On Wed, Jun 23, 2021 at 3:36 PM Marc <Marc(a)f1-outsourcing.eu> wrote: It has always been the case. This is a rather fundamental issue and it is not specific to Ceph. I don't think there is a particular Ceph release or kernel version to name other than it became much harder to hit with modern kernels. I would be cautious about attributing random stalls or hangs that may be experienced for a wide variety of reasons to this co-location issue, even if moving the mount to another machine happened to help. Usually such reports lack the necessary evidence, the last one that I could confirm to be the co-location related lockup was at least a couple of years ago. Thanks, Ilya > > > > > -----Original Message----- > > Sent: Wednesday, 23 June 2021 11:25 > > Subject: *****SPAM***** [ceph-users] Re: Can not mount rbd device > > anymore > > > > On Wed, Jun 23, 2021 at 9:59 AM Matthias Ferdinand > > wrote: > > > > > > On Tue, Jun 22, 2021 at 02:36:00PM +0200, Ml Ml wrote: > > > > Hello List, > > > > > > > > oversudden i can not mount a specific rbd device anymore: > > > > > > > > root@proxmox-backup:~# rbd map backup-proxmox/cluster5 -k > > > > /etc/ceph/ceph.client.admin.keyring > > > > /dev/rbd0 > > > > > > > > root@proxmox-backup:~# mount /dev/rbd0 /mnt/backup-cluster5/ > > > > (just never times out) > > > > > > > > > Hi, > > > > > > there used to be some kernel lock issues when the kernel rbd client > > > tried to access an OSD on the same machine. Not sure if these issues > > > still exist (but I would guess so) and if you use your proxmox cluster > > > in a hyperconverged manner (nodes providing VMs and storage service at > > > the same time) you may just have been lucky that it had worked before. > > > > > > Instead of the kernel client mount you can try to export the volume as > > > an NBD device (https://docs.ceph.com/en/latest/man/8/rbd-nbd/) and > > > mounting that. rbd-nbd runs in userspace and should not have that > > > locking problem. > > > > rbd-nbd is also susceptible to locking up in such setups, likely more > > so than krbd. Don't forget that it also has a kernel component and > > there are actually more opportunities for things to go sideways/lock up > > because there is an extra daemon involved allocating some additional > > memory for each I/O request. > > > > Thanks, > > > > Ilya > > _______________________________________________ > > ceph-users mailing list -- ceph-users(a)ceph.io > > To unsubscribe send an email to ceph-users-leave(a)ceph.io