Primarily, there are two main configuration-managing commands, each having multiple subcommands and sub-subcommands:

  1. ais config - show and update configuration
  2. ais show config - show configuration

As always, the subcommands of the ais config and, respectively, ais show config will reveal themselves as completions (upon <TAB-TAB>).

In brief:

$ ais config --help
   ais config - configure AIS cluster and individual nodes (in the cluster); configure CLI (tool)

   ais config command [command options] [arguments...]

   show     show CLI, cluster, or node configurations (nodes inherit cluster and have local)
   cluster  configure AIS cluster
   node     configure AIS node
   reset    reset (cluster | node | CLI) configuration to system defaults
   cli      display and change AIS CLI configuration

   --help, -h  show help

As always, ais config show is an alias for ais show config - both can be used interchangeably.

Here’s a couple quick usage examples:

Example: show config, update config

# show `ais config` subcommands:
$ ais config <TAB-TAB>
cli    cluster    node    reset    show

# select `cluster` configuration and see usage and options
$ ais config cluster --help

# show the entire cluster configuration in JSON
$ ais config cluster --json

# show one selected section (e.g., checksum) from the cluster config
$ ais config cluster checksum

# update one value (e.g., checksum type)
$ ais config cluster checksum=md5

# using JSON-formatted values, update backend configuration;
# for supported backend providers, see docs/
$ ais config cluster backend.conf='{"gcp":{}, "aws":{}}'

# e.g., to remove all backends, run:
# ais config cluster backend.conf='{}'

Notice single quotes above. Single or double quotes are required when the value contains spaces and/or wildcards. But single quotes, in particular, are strongly recommended when the value itself contains double quotes.

Example: show specific config section (flat and JSON)

$ ais show cluster config ec
PROPERTY                 VALUE
ec.objsize_limit         262144
ec.compression           never
ec.bundle_multiplier     2
ec.data_slices           1
ec.parity_slices         1
ec.enabled               false
ec.disk_only             false

# same in JSON:

$ ais show config cluster ec --json

    "ec": {
        "objsize_limit": 262144,
        "compression": "never",
        "bundle_multiplier": 2,
        "data_slices": 1,
        "parity_slices": 1,
        "enabled": false,
        "disk_only": false

Further, as far as configuration, AIS supports inheritance and local override.

Here’s how it works:

At any point in time there is a single, protected and replicated, version of the cluster configuration. When a new cluster gets deployed, all clustered nodes inherit the same (initial) version - identical default values.

Subsequently, when a new node joins cluster it will also receive the current version of the cluster configuration.

On the other hand, it is possible at any point in time to select any node and override (any selected) inherited value - the value inherited by the node with its replica of the cluster config.

Note, however: if and when the corresponding value changes on the cluster level, the node’s override will take precedence - the specific update won’t apply (to this node).

In other words, overriding inherited (cluster) configuration on the node level breaks the future inheritance.

Use ais config reset to remove all previous overrides.

Finally, note that all configuration updates are, by default, persistent. Use the --transient flag to make them transient - i.e., in memory only, i.e., not persisting across reboots.

See also:

Table of Contents

Show configuration

The command ais show config is structured as follows.

# 1. Select to show: CLI config, cluster config, or the config of any of the clustered nodes, e.g.:

$ ais show config <TAB-TAB>
cli           cluster       p[kdQp8080]   t[NBzt8081]

Notice here (and everywhere) that target nodes have t prefix, while AIS gateways (aka proxies) start with p.

# 2. For the cluster config, select a named section, or simply press Enter. Following
# is the complete list of configuration sections resulting from pressing <TAB-TAB>:

$ ais show config cluster
auth               disk               features           lru                proxy              timeout
backend            distributed_sort   fshc               memsys             rebalance          transport
checksum           downloader         keepalivetracker   mirror             resilver           uuid
client             ec                 lastupdate_time    net                space              versioning
config_version     log                periodic           tcb                write_policy
# 3. Tip: help is available at any point. For instance, as stated above, you could select a section.
# But you could also run `ais show config cluster` with no section selected,
# with or without `--json` option to format the output:

$ ais show config cluster --help
   ais show config - show CLI, cluster, or node configurations (nodes inherit cluster and have local)

   ais show config [command options] cli | cluster [CONFIG SECTION OR PREFIX] |
      NODE_ID [ cluster | local | all [CONFIG SECTION OR PREFIX ] ]

   --json, -j  json input/output
   --help, -h  show help
# 4. Finally, for any specific node you can show its inherited config (where some of the values *may* be overridden) and its local one:

$ ais show config t[NBzt8081]
inherited   local

ais show config

As stated above, the command further splits as follows:

ais show config cluster or ais show config cli or ais show config [NODE_ID]

Node configuration consists of two parts:

  • global cluster configuration which is the same across the cluster
  • local daemon configuration which overrides the global one.

