[PATCH pve-docs] zfs: Add paragraph on adding hot-spares

[Jonas Theisen <j.theisen@proxmox.com>]

Add command to add hot spare to existing ZFS pool since it came up
in a Proxmox VE Training.

Reference https://docs.oracle.com/cd/E19253-01/819-5461/gcvcw/index.html

Signed-off-by: Jonas Theisen <j.theisen@proxmox.com>
---
 local-zfs.adoc | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/local-zfs.adoc b/local-zfs.adoc
index cdc17a4..029f628 100644
--- a/local-zfs.adoc
+++ b/local-zfs.adoc
@@ -504,6 +504,17 @@ You can also add ZIL and cache separately.
 # zpool add <pool> log <log-device>
 ----
 
+[[sysadmin_zfs_add_hot_spare]]
+Adding a hot spare drive to an existing pool
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+ZFS supports hot spare drives which allow the system to automatically replace
+a failed disk with the spare without manual intervention.
+
+.Add a hot spare to an existing pool
+----
+# zpool add <pool> spare <spare-device>
+----
 
 [[sysadmin_zfs_change_failed_dev]]
 Changing a failed device
-- 
2.47.3