Github user revans2 commented on a diff in the pull request:
https://github.com/apache/storm/pull/2347#discussion_r141182693
--- Diff: external/storm-blobstore-migration/README.md ---
@@ -0,0 +1,87 @@
+# Blobstore Migrator
+
+## Basic Use
+-----
+
+### Build The Thing
+Use make to build a tarball with everything needed.
+```
+$ make
+```
+
+### Use The Thing
+Copy and extract the tarball
+```
+$ scp blobstore-migrator.tgz my-nimbus-host.example.com:~/
+$ ssh my-nimbus-host.example.com
+... On my-nimbus-host ...
+$ tar -xvzf blobstore-migrator.tgz
+```
+
+This will expand into a blobstore-migrator directory with all the scripts
and the jar.
+```
+$ cd blobstore-migrator
+$ ls
+blobstore-migrator-2.0.jar listHDFS.sh listLocal.sh migrate.sh
+```
+
+To run, first create a config for the cluster.
+The config must be named 'config'
+It must contain definitions for `HDFS_BLOBSTORE_DIR`,
`LOCAL_BLOBSTORE_DIR`, and `HADOOP_CLASSPATH`.
+Hadoop jars are packaged with neither storm nor this package, so they must
be installed separately.
+
+Optional configs used to configure security are: `BLOBSTORE_PRINCIPAL`,
`KEYTAB_FILE`, and `JAAS_CONF`
+
+Example:
+```
+$ cat config
+HDFS_BLOBSTORE_DIR='hdfs://some-hdfs-namenode:8080/srv/storm/my-storm-blobstore'
+LOCAL_BLOBSTORE_DIR='/srv/storm'
+HADOOP_CLASSPATH='/hadoop/share/hdfs/*:/hadoop/common/*'
+
+# My security configs:
+BLOBSTORE_PRINCIPAL='stormUser/[email protected]'
+KEYTAB_FILE='/srv/my-keytab/stormUser.kt'
+JAAS_CONF='/storm/conf/storm_jaas.conf'
+```
+
+Now you can run any of the scripts, all of which require config to exist:
+ - listHDFS.sh: lists all blobs currently in the HDFS Blobstore
+ - listLocal.sh: lists all blobs currently in the local Blobstore
+ - migrate.sh: Begins the migration process for Nimbus. (Read instructions
below first)
+
+
+#### Migrating
+##### Nimbus
+To migrate blobs from nimbus, the following steps are necessary:
+
+1. Shut down Nimbus
--- End diff --
Can we make this shut down all nimbus instances, because of HA we cannot
leave any up.
---
