improve DVC tutorial

README.md

@@ -115,7 +115,7 @@ Note: `-d` option is to set the new remote as the default one.
 dvc push
 ```
 
-### Data version management
+## Data version management
 
 1. Current data version
 ```bash
@@ -130,7 +130,16 @@ outs:
   path: datafile.dat
 ```
 
-2. Switch to a previous commit:
+Note: we can verify that the hash stored in the `data/datafile.dat.dvc` file corresponds to the actual `data/datafile.dat` file:
+```bash
+md5sum data/datafile.dat
+```
+
+```
+a0c027223a771d1bb1519e5e5aaaf82c  data/datafile.dat
+```
+
+2. Switch to a previous git commit:
 ```bash
 git log --all --graph --oneline --decorate
 ```
@@ -149,19 +158,116 @@ git log --all --graph --oneline --decorate
 git checkout c8ad6a0
 ```
 
-3. Switch to corresponding data version
+3. Verify version of data:
 
-### Tips
+```bash
+cat data/datafile.dat.dvc
+```
 
-Disable analytics reporting:
+```
+outs:
+- md5: 8c0a82ed58e6152f9b134ba8d272dd42
+  size: 102400000
+  hash: md5
+  path: datafile.dat
+```
 
-- locally to a project:
+Note: at this point, the datafile version does not correspond (discrepancy between the hash stored in the `data/datafile.dat.dvc` file and the actual `data/datafile.dat` file:
 ```bash
-dvc config core.analytics false
+md5sum data/datafile.dat
+```
+
+```
+a0c027223a771d1bb1519e5e5aaaf82c  data/datafile.dat
+```
+
+
+```bash
+md5sum data/datafile.dat
+```
+
+```
+a0c027223a771d1bb1519e5e5aaaf82c  data/datafile.dat
+```
+
+3. Switch to corresponding version of data file:
+```bash
+dvc checkout
+```
+
+```
+M       data/datafile.dat
+```
+
+4. Verify that version of data file:
+```bash
+md5sum data/datafile.dat
 ```
 
-- globally:
+```
+8c0a82ed58e6152f9b134ba8d272dd42  data/datafile.dat
+```
+
+
+## SSH remote
+
+More details here: https://dvc.org/doc/user-guide/data-management/remote-storage/ssh
+
+1. Requirements:
+```bash
+pip install dvc-ssh
+```
+
+2. Add an SSH remote to the DVC repository:
+```bash
+dvc remote add psmn_ssh ssh://gdurif@psmn-local/home/gdurif/work/dvc-testing-remote
+```
+
+3. List DVC remotes:
+```bash
+dvc remote list
+```
+
+```
+local	/home/drg/work/dev/tmp/test_data_version_control/dvc-testing-remote
+psmn_ssh	ssh://gdurif@psmn-local/home/gdurif/work/dvc-testing-remote
+```
+
+4. Record new remote in git:
 ```bash
-dvc config --global core.analytics false
+git diff
+```
+
+```
+diff --git a/.dvc/config b/.dvc/config
+index 60e9772..a1cadea 100644
+--- a/.dvc/config
++++ b/.dvc/config
+@@ -3,3 +3,5 @@
+     remote = local
+ ['remote "local"']
+     url = ../../dvc-testing-remote
++['remote "psmn_ssh"']
++    url = ssh://gdurif@psmn-local/home/gdurif/work/dvc-testing-remote
+```
+
+```bash
+git add .dvc/config
+git commit -m "new DVC remote"
+```
+
+5. Push to a given remote:
+```bash
+dvc push -r ssh_psmn
+```
+
+## Tips
+
+Disable [analytics](https://dvc.org/doc/user-guide/analytics) reporting (locally in a repository):
+```bash
+dvc config core.analytics false
+```
+
+Note: add the `--global` option for global configuration as with `git`.
 ```