Re: [ceph-users] Use trimfs on already mounted RBD image

2018-04-05 Thread Damian Dabrowski
Ok, thanks for Your reply.

2018-04-05 8:15 GMT+02:00 Wido den Hollander :

>
>
> On 04/04/2018 07:30 PM, Damian Dabrowski wrote:
> > Hello,
> >
> > I wonder if it is any way to run `trimfs` on rbd image which is
> > currently used by the KVM process? (when I don't have access to VM)
> >
> > I know that I can do this by qemu-guest-agent but not all VMs have it
> > installed.
> >
> > I can't use rbdmap too, because most images don't have distributed
> > filesystems. It's mostly ext4/xfs so I can't mount them in two places at
> > same time.
> >
> > I would be grateful for any help.
> >
>
> No, you can not. If you map and mount a filesystem twice you will
> corrupt the data on there.
>
> Same goes when you are going to fstrim, you will probably break/corrupt
> data on the system.
>
> Do not attempt it. Shut down the VM and then do the fstrim.
>
> Wido
>
> >
> > ___
> > ceph-users mailing list
> > ceph-users@lists.ceph.com
> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> >
> ___
> ceph-users mailing list
> ceph-users@lists.ceph.com
> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>
___
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com


Re: [ceph-users] Use trimfs on already mounted RBD image

2018-04-04 Thread Wido den Hollander


On 04/04/2018 07:30 PM, Damian Dabrowski wrote:
> Hello,
> 
> I wonder if it is any way to run `trimfs` on rbd image which is
> currently used by the KVM process? (when I don't have access to VM)
> 
> I know that I can do this by qemu-guest-agent but not all VMs have it
> installed.
> 
> I can't use rbdmap too, because most images don't have distributed
> filesystems. It's mostly ext4/xfs so I can't mount them in two places at
> same time.
> 
> I would be grateful for any help.
> 

No, you can not. If you map and mount a filesystem twice you will
corrupt the data on there.

Same goes when you are going to fstrim, you will probably break/corrupt
data on the system.

Do not attempt it. Shut down the VM and then do the fstrim.

Wido

> 
> ___
> ceph-users mailing list
> ceph-users@lists.ceph.com
> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> 
___
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com