On 2/14/19 4:40 AM, John Petrini wrote: > Okay that makes more sense, I didn't realize the WAL functioned in a > similar manner to filestore journals (though now that I've had another > read of Sage's blog post, New in Luminous: BlueStore, I notice he does > cover this). Is this to say that writes are acknowledged as soon as they > hit the WAL? > Depends on the size of the write. This is different for SSD and HDD, but only small writes will be ACK'ed by the WAL, larger writes need to wait on the backing device. > Also this raises another question regarding sizing. The Ceph > documentation suggests allocating as much available space as possible to > blocks.db but what about WAL? We'll have 120GB per OSD available on each > SSD. Any suggestion on how we might divvy that between the WAL and DB? > 1GB for the WAL is sufficient. Only RocksDB writes go there, there is no need to increase it. You want to give as much to the DB as possible in your situation. > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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