ZFS bug: Creating ZIL ignores vfs.zfs.min_auto_ashift

[Borja Marcos]

On Nov 6, 2014, at 2:02 PM, Steven Hartland wrote:

> Your zdb output looks strange you have two children[1] entries are you sure your pool is not corrupt?

As far as I know, it's working fine, no need to summon the guardian of the lost children ;)

The extra "children" is the log device. I have verified it in a completely virgin (pun intended) system and indeed the log device
appears as a new "children" branch.



Let's see. This is the output without log or anything. Just a mirror.

# zpool status
  pool: rpool
 state: ONLINE
  scan: scrub repaired 0 in 5h55m with 0 errors on Wed Oct 29 23:26:03 2014
config:

	NAME        STATE     READ WRITE CKSUM
	rpool       ONLINE       0     0     0
	  mirror-0  ONLINE       0     0     0
	    ada0p3  ONLINE       0     0     0
	    ada2p3  ONLINE       0     0     0

errors: No known data errors
# 


# zdb|more
rpool:
    version: 5000
    name: 'rpool'
    state: 0
    txg: 11739617
    pool_guid: 18110845055860026534
    hostid: 316898903
    hostname: 'splunk'
    vdev_children: 1
    vdev_tree:
        type: 'root'
        id: 0
        guid: 18110845055860026534
        children[0]:
            type: 'mirror'
            id: 0
            guid: 10858793804082837265
            metaslab_array: 30
            metaslab_shift: 32
            ashift: 12
            asize: 482922987520
            is_log: 0
            create_txg: 4
            children[0]:
                type: 'disk'
                id: 0
                guid: 10490056043151312448
                path: '/dev/ada0p3'
                phys_path: '/dev/ada0p3'
                whole_disk: 1
                DTL: 331
                create_txg: 4
            children[1]:
                type: 'disk'
                id: 1
                guid: 2441255496794840851
                path: '/dev/ada2p3'
                phys_path: '/dev/ada2p3'
                whole_disk: 1
                DTL: 252
                create_txg: 4
    features_for_read:
        com.delphix:hole_birth
        com.delphix:embedded_data

If I add a zil,

zdb|more
rpool:
    version: 5000
    name: 'rpool'
    state: 0
    txg: 11741324
    pool_guid: 18110845055860026534
    hostid: 316898903
    hostname: 'splunk'
    vdev_children: 2
    vdev_tree:
        type: 'root'
        id: 0
        guid: 18110845055860026534
        children[0]:
            type: 'mirror'
            id: 0
            guid: 10858793804082837265
            metaslab_array: 30
            metaslab_shift: 32
            ashift: 12
            asize: 482922987520
            is_log: 0
            create_txg: 4
            children[0]:
                type: 'disk'
                id: 0
                guid: 10490056043151312448
                path: '/dev/ada0p3'
                phys_path: '/dev/ada0p3'
                whole_disk: 1
                DTL: 331
                create_txg: 4
            children[1]:
                type: 'disk'
                id: 1
                guid: 2441255496794840851
                path: '/dev/ada2p3'
                phys_path: '/dev/ada2p3'
                whole_disk: 1
                DTL: 252
                create_txg: 4
        children[1]:
            type: 'disk'
            id: 1
            guid: 16071425471468142310
            path: '/dev/ada1'
            phys_path: '/dev/ada1'
            whole_disk: 1
            metaslab_array: 0
            metaslab_shift: 0
            ashift: 9
            asize: 40015757312
            is_log: 1
            create_txg: 11741324
    features_for_read:
        com.delphix:hole_birth
        com.delphix:embedded_data