Re: [linux-lvm] can't remove snapshot

["Lentes, Bernd" <bernd.lentes@helmholtz-muenchen.de>]

wer nichts macht kann auch nichts lernen

----- On Apr 11, 2019, at 7:25 PM, Bernd Lentes bernd.lentes@helmholtz-muenchen.de wrote:

> ----- On Apr 11, 2019, at 5:59 PM, Zdenek Kabelac zkabelac@redhat.com wrote:

>> So here is the reason:
>> 
>> ioctl: can't change device type after initial table load.
>> 
>> You already have snapshot-origin in the table - which likely is not what lvm2
>> would have expected - you could either try 'lvchange --refresh' to get the dm
>> table into matching state - or reboot and start from beginning.
>> 
>> Clearly you are not supposed to partial modify DM table targets yourself while
>> lvm2 holds the metadata state for them - so ATM it looks like lvm2 cannot
>> proceed with the command - as the content of DM node is different and
>> transition is not allowed.
>> 
>> lvm2 should probably detect the case sooner and report error about
>> incompatible state of device for present metadata (but this will not help
>> you to resolve the problem).
>> 
>> So waht you can do is to probably restore to the metadata you had before
>> you've took your snapshot and try change into this table - but looking into
>> your current DM table - such transition might be untrivial.
>> 
>> Is there a reason why you cannot reboot - as that's IMHO the simplest fix??
>> 
>> Regards
>> 
>> Zdenek
> 
> Hi Zdanek,
> 
> it's just that i don't like to reboot a linux system when i have problems, i
> prefer to find the solution
> so that there is no need to reboot. Then i feel a bit as being in front of a
> windows system :-)).
> 
> I rebooted, but problem persists:
> 
> ha-idg-2:~ # lvremove -fv /dev/vg_local/lv_snap_pre_sp4
>    Logging initialised at Thu Apr 11 19:15:02 2019
>    Set umask from 0022 to 0077
> lvremove  connect() failed on local socket: No such file or directory
> lvremove  Internal cluster locking initialisation failed.
> lvremove  WARNING: Falling back to local file-based locking.
> lvremove  Volume Groups with the clustered attribute will be inaccessible.
> lvremove    Archiving volume group "vg_local" metadata (seqno 26).
> lvremove    Removing snapshot volume vg_local/lv_snap_pre_sp4.
> lvremove    Loading table for vg_local-lv_root (254:9).
> lvremove  device-mapper: reload ioctl on  (254:9) failed: Invalid argument
> lvremove  Failed to refresh lv_root without snapshot.
> 
> My current config:
> ha-idg-2:~ # dmsetup -vc info
> Name                                    Maj Min Stat Open Targ Event  UUID
> vg_local-lv_root-real                   254   8 L--w    2    1      0
> LVM-btzX70eAWIejM6K1bcQnKNmnIOYaTODGt79QZ80zYmQrwddi2BBMObpN1gLssjEF-real
> vg_local-lv_var                         254  13 L--w    1    1      0
> LVM-btzX70eAWIejM6K1bcQnKNmnIOYaTODGrKrEMyCOt3F1beHksmGkVybX8gjiHtCK
> vg_local-lv_snap_pre_sp4-cow            254  10 L--w    1    1      0
> LVM-btzX70eAWIejM6K1bcQnKNmnIOYaTODGRANlNEYz9OBICsXXWfDNtFd1kQCovks3-cow
> 3600508b1001c5037520913a9b581d78d-part3 254   4 L--w    4    1      0
> part3-mpath-3600508b1001c5037520913a9b581d78d
> vg_local-lv_snap_pre_sp4                254  11 L--w    0    1      0
> LVM-btzX70eAWIejM6K1bcQnKNmnIOYaTODGRANlNEYz9OBICsXXWfDNtFd1kQCovks3
> 3600508b1001c5037520913a9b581d78d-part2 254   3 L--w    2    1      0
> part2-mpath-3600508b1001c5037520913a9b581d78d
> 3600c0ff00012824b04af7a5201000000       254   1 L--w    3    1      0
> mpath-3600c0ff00012824b04af7a5201000000
> 3600508b1001c5037520913a9b581d78d-part1 254   2 L--w    0    1      0
> part1-mpath-3600508b1001c5037520913a9b581d78d
> 3600c0ff00012824b04af7a5201000000-part3 254   7 L--w    0    1      0
> part3-mpath-3600c0ff00012824b04af7a5201000000
> 3600c0ff00012824b04af7a5201000000-part2 254   6 L--w    0    1      0
> part2-mpath-3600c0ff00012824b04af7a5201000000
> vg_local-lv_tmp                         254  12 L--w    1    1      0
> LVM-btzX70eAWIejM6K1bcQnKNmnIOYaTODGjcHjj26T647y1Lh468NGS5GysMiYeG7v
> vg_local-lv_root                        254   9 L--w    1    1      0
> LVM-btzX70eAWIejM6K1bcQnKNmnIOYaTODGt79QZ80zYmQrwddi2BBMObpN1gLssjEF
> 3600c0ff00012824b04af7a5201000000-part1 254   5 L--w    0    1      0
> part1-mpath-3600c0ff00012824b04af7a5201000000
> 3600508b1001c5037520913a9b581d78d       254   0 L--w    3    1      0
> mpath-3600508b1001c5037520913a9b581d78d
> 
> ha-idg-2:~ # lvs
>    Logging initialised at Thu Apr 11 19:17:58 2019
>    Set umask from 0022 to 0077
> lvs  connect() failed on local socket: No such file or directory
> lvs  Internal cluster locking initialisation failed.
> lvs  WARNING: Falling back to local file-based locking.
> lvs  Volume Groups with the clustered attribute will be inaccessible.
> lvs  Skipping clustered volume group vg_san
> lvs  LV              VG       Attr       LSize   Pool Origin  Data%  Meta%  Move
> Log Cpy%Sync Convert
> lvs  lv_root         vg_local owi-aos--- 100.00g
> lvs  lv_snap_pre_sp4 vg_local swi-a-s---  50.00g      lv_root 15.12
> lvs  lv_tmp          vg_local -wi-ao----  40.00g
> lvs  lv_var          vg_local -wi-ao----  40.00g
> 
> output from dmesg:
> [  309.203692] device-mapper: ioctl: can't change device type after initial
> table load.
> 
> ha-idg-2:~ # dmsetup table vg_local-lv_root
> 0 209715200 snapshot-origin 254:8
> 
> AFAIK it seems that 254:9 (lv_root) is still snapshot-origin and lvremove
> can't change it to linear, right ?
> 
> Bernd
> 

Hi,

i finally managed it. I did a vgcfgrestore to the state just before creating the snapshot.
Afterwards a reboot and now everything is fine.
But how could that happen or what can i do to avoid that ?
I had several snapshots. Do i have to follow an order to delete them ?
I think they are all independent, aren't they ?

Bernd
 

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