Re: btrfs-transacti hammering the system

[Matt McKinnon <matt@techsquare.com>]

Right.  The file system is 48T, with 17T available, so we're not quite 
pushing it yet.

So far so good on the space_cache=v2 mount.  I'm surprised this isn't on 
the gotcha page in the wiki; it may end up making a world of difference 
to the users here

Thanks again,
Matt

On 01/12/17 13:24, Hans van Kranenburg wrote:
> On 12/01/2017 06:57 PM, Holger Hoffstätte wrote:
>> On 12/01/17 18:34, Matt McKinnon wrote:
>>> Thanks, I'll give space_cache=v2 a shot.
>>
>> Yes, very much recommended.
>>
>>> My mount options are: rw,relatime,space_cache,autodefrag,subvolid=5,subvol=/
>>
>> Turn autodefrag off and use noatime instead of relatime.
>>
>> Your filesystem also seems very full,
> 
> We don't know. btrfs fi df only displays allocated space. And that being
> full is good, it means not too much free space fragments everywhere.
> 
>> that's bad with every filesystem but
>> *especially* with btrfs because the allocator has to work really hard to find
>> free space for COWing. Really consider deleting stuff or adding more space.
>