partprobe command was missing in the document which is required to update the kernel that the disk has been partition.

Author: kailashmsft

articles/virtual-machines/linux/add-disk.md

@@ -118,6 +118,8 @@ The partition table has been altered!
 Calling ioctl() to re-read partition table.
 Syncing disks.
 ```
+Use the below command to update the kernel
+partprobe 
 
 Now, write a file system to the partition with the `mkfs` command. Specify your filesystem type and the device name. The following example creates an *ext4* filesystem on the */dev/sdc1* partition that was created in the preceding steps:
 
@@ -231,4 +233,4 @@ There are two ways to enable TRIM support in your Linux VM. As usual, consult yo
 ## Next steps
 
 * To ensure your Linux VM is configured correctly, review the [Optimize your Linux machine performance](optimization.md) recommendations.
-* Expand your storage capacity by adding additional disks and [configure RAID](configure-raid.md) for additional performance.
+* Expand your storage capacity by adding additional disks and [configure RAID](configure-raid.md) for additional performance.