This JIRA tracks a TODO in TestSaveNamespace. Currently, if, while writing the VERSION files in the storage directories, one of the directories fails, the entire operation throws IOE. This is unnecessary – instead, just that directory should be marked as failed.
This is targeted to be fixed after
HDFS-1073 is merged to trunk, since it does not ever dataloss, and would rarely occur in practice (the dir would have to fail between writing the fsimage file and writing VERSION)