path: root/doc/admin-guide/en-US
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authorSachin Pandit <>2014-09-23 07:03:11 +0530
committerVijay Bellur <>2014-09-23 10:23:56 -0700
commit6ddfdde6fb8de21c46442b4b6b15d5b6b1eff4e4 (patch)
tree7778aedd19c34c677ba16844e85595f3d7ff4fa0 /doc/admin-guide/en-US
parent5136c938dddd909ad7a998afa643dc3dcaa6233d (diff)
doc/snapshot : admin guide updation.
Change-Id: I1980bc0984f941cd415fbc754495353f561155a8 BUG: 1145069 Signed-off-by: Sachin Pandit <> Reviewed-on: Tested-by: Gluster Build System <> Reviewed-by: Vijay Bellur <>
Diffstat (limited to 'doc/admin-guide/en-US')
1 files changed, 36 insertions, 0 deletions
diff --git a/doc/admin-guide/en-US/markdown/ b/doc/admin-guide/en-US/markdown/
index 5618a4d9cdb..93be39d94d5 100644
--- a/doc/admin-guide/en-US/markdown/
+++ b/doc/admin-guide/en-US/markdown/
@@ -14,11 +14,47 @@ pre-requisites:
* Each brick should be on an independent thinly provisioned LVM.
* Brick LVM should not contain any other data other than brick.
* None of the brick should be on a thick LVM.
+* gluster version should be 3.6 and above.
Details of how to create thin volume can be found at the following link.
+Few features of snapshot are:
+**Crash Consistency**
+when a snapshot is taken at a particular point-in-time, it is made sure that
+the taken snapshot is crash consistent. when the taken snapshot is restored,
+then the data is identical as it was at the time of taking a snapshot.
+**Online Snapshot**
+When the snapshot is being taken the file system and its associated data
+continue to be available for the clients.
+**Quorum Based**
+The quorum feature ensures that the volume is in good condition while the bricks
+are down. Quorum is not met if any bricks are down in a n-way replication where
+n <= 2. Quorum is met when m bricks are up, where m >= (n/2 + 1) where n is odd,
+and m >= n/2 and first brick is up where n is even. snapshot creation fails
+if quorum is not met.
+During snapshot creation some of the fops are blocked to guarantee crash
+consistency. There is a default time-out of 2 minutes, if snapshot creation
+is not complete within that span then fops are unbarried. If unbarrier happens
+before the snapshot creation is complete then the snapshot creation operation
+fails. This to ensure that the snapshot is in a consistent state.
Snapshot Management