Re: MDS cache always increasing

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Got it.

However, to narrow down the issue, I suggest that you test whether it
still exists after the following changes:

1. Reduce max_mds to 1.
2. Do not reduce max_mds to 1, but migrate all clients from a direct
CephFS mount to NFS.

On Sat, Aug 31, 2024 at 2:55 PM Sake Ceph <ceph@xxxxxxxxxxx> wrote:
>
> I was talking about the hosts where the MDS containers are running on. The clients are all RHEL 9.
>
> Kind regards,
> Sake
>
> > Op 31-08-2024 08:34 CEST schreef Alexander Patrakov <patrakov@xxxxxxxxx>:
> >
> >
> > Hello Sake,
> >
> > The combination of two active MDSs and RHEL8 does ring a bell, and I
> > have seen this with Quincy, too. However, what's relevant is the
> > kernel version on the clients. If they run the default 4.18.x kernel
> > from RHEL8, please either upgrade to the mainline kernel or decrease
> > max_mds to 1. If they run a modern kernel, then it is something I do
> > not know about.
> >
> > On Sat, Aug 31, 2024 at 1:21 PM Sake Ceph <ceph@xxxxxxxxxxx> wrote:
> > >
> > > @Anthony: it's a small virtualized cluster and indeed SWAP shouldn't be used, but this doesn't change the problem.
> > >
> > > @Alexander: the problem is in the active nodes, the standby replay don't have issues anymore.
> > >
> > > Last night's backup run increased the memory usage to 86% when rsync was running for app2. It dropped to 77,8% when it was done. When the rsync for app4 was running it increased to 84% and dropping to 80%. After a few hours it's now settled on 82%.
> > > It looks to me the MDS server is caching something forever while it isn't being used..
> > >
> > > The underlying host is running on RHEL 8. Upgrade to RHEL 9 is planned, but hit some issues with automatically upgrading hosts.
> > >
> > > Kind regards,
> > > Sake
> > > _______________________________________________
> > > ceph-users mailing list -- ceph-users@xxxxxxx
> > > To unsubscribe send an email to ceph-users-leave@xxxxxxx
> >
> >
> >
> > --
> > Alexander Patrakov



-- 
Alexander Patrakov
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