On 11/8/21 12:07, Boris Behrens wrote:
Hi, we run a larger octopus s3 cluster with only rotating disks. 1.3 PiB with 177 OSDs, some with a SSD block.db and some without. We have a ton of spare 2TB disks and we just wondered if we can bring the to good use. For every 10 spinning disks we could add one 2TB SSD and we would create two partitions per OSD (130GB for block.db and 20GB for block.wal). This would leave some empty space on the SSD for waer leveling.
A 10:1 ratio looks rather high. Discussions on this list indicate this ratio normally is in the 3:1 up to 6:1 range (for high end NVMe / SSD).
The question now is: would we benefit from this? Most of the data that is written to the cluster is very large (50GB and above). This would take a lot of work into restructuring the cluster and also two other clusters. And does it make a different to have only a block.db partition or a block.db and a block.wal partition?
Does this cluster also gets a lot of reads? I wonder if using the SSD drives for S3 metadata pools would make more sense. And also be a lot less work.
Gr. Stefan _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
