[Users] ploop ext4 reserved_ratio

[Vasily Averin]

Dear Jonathan,
thank you for reporting the problem,
we did no saw such behaviour before.

In fact ploop grow should call resize2fs and probably it ignores reserved ratio setting.
You can try to run it under strace and look at details, ploop sources are public available too.

Igor (in cc:) is going to check this behaviour, I hope he will clarify the situation soon.

Thank you,
	Vasily Averin

On 7/16/19 8:15 PM, Jonathan Wright wrote:
> What seems to be happening is if you set a reserved_ratio on an image and grow the image, that ratio is maintained and will stay at that ratio.
> 
> When shrinking the image however, mke2fs.conf is referenced and that's the ratio that gets used.
> 
> Is there a reason for this behavior to be inconsistent?  I was incorrect about making new ploop images using mke2fs.conf - it seems they don't - at least not through vzctl create.  It appears to be hard coded at 5%.
> 
> On 7/16/19 11:55 AM, Jonathan Wright wrote:
>> ext4's default 5% reserved ratio is set on ploop images.  If you update /etc/mke2fs.conf and adjust this ratio to say 1%, that's used when the ploop image is created.
>>
>> This is great.
>>
>> When you then resize that image though, the stock 5% is put back in place instead of the 1% that was on the filesystem (or whatever might be set in /etc/mke2fs.conf).
>>
>> Is this intentional functionality for some reason, a bug, or something simple no one has tried before?
>>