[linux-lvm] Reserve space for specific thin logical volumes

[Gionatan Danti]

Il 17-09-2017 09:10 Xen ha scritto:
> Xen schreef op 17-09-2017 8:31:
> 
> 
> But if it's not active I don't see why it should be critical or why
> you should reserve space for it to be honest...

Xen, I really think that the combination of hard-threshold obtained by 
setting thin_pool_autoextend_threshold and thin_command hook for 
user-defined script should be sufficient to prevent and/or react to full 
thin pools.

I'm all for the "keep it simple" on the kernel side. After all, thinp 
maintain very high performance in spite of its CoW behavior *even when 
approaching pool fullness*, a thing which can not be automatically said 
for advanced in-kernel filesystems as BTRFS (which very low 
random-rewrite performance) and ZFS (I just recently opened a ZoL issue 
for ZVOLs with *much* lower than expected write performance, albeit the 
workaround/correction was trivial in this case).

That said, I would like to see some pre-defined scripts to easily manage 
pool fullness. For example, a script to automatically delete all 
inactive snapshots with "deleteme" or "temporary" flag. Sure, writing 
such a script is trivial for any sysadmin - but I would really like the 
standardisation such predefined scripts imply.

Regards.

-- 
Danti Gionatan
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