When restore, I got follow exception:　
[ INFO] Restore started at [10/15/12 02:58:15]
[ INFO] Working into /var/lib/jenkins_restore directory
[ INFO] Uncompressing archive file...
org.jvnet.hudson.plugins.backup.utils.compress.ArchiverException: Unable to created directory /var/lib/jenkins_restore
at org.jvnet.hudson.plugins.backup.utils.compress.AbstractUnArchiver.unArchive(AbstractUnArchiver.java:52)
at org.jvnet.hudson.plugins.backup.utils.RestoreTask.run(RestoreTask.java:94)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.io.IOException: Unable to create directory /var/lib/jenkins_restore
at org.apache.commons.io.FileUtils.forceMkdir(FileUtils.java:1488)
at org.jvnet.hudson.plugins.backup.utils.compress.AbstractUnArchiver.unArchive(AbstractUnArchiver.java:48)
... 2 more
[ERROR] Error uncompressing archive : Unable to created directory /var/lib/jenkins_restore