Mention libnsl for OL8

INSTALL.md

@@ -112,8 +112,9 @@ guaranteed to be available or usable in your environment.
       architecture.
 
       Instant Client on Windows requires an appropriate [Visual Studio
-      Redistributable](#winredists).  On Linux, the `libaio`
-      (sometimes called `libaio1`) package is needed.
+      Redistributable](#winredists).  On Linux, the `libaio` (sometimes called
+      `libaio1`) package is needed.  On recent Linux versions, such as Oracle
+      Linux 8, you may also need to install the `libnsl` package.
 
     - Alternatively use the Oracle Client libraries already available
       in `$ORACLE_HOME/lib` from a locally installed database such as
@@ -293,7 +294,8 @@ install the Basic package after enabling the ol7_x86_64_instantclient or
 ol6_x86_64_instantclient channel, depending on your version of Linux.
 
 Using any of these methods will install the required `libaio` package, if it is
-not already present.
+not already present.  On recent Linux versions, such as Oracle Linux 8, you may
+also need to manually install the `libnsl` package.
 
 For Instant Client 19 RPMs, the system library search path is automatically
 configured during installation.  For older versions, if there is no other Oracle
@@ -427,7 +429,8 @@ unzip instantclient-basic-linuxx64.zip
 You will need the operating system `libaio` package installed.  On some
 platforms the package is called `libaio1`.  Run a command like `yum install -y
 libaio` or `apt-get install -y libaio1`, depending on your Linux distribution
-package manager.
+package manager.  On recent Linux versions, such as Oracle Linux 8, you may also
+need to install the `libnsl` package.
 
 If there is no other Oracle software on the machine that will be impacted, then
 permanently add Instant Client to the run-time link path.  For example, if the
@@ -1504,6 +1507,9 @@ install Instant Client.  Three methods are shown below.
         rm -rf /var/cache/yum
    ```
 
+   On recent Linux versions, such as Oracle Linux 8, you may also need to
+   manually install the `libnsl` package.
+
 2. Automatically downloading an Instant Client ZIP file
 
    You can automatically download an Instant Client ZIP file during image
@@ -1534,6 +1540,9 @@ install Instant Client.  Three methods are shown below.
        echo /opt/oracle/instantclient* > /etc/ld.so.conf.d/oracle-instantclient.conf && ldconfig
    ```
 
+   On recent Linux versions, such as Oracle Linux 8, you may also need to
+   install the `libnsl` package.
+
 3. Copying Instant Client zip files from the host
 
    To avoid the cost of repeated network traffic, you may prefer to download the
@@ -1571,6 +1580,9 @@ install Instant Client.  Three methods are shown below.
    RUN apt-get update && apt-get install -y libaio1
    ```
 
+   On recent Linux versions, such as Oracle Linux 8, you may also need to
+   install the `libnsl` package.
+
 #### Installing node-oracledb and your application
 
 Include node-oracledb as a normal dependency in your application `package.json` file: