zfs-fuse: error detaching device (Was: Re: zfs-fuse stuff)

[Durval Menezes]

Hello Gordan, 

Using your version from the GIT here, cloned 2015-05-27 23:35 GMT, with Linux Mint 17, successfully for a few months  now; no issues until today. 

I'm getting "no such device in pool" errors when trying to detach a vdev from a mirror:

zpool status

              pool: HD_ARCHIVE_0009

             state: ONLINE

            status: The pool is formatted using an older on-disk format.  The pool can

                    still be used, but some features are unavailable.

            action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the

                    pool will no longer be accessible on older software versions.

             scan: resilvered 119G in 5h20m with 0 errors on Wed May  4 00:24:54 2016

            config: 

                    NAME                                      STATE     READ WRITE CKSUM

                    HD_ARCHIVE_0009                           ONLINE       0     0     0

                      mirror-0                                ONLINE       0     0     0

                        disk/by-id/dm-name-ZFS_ARCHIVE_0009f  ONLINE       0     0     0

                        disk/by-id/dm-name-ZFS_ARCHIVE_0009c  ONLINE       0     0     0

            errors: No known data errors

zpool detach HD_ARCHIVE_0009 disk/by-id/dm-name-ZFS_ARCHIVE_0009c

cannot detach disk/by-id/dm-name-ZFS_ARCHIVE_0009c: no such device in pool

As an old ZFS hand, I've seen these errors happen before (with ZoL) and they happened, I was always able to detach the device using its GUID:

zdb HD_ARCHIVE_0009 | less

                                [...]

                                guid: 2748028746382267204

                                path: '/dev/disk/by-id/dm-name-ZFS_ARCHIVE_0009c'

                                [...]

But not this time: 

zpool detach HD_ARCHIVE_0009 2748028746382267204

                    cannot detach 2748028746382267204: no such device in pool

Can you tell me whether this is a known issue with zfs-fuse or your version, or that I'm messing things up somewhere? 

Thanks, 

-- 

   Durval.

On Thu, May 28, 2015 at 6:22 AM, Gordan Bobic <gordan...@gmail.com> wrote:

FYI, the next thing I'm planning to do with zfs-fuse is backport ZoL's zfs-dracut package so that I can get rootfs on zfs-fuse working without manual intervention.

I would also love to figure out and fix whatever is causing this to flood my syslog:
zfs-fuse: sending ioctl 2285 to a partition!

AFAICT zfs-fuse is sending an ioctl to flush the caches, but when ZFS is on partitions, it invokes it on partitions rather than underlying block devices. I'm not 100% sure but I think what it should be doing instead is a simple fsync() instead, but I'm not 100% sure, and the interest in zfs-fuse from experts like Emmanuel and Seth seems to be at an all time low. :-(

On Thu, May 28, 2015 at 12:40 AM, Durval Menezes <durval....@gmail.com> wrote:

Hi Gordan,

On Wed, May 27, 2015 at 8:26 PM, Durval Menezes <durval....@gmail.com> wrote:

Sure, got them all here, and was about to clone your new git repository and compile some fresh packages here using it.

Just cloned it and I'm having a look around. Found that on the top-level INSTALL file:

 Currently, it only works on the x86, amd64 and sparc64 architectures.

Shouldn't this be updated to reflect the fact that it also runs fine on ARM?

Cheers,
--

   Durval.

[Durval Menezes]

Hello list folks, and Gordan, 

Just keeping everyone posted: the 'zfs detach' command that failed with zfs-fuse with either the device name or the device guid, succeeded with ZFS-On-Linux version 0.6.5.6-1 using the guid (it failed too, with the same error, when specifying the device name, but in my experience this is a bug so old it's almost a "feature").

Cheers, 

-- 

   Durval Menezes.