Hi Andy

On Sat, Mar 16, 2024 at 8:58 PM Andy Seaborne <[email protected]> wrote:

>
>
> On 12/03/2024 13:17, Gaspar Bartalus wrote:
> > On Mon, Mar 11, 2024 at 6:28 PM Andy Seaborne<[email protected]>  wrote:
> >>
> >> On 11/03/2024 14:35, Gaspar Bartalus wrote:
> >>> Hi Andy,
> >>>
> >>> On Fri, Mar 8, 2024 at 4:41 PM Andy Seaborne<[email protected]>  wrote:
> >>>
> >>>>
> >>>> On 08/03/2024 10:40, Gaspar Bartalus wrote:
> >>>>> Hi,
> >>>>>
> >>>>> Thanks for the responses.
> >>>>>
> >>>>> We were actually curious if you'd have some explanation for the
> >>>>> linear increase in the storage, and why we are seeing differences
> >> between
> >>>>> the actual size of our dataset and the size it uses on disk. (Changes
> >>>>> between `df -h` and `du -lh`)?
> >>>> Linear increase between compactions or across compactions? The latter
> >>>> sounds like the previous version hasn't been deleted.
> >>>>
> >>> Across compactions, increasing linearly over several days, with
> >> compactions
> >>> running every day. The compaction is used with the "deleteOld"
> parameter,
> >>> and there is only one Data- folder in the volume, so I assume
> compaction
> >>> itself works as expected.
>
> >> Strange - I can't explain that. Could you check that there is only one
> >> Data-NNNN directory inside the database directory?
> >>
> > Yes, there is surely just one Data-NNNN folder in the database directory.
> >
> >> What's the disk storage setup? e.g filesystem type.
> >>
> > We have an Azure disk of type Standard SSD LRS with a filesystem of type
> > Ext4.
>
> Hi Gaspar,
>
> I still can't explain what your seeing I'm afraid.
>
> Can we get some more details?
>
> When the server has Data-N -- how big (as reported by 'du -sh') is that
> directory and how big is the whole directory for the database. They
> should be nearly equal.


> When a compaction is done, and the server is at Data-(N+1), what are the
> sizes of Data-(N+1) and the database directory?
>

What we see with respect to compaction is usually the following:
- We start with the Data-N folder of ~210MB
- After compaction we have a Data-(N+1) folder of size ~185MB, the old
Data-N being deleted.
- The sizes of the database directory and the Data-* directory are equal.

However when we check with df -h we sometimes see that volume usage is not
dropping, but on the contrary, it goes up ~140MB after each compaction.

>
> Does stop/starting the server change those numbers?
>

Yes, then we start fresh where du -sh and df -h return the same numbers.

>
>      Andy
>

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