>> >> FWIW when using rbd-mirror to migrate volumes between SATA SSD clusters, I >> found that >> >> >> rbd_mirror_journal_max_fetch_bytes: >> section: "client" >> value: "33554432" >> >> rbd_journal_max_payload_bytes: >> section: "client" >> value: “8388608" > > Indeed, that's a good tweak that applies to the primary-side librbd > client for the mirrored image for IO workloads that routinely issue > large (> than the 16KiB default), sequential writes. This was another > compromise configuration setting to reduce the potential memory > footprint of the rbd-mirror daemon.
Direct advice from you last year ;) Extrapolating for those who haven’t done much with rbd-mirror, or who find this thread in the future, these settings worked well for me migrating at most 2 active volumes at once, ones where I had no insight into client activity. YMMV. Setting these specific values when mirroring an entire pool could well be doubleplusungood. — aad _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
