Re: btrfs: convert metadata from raid5 to raid1

Menion
2020-02-18T08:35:13Z

Hello again

Task completed, I see in three occurrence of this event:

[518366.156963] INFO: task btrfs-cleaner:1034 blocked for more than 120 seconds.
[518366.156989] Not tainted 5.5.3-050503-generic #202002110832
[518366.157024] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[518366.157044] btrfs-cleaner D 0 1034 2 0x80004000
[518366.157054] Call Trace:
[518366.157082] __schedule+0x2d8/0x760
[518366.157094] schedule+0x55/0xc0
[518366.157105] schedule_preempt_disabled+0xe/0x10
[518366.157113] __mutex_lock.isra.0+0x182/0x4f0
[518366.157125] __mutex_lock_slowpath+0x13/0x20
[518366.157132] mutex_lock+0x2e/0x40
[518366.157261] btrfs_delete_unused_bgs+0xc0/0x560 [btrfs]
[518366.157322] ? __wake_up+0x13/0x20
[518366.157424] cleaner_kthread+0x124/0x130 [btrfs]
[518366.157437] kthread+0x104/0x140
[518366.157531] ? kzalloc.constprop.0+0x40/0x40 [btrfs]
[518366.157565] ? kthread_park+0x90/0x90
[518366.157575] ret_from_fork+0x35/0x40

and

[518486.984177] INFO: task btrfs-cleaner:1034 blocked for more than 241 seconds.
[518486.984204] Not tainted 5.5.3-050503-generic #202002110832
[518486.984216] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[518486.984233] btrfs-cleaner D 0 1034 2 0x80004000
[518486.984243] Call Trace:
[518486.984271] __schedule+0x2d8/0x760
[518486.984284] schedule+0x55/0xc0
[518486.984295] schedule_preempt_disabled+0xe/0x10
[518486.984305] __mutex_lock.isra.0+0x182/0x4f0
[518486.984319] __mutex_lock_slowpath+0x13/0x20
[518486.984326] mutex_lock+0x2e/0x40
[518486.984451] btrfs_delete_unused_bgs+0xc0/0x560 [btrfs]
[518486.984464] ? __wake_up+0x13/0x20
[518486.984562] cleaner_kthread+0x124/0x130 [btrfs]
[518486.984573] kthread+0x104/0x140
[518486.984666] ? kzalloc.constprop.0+0x40/0x40 [btrfs]
[518486.984675] ? kthread_park+0x90/0x90
[518486.984686] ret_from_fork+0x35/0x40

and

[518728.646379] INFO: task btrfs-cleaner:1034 blocked for more than 120 seconds.
[518728.646413] Not tainted 5.5.3-050503-generic #202002110832
[518728.646428] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[518728.646447] btrfs-cleaner D 0 1034 2 0x80004000
[518728.646460] Call Trace:
[518728.646494] __schedule+0x2d8/0x760
[518728.646508] schedule+0x55/0xc0
[518728.646522] schedule_preempt_disabled+0xe/0x10
[518728.646534] __mutex_lock.isra.0+0x182/0x4f0
[518728.646550] __mutex_lock_slowpath+0x13/0x20
[518728.646559] mutex_lock+0x2e/0x40
[518728.646719] btrfs_delete_unused_bgs+0xc0/0x560 [btrfs]
[518728.646735] ? __wake_up+0x13/0x20
[518728.646859] cleaner_kthread+0x124/0x130 [btrfs]
[518728.646875] kthread+0x104/0x140
[518728.647019] ? kzalloc.constprop.0+0x40/0x40 [btrfs]
[518728.647031] ? kthread_park+0x90/0x90
[518728.647045] ret_from_fork+0x35/0x40

Is it a kind of normal?
Thanks, bye

Il giorno lun 17 feb 2020 alle ore 15:12 Menion <menion@gmail.com> ha scritto:
>
> ok thanks
> I have launched it (in a tmux session), after 5 minutes the command
> did not return yet, but dmesg and btrfs balance status
> /array/mount/point report it in progress (0%).
> Is it normal?
>
> Il giorno lun 17 feb 2020 alle ore 14:55 Swâmi Petaramesh
> <swami@petaramesh.org> ha scritto:
> >
> > On 2020-02-17 14:50, Menion wrote:
> > > Is it ok to run it on a mounted filesystem with concurrent read and
> > > write operations?
> >
> > Yes. Please check man btrfs-balance.
> >
> > All such BTRFS operations are to be run on live, mounted filesystems.
> >
> > Performance will suffer and it might be long though.
> >
> > > Also, since the number of HDD is 5, how this "raid1" scheme is deployed?
> >
> > BTRFS will manage storing 2 copies of every metadata block on 2
> > different disks, and will choose how by itself.
> >
> > ॐ
> >
> > --
> > Swâmi Petaramesh <swami@petaramesh.org> PGP 9076E32E
> >