Hello,
Just a note: With 7+5 you will need 13 host for access your data in case one goes down.
As far as I know, EC 7+5 imply ‘erasure size 12 min_size 8’. So I need at least 8 servers access to my data, k=7, m=5, size = k+m = 12 min_size = k+1 = 8 Am I wrong?
Expected in the nexts version allow access data with the EC numbers.
I think it is still possible to set min_size = k in Nautilus but it is not recommended. Best, Yoann
-----Mensaje original----- De: Yoann Moulin <yoann.moulin@epfl.ch> Enviado el: martes, 3 de septiembre de 2019 11:28 Para: ceph-users@ceph.io Asunto: [ceph-users] Best osd scenario + ansible config?
Hello,
I am deploying a new Nautilus cluster and I would like to know what would be the best OSD's scenario config in this case :
10x 6TB Disk OSDs (data) 2x 480G SSD previously used for journal and can be used for WAL and/or DB
Is it better to put all WAL on one SSD and all DBs on the other one? Or put WAL and DB of the first 5 OSDs on the first SSD and the 5 others on the second one.
A more general question, what is the impact on an OSD if we lose the WAL? The DB? Both?
I plan to use EC 7+5 on 12 servers and I am OK if I lose one server temporarily. I have spare servers and I can easily add another one in this cluster.
To deploy this cluster, I use ceph-ansible (stable-4.0). I am not sure how to configure the playbook to use SSD and disks with LVM.
https://github.com/ceph/ceph-ansible/blob/master/docs/source/osds/scenarios. rst
Is this good?
osd_objectstore: bluestore lvm_volumes: - data: data-lv1 data_vg: data-vg1 db: db-lv1 db_vg: db-vg1 wal: wal-lv1 wal_vg: wal-vg1 - data: data-lv2 data_vg: data-vg2 db: db-lv2 db_vg: db-vg2 wal: wal-lv2 wal_vg: wal-vg2
Is it possible to let the playbook configure LVM for each disk in a mixed case? It looks like I must configure LVM before running the playbook but I am not sure if I missed something.
Is wal_vg and db_vg can be identical (on VG per SSD shared with multiple OSDs)?
Thanks for your help.
Best regards,
-- Yoann Moulin EPFL IC-IT _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
-- Yoann Moulin EPFL IC-IT