- **Speed:** The journal enables the Ceph OSD Daemon to commit small writes
quickly. Ceph writes small, random i/o to the journal sequentially, which
- tends to speed up bursty workloads by allowing the backing filesystem more
+ tends to speed up bursty workloads by allowing the backing file system more
time to coalesce writes. The Ceph OSD Daemon's journal, however, can lead
to spiky performance with short spurts of high-speed writes followed by
- periods without any write progress as the filesystem catches up to the
+ periods without any write progress as the file system catches up to the
journal.
-- **Consistency:** Ceph OSD Daemons require a filesystem interface that
+- **Consistency:** Ceph OSD Daemons require a file system interface that
guarantees atomic compound operations. Ceph OSD Daemons write a description
- of the operation to the journal and apply the operation to the filesystem.
+ of the operation to the journal and apply the operation to the file system.
This enables atomic updates to an object (for example, placement group
metadata). Every few seconds--between ``filestore max sync interval`` and
``filestore min sync interval``--the Ceph OSD Daemon stops writes and
- synchronizes the journal with the filesystem, allowing Ceph OSD Daemons to
+ synchronizes the journal with the file system, allowing Ceph OSD Daemons to
trim operations from the journal and reuse the space. On failure, Ceph
OSD Daemons replay the journal starting after the last synchronization
operation.
projects / ceph.git / blobdiff