The WAAS system consists of a set of devices called wide area application engines (WAEs) that work together to optimize TCP traffic over your network. When client and server applications attempt to communicate with each other, the network intercepts and redirects this traffic to the WAEs so that they can act on behalf of the client application and the destination server. The WAEs examine the traffic and use built-in application policies to determine whether to optimize the traffic or allow it to pass through your network unoptimized.
One of the hardware component of WAAS device is HDD and sometimes it is required to replace the HDD after failure. This document explains the reason why after replacing the single HDD in a WAE the device didn’t came online.
WAE device with sigle HDD failed. The disk replacement itself went fine and the WAE booted fine. When checking the disk status this looked fine. Looking at the "show stat con" options it was showing TDL meaning that the CIFS AO wasn't functioning properly. When entering the command "show accelerator" it showed all the CIFS, HTTP, MAPI, etc as Licensed = Yes, Configured State = Enabled however the Operational State = Shutdown. Trying to do a disk delete-data-partition followed by a reload results in failure.
Replacing a HDD
Follow these steps to replace HDD.
Enter the disk disk-name diskxx replace command in EXEC mode at the WAAS CLI on the WAE.
Verify that the disk drive diskxx is in the Defunct state by entering the show disks details command in EXEC mode. The RAID logical drive is in the Critical state at this point.
To remove the hard disk drive in either drive bay, work from inside the chassis and disconnect the SCSI cable from the hard disk drive by using your thumbs to work the cable connector out of the drive connector.
Disconnect the power cable from the hard disk drive.
Gently pull the carrier handle and slide the hard disk drive out of the drive bay.
Insert the new drive into the same slot.
Check the hard disk drive status LED to verify that the hard disk drive is operating correctly.
IF there is a single HDD in the WAE system then it is not possible to automatically rebuild the disk from the RAID and you need to do this manually. If not done so it will result in portion of the WAAS software, that should reside on the disk, missing. For this reason several services wont start on the device.