Hi all,
I have some question related to the caching layer. I am using the latest
version of ceph: 0.94.1. I created the ceph pool with this options:
ceph osd tier add ecdata cache
ceph osd tier cache-mode cache writeback
ceph osd tier set-overlay ecdata cache
ceph osd pool set cache hit_set_type bloom
ceph osd pool set cache hit_set_count 1
ceph osd pool set cache hit_set_period 3600
ceph osd pool set cache target_max_bytes $((300*1024*1024*1024))
I checked these values were set correctly
I also checked some other parameters:
ceph osd pool get cache cache_target_dirty_ratio
cache_target_dirty_ratio: 0
ceph osd pool get cache cache_target_full_ratio
cache_target_full_ratio: 0
get cache cache_min_flush_age
cache_min_flush_age: 0
ceph osd pool get cache cache_min_evict_age
cache_min_evict_age: 0
My first question: What do these zero values mean? Is this really zero,
or some default value. I don't find defaults in the documentation.
Now a strange thing is: at first the cache pool was being filled until
it was near the target_max_bytes value of 300G. But now (about 20hours
later) I check again and there is constantly only about 2G of data in
the cache pool, so it flushes everything immediately..
Is this the result of a parameter? Can the strange behaviour of an
initial filling cache that after it started flushing the first time
keeps on flushing everything be explained?
So the cache is empty, but I get warning when I check the health:
health HEALTH_WARN
mds0: Client cephtst.cubone.os failing to respond to cache
pressure
Someone an idea what is happening here?
Thank you very much!
Kenneth
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
