XS Oracle 2009 The Reflink Operation In Ocfs2

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The Linux Foundation

Joel Becker & Tao Ma: REFLINK Operation in ocfs2

Technologie Business

The REFLINK Operation in
OCFS2

Joel Becker
Tao Ma
Oracle

Problem

Virtual Machines want:
Snapshots
Clones
Space savings

The REFLINK Operation

int reflink(const char *oldpath,
const char *newpath);

reflink()has the same calling semantics as link
(2), but creates a new file that shares all the data
extents of the source file.

Using REFLINK

Snapshots:
# umask 333 && reflink host1.img
host1.img.snap

Restore:
# unlink host1.img
# reflink host1.img.snap host1.img
Clones:
# reflink os-base.img host1.img
# create-vm --name host1 host1.img

Discuss!

Questions?

Thank you for having us here.
Joel & Tao

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