traffic_cache_tool is designed to interact with the Traffic Server cache both for inspection and modification. It uses a nested command keyword style for specifying operations. There are some global options that apply to all commands. These should be specified before any command. These can be abbreviated to any unique initial substring (e.g. “–sp” for “–span”).


Prints a brief usage message along with the current command hierarchy.


Specify the span (storage) configuration. This can be a device, a cache directory, or a configuration file in the formof storage.config. In the latter case all devices listed in the configuration file become active.


Specify the volume configuration file in the format of volume.config. This is important primarily for allocation operations where having the volume configuration is needed in order to properly allocate storage in spans to specific volumes.


Enable writing to storage devices. If this flag is not present then all storage will be opened read only and no operation will write to any storage device. This makes “dry run” the default and actual changes require specifying this flag.


Specific the average object size in bytes. This is used in various computations. It is identical to proxy.config.cache.min_average_object_size.


Specify the input file or disk.



Search the spans for stripe data and display it. This is potentially slow as large sections of the disk may need to be read to find the stripe headers.

Print internal stripe metadata.

Clear all the spans by writing updated span headers.

Clears an specific span and it’s stripes. The span to be cleared is specified via --device

Perform diagnostics on the stripe directories.

Full check of the directories.
Validate the directory free lists.
Validate the bucket chains in the directories.
Compute storage allocation to stripes based on the volume configuration and print it.

Allocate storage to stripes, updating the span and stripe headers.

Allocate only free (unused) storage to volumes, updating span and stripe headers as needed.
Initializes an uninitialized span and creates stripes on that span according to the volume and storage configuration The span to be initialized can be passed via --input
Determines the stripe in disk cache where the content corresponding to the provided URL may be cached. This command takes an input file which lists all the urls for which the stripe assignment needs to be determined.


List the basic span data.:

traffic_cache_tool --spans=/usr/local/etc/trafficserver/storage.config list

Allocate unused storage space.:

traffic_cache_tool \
   --spans=/usr/local/etc/trafficserver/storage.config \
   --volumes=/usr/local/etc/trafficserver/volume.config \
   alloc free

Clear all spans.:

traffic_cache_tool \
 --spans=/usr/local/etc/trafficserver/storage.config \
 --volumes=/usr/local/etc/trafficserver/volume.config \

Clear a single span.:

traffic_cache_tool \
--span /opt/etc/trafficserver/storage.config \
--volume /opt/etc/trafficserver/volume.config \
clear span --device "/dev/sdb3" --write

Initialize a new span.:

traffic_cache_tool \
--span /opt/etc/trafficserver/storage.config \
--volume /opt/etc/trafficserver/volume.config \
init --input "/dev/sdb3" --write

Find Stripe Assignment.:

traffic_cache_tool \
--span /opt/etc/trafficserver/storage.config \
--volume /opt/etc/trafficserver/volume.config \
init --input "/home/user/urls.txt"

See also

storage.config(5) volume.config(5),