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

[Zdenek Kabelac]

Dne 13.9.2017 v 10:28 Gionatan Danti napsal(a):
> Il 13-09-2017 10:15 Zdenek Kabelac ha scritto:
>> Ohh this is pretty major constrain ;)
> 
>
>> I can well imagine  LVM will let you forcible  replace such LV with
>> error target  - so instead of  thinLV  - you will have  single 'error'
>> target snapshot - which could be possibly even  auto-cleaned once the
>> volume use-count drops bellow 0  (lvmpolld/dmeventd monitoring
>> whatever...)
>>
>> (Of course - we are not solving what happens to application
>> using/running out of such error target - hopefully something not
>> completely bad....)
>>
>> This way - you get very 'powerful' weapon to be used in those 'scriplets'
>> so you can drop uneeded volumes ANYTIME you need to and reclaim its 
>> resources...
>>
> 
> This would be *really* great. I played with dm-setup remove/error target and, 
> while working, it often freezed LVM.
> An integrated forced volume removal/swith to error target would be great.
> 


Forcible remove (with some reasonable locking - so i.e. 2 processes are not 
playing with same device :)   'dmsetup remove --force' - is replacing
existing device with 'error' target (with built-in noflush)

Anyway - if you see a reproducible problem with forcible removal - it needs to 
be reported as this is a real bug then and BZ shall be opened...

Regards

Zdenek