Querying for disk health

The appliance can be queried to report disk health. You can use the response to this query to configure load balancers or other traffic redirection devices to redirect traffic accordingly. This functionality is especially important in acceleration deployments in which a failed disk can lead to proxied requests and increased load on the accelerated servers.

To query the appliance for disk health, send a request to the following URL:

http://cache_hostname:3132/cache_manager/disk_status

The appliance will send one of the following disk status messages in response to the preceding HTTP request:

If the appliance is handling requests normally, it will issue the following status message:
```
HTTP/1.0 200 OK
```
```
X-Cache-Status: DISK OK
```
If the appliance cannot keep up with incoming requests, it will send the following status message:
```
HTTP/1.0 500 ERROR
```
```
X-Cache-Status: DISK BUSY
```

Changing the disk busy threshold

The default value of the disk busy threshold is 10. The default value of 10 indicates that 10 percent of misses were proxied to back-end servers in the last five minutes because the disk could not keep up with incoming requests.

Use the config.http.disk_busy_thr option to change the disk busy threshold. For example:

set cofig.http.disk_busy_thr //