Building off a discussion earlier this month [1], how "supported" is EXT4 for OSDs? It seems that some people are getting good results with it and I'll be testing it in our environment. The other question is if the EXT4 journal is even necessary if you are using Ceph SSD journals. My thoughts are thus: Incoming I/O is written to the SSD journal. The journal then flushes to the EXT4 partition. Only after the write is completed (I understand that this is a direct sync write) does Ceph free the SSD journal entry. Doesn't this provide the same reliability as the EXT4 journal? If an OSD crashed in the middle of the write with no EXT4 journal, the file system would be repaired and then Ceph would rewrite the last transaction that didn't complete? I'm sure I'm missing something here... Thanks, [1] http://www.spinics.net/lists/ceph-users/msg20839.html ---------------- Robert LeBlanc PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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