feat(zpool): Add replace_disk. Closes #25 (#67)

* Add replace_disk. Closes #25

src/zpool/mod.rs

@@ -422,7 +422,7 @@ pub trait ZpoolEngine {
     /// Add a ZIL to existing Zpool.
     ///
     /// * `name` - Name of the zpool
-    /// * `new_zil` - VDEV to use as ZIL
+    /// * `new_zil` - A VDEV to use as ZIL
     /// * `add_mode` - Disable some safety checks
     fn add_zil<N: AsRef<str>>(
         &self,
@@ -434,7 +434,7 @@ pub trait ZpoolEngine {
     /// Add a cache to existing Zpool.
     ///
     /// * `name` - Name of the zpool
-    /// * `new_cache` - Disk to use as cache
+    /// * `new_cache` - A disk to use as cache
     /// * `add_mode` - Disable some safety checks
     fn add_cache<N: AsRef<str>, D: AsRef<OsStr>>(
         &self,
@@ -446,7 +446,7 @@ pub trait ZpoolEngine {
     /// Add a spare to existing Zpool.
     ///
     /// * `name` - Name of the zpool
-    /// * `new_spare` - Disk to use as spare
+    /// * `new_spare` - A disk to use as spare
     /// * `add_mode` - Disable some safety checks
     fn add_spare<N: AsRef<str>, D: AsRef<OsStr>>(
         &self,
@@ -455,6 +455,17 @@ pub trait ZpoolEngine {
         add_mode: CreateMode,
     ) -> ZpoolResult<()>;
 
+    /// [Replace](https://docs.oracle.com/cd/E19253-01/819-5461/gazgd/index.html) a device with another.
+    ///
+    /// * `old_disk` - A disk to be replaced.
+    /// * `new_disk` - A new disk.
+    fn replace_disk<N: AsRef<str>, D: AsRef<OsStr>, O: AsRef<OsStr>>(
+        &self,
+        name: N,
+        old_disk: D,
+        new_disk: O,
+    ) -> ZpoolResult<()>;
+
     /// Remove Spare, Cache or log device
     ///
     /// * `name` - Name of the zpool

src/zpool/open3.rs

@@ -483,6 +483,26 @@ impl ZpoolEngine for ZpoolOpen3 {
         }
     }
 
+    fn replace_disk<N: AsRef<str>, D: AsRef<OsStr>, O: AsRef<OsStr>>(
+        &self,
+        name: N,
+        old_disk: D,
+        new_disk: O,
+    ) -> Result<(), ZpoolError> {
+        let mut z = self.zpool();
+        z.arg("replace");
+        z.arg(name.as_ref());
+        z.arg(old_disk.as_ref());
+        z.arg(new_disk.as_ref());
+        debug!(self.logger, "executing"; "cmd" => format_args!("{:?}", z));
+        let out = z.output()?;
+        if out.status.success() {
+            Ok(())
+        } else {
+            Err(ZpoolError::from_stderr(&out.stderr))
+        }
+    }
+
     fn remove<N: AsRef<str>, D: AsRef<OsStr>>(&self, name: N, device: D) -> ZpoolResult<()> {
         let mut z = self.zpool();
         z.arg("remove");

tests/test_zpool.rs

@@ -853,3 +853,39 @@ fn test_zpool_add_spare() {
         assert_eq!(topo_expected, z);
     });
 }
+
+#[test]
+fn test_zpool_replace_disk() {
+    use std::{thread, time};
+
+    run_test(|name| {
+        let zpool = ZpoolOpen3::default();
+        let vdev0_path = setup_vdev("/vdevs/vdev0", &Bytes::MegaBytes(64 + 10));
+        let vdev1_path = setup_vdev("/vdevs/vdev1", &Bytes::MegaBytes(64 + 10));
+        let vdev2_path = setup_vdev("/vdevs/vdev2", &Bytes::MegaBytes(64 + 10));
+        let topo = CreateZpoolRequestBuilder::default()
+            .name(name.clone())
+            .create_mode(CreateMode::Force)
+            .vdev(CreateVdevRequest::Mirror(vec![vdev0_path.clone(), vdev1_path.clone()]))
+            .build()
+            .unwrap();
+        zpool.create(topo.clone()).unwrap();
+
+        let result = zpool.replace_disk(&name, &vdev0_path, &vdev2_path);
+        assert!(result.is_ok());
+
+        let topo_expected = CreateZpoolRequestBuilder::default()
+            .name(name.clone())
+            .create_mode(CreateMode::Force)
+            .vdev(CreateVdevRequest::Mirror(vec![vdev2_path.clone(), vdev1_path.clone()]))
+            .build()
+            .unwrap();
+
+        // otherwise test _might_ fail.
+        let wait_time = time::Duration::from_secs(13);
+        thread::sleep(wait_time);
+
+        let z = zpool.status(&name).unwrap();
+        assert_eq!(topo_expected, z);
+    });
+}