Re: [ceph-users] I/O stalls when doing fstrim on large RBD

cific to the newer librbd? > > Thanks again, > Brendan > > > From: Jason Dillaman [jdill...@redhat.com] > Sent: Monday, November 27, 2017 5:49 PM > To: Brendan Moloney > Cc: ceph-users@lists.ceph.com > Subject: Re: [ceph-users]

Re: [ceph-users] I/O stalls when doing fstrim on large RBD

, 2017 5:49 PM To: Brendan Moloney Cc: ceph-users@lists.ceph.com Subject: Re: [ceph-users] I/O stalls when doing fstrim on large RBD My only possible suggestion would be to try a Luminous librbd client and enable the object-map feature on the image. When the object map is enabled, librbd will optimize

Re: [ceph-users] I/O stalls when doing fstrim on large RBD

My only possible suggestion would be to try a Luminous librbd client and enable the object-map feature on the image. When the object map is enabled, librbd will optimize away all the no-op discard requests. If that doesn't work, it could be an issue in the OS / controller interaction. On Mon, Nov

Re: [ceph-users] I/O stalls when doing fstrim on large RBD

Hi, Anyone have input on this? I am surprised there are not more people running into this issue. I guess most people don't have multi-TB RBD images? I think ext4 might also fair better since it does keep track of blocks that have been discarded in the past and not modified so that they

Re: [ceph-users] I/O stalls when doing fstrim on large RBD

man [jdill...@redhat.com] Sent: Saturday, November 18, 2017 5:08 AM To: Brendan Moloney Cc: ceph-users@lists.ceph.com Subject: Re: [ceph-users] I/O stalls when doing fstrim on large RBD Can you capture a blktrace while perform fstrim to record the discard operations? A 1TB trim extent would caus

Re: [ceph-users] I/O stalls when doing fstrim on large RBD

Can you capture a blktrace while perform fstrim to record the discard operations? A 1TB trim extent would cause a huge impact since it would translate to approximately 262K IO requests to the OSDs (assuming 4MB backing files). On Fri, Nov 17, 2017 at 6:19 PM, Brendan Moloney

[ceph-users] I/O stalls when doing fstrim on large RBD

Hi, I guess this isn't strictly about Ceph, but I feel like other folks here must have run into the same issues. I am trying to keep my thinly provisioned RBD volumes thin. I use virtio-scsi to attach the RBD volumes to my VMs with the "discard=unmap" option. The RBD is formatted as XFS and