[
https://issues.apache.org/jira/browse/HDFS-2802?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13487496#comment-13487496
]
Suresh Srinivas commented on HDFS-2802:
---------------------------------------
bq. From my quick look, this seems to clarify much of the proposed design
I am happy to hear this.
bq. It seems that since every current file which is snapshotted is represented
by an INodeFileWithLink, at some point all files which are to be snapshotted
under a sub-directory would need to be converted from an INodeFile to an
INodeFileWithLink.
When a snapshotted file is modified, the conversion to INodeFileWithLink takes
place. So if all the snapshotted files under a directory are modified post
snapshot, they will need to be converted into INodeFileWithLink. BTW We have
flexibility here and we can eliminate the need for this completely, if we
decide snapshot of file does not preserve the replication factor at the time of
snapshot - see replication factor related section for details.
> Support for RW/RO snapshots in HDFS
> -----------------------------------
>
> Key: HDFS-2802
> URL: https://issues.apache.org/jira/browse/HDFS-2802
> Project: Hadoop HDFS
> Issue Type: New Feature
> Components: data-node, name-node
> Reporter: Hari Mankude
> Assignee: Hari Mankude
> Attachments: HDFSSnapshotsDesign.pdf, snap.patch,
> snapshot-one-pager.pdf, Snapshots20121018.pdf, Snapshots20121030.pdf
>
>
> Snapshots are point in time images of parts of the filesystem or the entire
> filesystem. Snapshots can be a read-only or a read-write point in time copy
> of the filesystem. There are several use cases for snapshots in HDFS. I will
> post a detailed write-up soon with with more information.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
