Re: Btrfs hangs 3.19-10

[Duncan <1i5t5.duncan@cox.net>]

Pavel Volkov posted on Mon, 06 Apr 2015 10:40:03 +0300 as excerpted:

> On Sunday, April 5, 2015 1:04:17 PM MSK, Hugo Mills wrote:
>>    That's these, I think:
>>
>> #define BTRFS_FEATURE_INCOMPAT_BIG_METADATA     (1ULL << 5)
>> #define BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF    (1ULL << 6)
>>
>> so it's definitely -O^extref. I don't see where big_metadata comes
>> from, though. That's not a -O option. Try with -O^extref and see where
>> that gets you. (Also, don't mount the FS on a newer kernel -- it may be
>> setting big metadata automatically, although it probably shouldn't do).
> 
> By the way, is there any way to see which options are enabled on a local
> filesystem without having to try mounting it with old kernel and
> checking dmesg?

btrfs-show-super shows what flags are enabled, both numerically and 
symbolically.

At least for btrfs-progs 3.19.1, which I have installed.  I'm not sure 
how far that goes back, but I don't believe it's new functionality, so 
I'd guess 3.14 at least, but likely not back all the way to 0.19, as that 
was a very long time ago in btrfs terms.

-- 
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"Every nonfree program has a lord, a master --
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