Re: mount hangs after disk crash (RAID-1)

[Tomasz Chmielewski <tch@virtall.com>]

> > One disk in RAID-1 crashed, so powered off, changed disk, powered
> > on, trying to mount degraded.
> > 
> > Unfortunately it hangs (running 3.14.4).
> > 
> > # mount -o degraded,compress=lzo,noatime /dev/sdb4 /home (...never
> > returns...)
> 
> 1) Just to be sure, btrfs raid1, not btrfs on md/raid1 or the like, 
> correct?

Correct, it's btrfs raid1.


> 2) Btrfs raid1 for both data and metadata, correct?

raid1 for both data and metadata.


> 3) How many devices in the btrfs raid1?

There were 2 devices.

 
> 4) Did you try mounting read-only?

Tried also mounting with nospace_cache, recover, ro, but all hang in a
similar way.

 
> Note that unlike md/raid1, btrfs raid1 won't mount writable with only
> a single device.  You must have at least two devices to mount
> writable, tho a formerly two-device raid1 with a device missing
> should mount read-only.

That's not entirely correct - it will mount with -o degraded option.

However it hangs here...


-- 
Tomasz Chmielewski
http://wpkg.org