On 2017-02-23 19:54, Qu Wenruo wrote:
At 02/23/2017 06:51 PM, Christian Theune wrote:
Hi,
not sure whether it’s possible, but we tried space_cache=v2 and
obviously after working fine in staging it broke in production. Or
rather: we upgraded from 4.4 to 4.9 and enabled the space_cache. Our
production volume is around 50TiB usable (underlying HW Raid 6).
The machine crashes silently every 15 hours or so and takes _ages_ to
reboot. It current is stuck trying to mount the local filesystems and
I guess btrfs is doing something, but I don’t have shell access yet.
I’m wondering whether we can downgrade by booting back into 4.4 or
will this break things even further? (We’ve had some unpleasant
surprises with FS’ in the last months, so I thought I’d rather ask.)
You could use "btrfs check --clear-space-cache" to completely cleanup
space cache. Both v1(free space cache, file based) or v2(free space
tree) are supported.
And specially for v2 space cache (space cache tree), "btrfs check
--clear-space-cache" will also clear the ro_compat flag, so older kernel
should mount the fs without problem.
That's really good to know. I hadn't remembered that using mount
options didn't clear the flag.
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
