not everything goes through the ZIL. It is not the same as a journal. Only sync writes go to the ZIL. If you don't use databases or NFS or other software which wants to make sure data is on stable storage, you might rarely use the ZIL. Ronald. regards Johan ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
Maurizio Vairani wrote: On 29/08/2013 11.01, Andriy Gapon wrote: on 29/08/2013 11:27 Maurizio Vairani said the following: I am able to boot the PC without a cache device but not without a log device. Why ? The log could potentially contain uncommitted entries. Without the log device there is no knowing if it did or did not. And if it did then the pool is inconsistent state without the log device and so it can not be imported. The cache is not persistent and so there is nothing needed from it upon a boot. Thank you for the clear and concise reply. Yesterday I have done some test. If I remove the stick from the USB port, before the shutdown the PC, it don't crash but continues to works. Then I am able to reboot the laptop without inserting the stick with a pool that works in degraded mode. From the end user point of view a PC should always boot, even with a missing ZFS log device. Regards Maurizio ___ freebsd...@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-fs To unsubscribe, send any mail to "freebsd-fs-unsubscr...@freebsd.org" I do not agree with the following. From the end user point of view a PC should always boot, even with a missing ZFS log device. I think it should give you a option to import the pool or not import the pool! There could be a situation when you are not sure that the ZIL is commited, in that situation it would be handy if you can suspend the boot and make sure the ZIL is there when you reboot or import after you attached the ZIL. I would hate it when it corrups my data just because we always import. with or without the ZIL. In your test you remove the ZIL, and when you reboot then it imports correctly, as far as my knowledge goes this is ok, because when the pool is exported there is no left data in the ZIL, it was not there when we exported, so we can import even without the missing ZIL without problem. regards Johan ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
on 30/08/2013 13:37 Andriy Gapon said the following: > on 30/08/2013 00:38 Charles Sprickman said the following: >> If one is willing to accept that data is lost (like the log device is >> totally smoked), is there a way to boot knowing that you may have some data >> loss, or is the only option to boot alternate media and force a pool import >> (assuming that works without the log device)? > > I think it's the latter. I am not aware of any way to select a behavior > similar > to import -m or import -F during boot. > Perhaps... ZFS_IMPORT_MISSING_LOG should be a default behavior for a root pool > or maybe the behavior could be controllable by a tunable. > Maurizio, you might want to try the following patch as an interim solution for your environment: --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c @@ -4112,6 +4112,7 @@ spa_import_rootpool(const char *name) } spa->spa_is_root = B_TRUE; spa->spa_import_flags = ZFS_IMPORT_VERBATIM; + spa->spa_import_flags |= ZFS_IMPORT_MISSING_LOG; /* XXX make tunable */ /* * Build up a vdev tree based on the boot device's label config. -- Andriy Gapon ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
on 30/08/2013 00:38 Charles Sprickman said the following: > If one is willing to accept that data is lost (like the log device is totally > smoked), is there a way to boot knowing that you may have some data loss, or > is the only option to boot alternate media and force a pool import (assuming > that works without the log device)? I think it's the latter. I am not aware of any way to select a behavior similar to import -m or import -F during boot. Perhaps... ZFS_IMPORT_MISSING_LOG should be a default behavior for a root pool or maybe the behavior could be controllable by a tunable. -- Andriy Gapon ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
On 29/08/2013 11.01, Andriy Gapon wrote: on 29/08/2013 11:27 Maurizio Vairani said the following: I am able to boot the PC without a cache device but not without a log device. Why ? The log could potentially contain uncommitted entries. Without the log device there is no knowing if it did or did not. And if it did then the pool is inconsistent state without the log device and so it can not be imported. The cache is not persistent and so there is nothing needed from it upon a boot. Thank you for the clear and concise reply. Yesterday I have done some test. If I remove the stick from the USB port, before the shutdown the PC, it don't crash but continues to works. Then I am able to reboot the laptop without inserting the stick with a pool that works in degraded mode. From the end user point of view a PC should always boot, even with a missing ZFS log device. Regards Maurizio ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
On Aug 29, 2013, at 5:01 AM, Andriy Gapon wrote: > on 29/08/2013 11:27 Maurizio Vairani said the following: >> >> I am able to boot the PC without a cache device but not without a log >> device. Why ? > > The log could potentially contain uncommitted entries. Without the log device > there is no knowing if it did or did not. And if it did then the pool is > inconsistent state without the log device and so it can not be imported. If one is willing to accept that data is lost (like the log device is totally smoked), is there a way to boot knowing that you may have some data loss, or is the only option to boot alternate media and force a pool import (assuming that works without the log device)? Charles > > The cache is not persistent and so there is nothing needed from it upon a > boot. > > -- > Andriy Gapon > ___ > freebsd...@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscr...@freebsd.org" ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: Boot problem if a ZFS log device is missing
on 29/08/2013 11:27 Maurizio Vairani said the following: > > I am able to boot the PC without a cache device but not without a log device. > Why ? The log could potentially contain uncommitted entries. Without the log device there is no knowing if it did or did not. And if it did then the pool is inconsistent state without the log device and so it can not be imported. The cache is not persistent and so there is nothing needed from it upon a boot. -- Andriy Gapon ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Boot problem if a ZFS log device is missing
Hi all, I am using an USB memory stick as cache and log devices for a HDD ZFS pool named tank0: $ zpool status -v tank0 pool: tank0 state: ONLINE scan: scrub repaired 0 in 7h19m with 0 errors on Tue Jul 30 06:11:23 2013 config: NAME STATE READ WRITE CKSUM tank0ONLINE 0 0 0 ada0s1dONLINE 0 0 0 logs gpt/SLOG ONLINE 0 0 0 cache gpt/L2ARC ONLINE 0 0 0 errors: No known data errors If I remove the stick before booting the laptop (a Compaq Presario) it will not boot with the error message: "Mounting from zfs:tank0 failed with error 6" end the mountroot> prompt is displayed. I need to reinsert the stick to completing the boot process before restarting the laptop. It is possible to boots the laptop without stick if I remove the log device with the command: # zpool remove tank0 gpt/SLOG before switching it off. The pool will works in degraded mode because the cache device is missing, but it works. I am able to boot the PC without a cache device but not without a log device. Why ? The laptop is updated to 9.2-PRERELEASE r254783. Regards Maurizio ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