Cluster configuration

ais show cluster config [CONFIG_PREFIX]

Display the cluster configuration. If CONFIG_PREFIX is given, only that configurations matching the prefix will be shown.


Flag Type Description Default
--json, -j bool Output in JSON format false

Node configuration

ais show config NODE_ID [CONFIG_PREFIX]

Display the actual daemon configuration. If CONFIG_PREFIX is given, only the configurations matching the prefix will be shown. The output includes extra column with global values. Some values in the column have special meaning:

  • - - the local and global values are the same, the option is not overridden
  • N/A - the option is local-only and does not exist in global config


Flag Type Description Default
--json, -j bool Output in JSON format false


Show node’s local configuration

Display all local configurations of the node with ID CASGt8088

$ ais show config local CASGt8088
PROPERTY                         VALUE
confdir                          /home/divaturi/.ais8
log_dir                          /tmp/ais/8/log
host_net.port                    8088
host_net.port_intra_control      9088
host_net.port_intra_data         10088
fspaths.paths                    /tmp/ais/mp1/8,/tmp/ais/mp2/8,/tmp/ais/mp3/8,/tmp/ais/mp4/8,/tmp/ais/mp5/8
test_fspaths.root                /tmp/ais
test_fspaths.count               5
test_fspaths.instance            8

Show cluster configurations on a node

Display all cluster configurations (and overrides) of the node with ID CASGt8088

$ ais show config inherited CASGt8088
PROPERTY                                 VALUE                                                           DEFAULT
auth.enabled                             false                                                           -
auth.secret                              aBitLongSecretKey                                               -
backend.conf                             map[]                                                           -
checksum.enable_read_range               false                                                           -
checksum.type                            xxhash                                                          -
checksum.validate_cold_get               true                                                            -
checksum.validate_obj_move               false                                                           -
checksum.validate_warm_get               false                                                           -
client.client_long_timeout               30m                                                             -
# only 10 lines of output shown

Show cluster LRU config section

Display only the LRU config section of the global config

$ ais show config cluster lru
lru.dont_evict_time	    1s
lru.capacity_upd_time	10m
lru.enabled		        true

$ ais show config cluster space
space.cleanupwm		    70
space.lowwm		        80
space.highwm		    90
space.out_of_space	    95

Update cluster configuration

ais config cluster NAME=VALUE [NAME=VALUE...]


$ ais config cluster <TAB-TAB>
Display all 108 possibilities? (y or n)

$ ais config cluster time<TAB-TAB>
$ ais config cluster timeout.<TAB-TAB>
timeout.cplane_operation    timeout.max_host_busy       timeout.send_file_time
timeout.join_startup_time   timeout.max_keepalive       timeout.startup_time

And so on.

Updating is done by specifying name-value pairs. Use completions to help you remind (and/or type) the name and specify the new value. Use space or the = sign to delineate names from values.

NOTE: to see the current (pre-update) value, simply press Enter.

For example:

$ ais config cluster lru.enabled
lru.enabled      true

$ ais config cluster lru.enabled=false
	    "lru.enabled": "false"

cluster config updated

Set multiple config values in one shot

Change periodic.stats_time and disk.disk_util_low_wm config values for the entire cluster.

$ ais config cluster periodic.stats_time=10s disk.disk_util_low_wm=40
Config has been updated successfully.

Update node configuration

ais config node NODE_ID inherited NAME=VALUE [NAME=VALUE...]


ais config node NODE_ID local NAME=VALUE [NAME=VALUE...]

Usually, the steps:

  1. Select a node or use <TAB-TAB> to complete the selection.
  2. Next, select inherited to update cluster-level values. Alternatively, type or select local.
  3. Update selected value. Name and value can be separated either with = character or with a space.

When updating inherited values, keep in mind: all previous overrides can be undone using ais config reset command.

Set multiple config values

# Change `periodic.stats_time` and `disk.disk_util_low_wm` config values for node CMhHp8082.

$ ais config node CMhHp8082 periodic.stats_time=10s disk.disk_util_low_wm=40
Config has been updated successfully.

Reset configuration

ais config reset [NODE_ID]

Reset configuration for a specific daemon or the entire cluster back to the cluster configuration. That is, all local overrides will be removed and the cluster configuration will be applied to all nodes. To reset the configuration for the entire cluster, do not specify a DEAMON_ID argument.

# Discard local overrides for all nodes:

$ ais config reset
config successfully reset for all nodes
# Reset node's configuration to the current cluster-level values:

$ ais config reset CMhHp8082
config for node "CMhHp8082" successfully reset

CLI own configuration

CLI (tool) has configuration of its own. CLI (tool) can be used to view and update its own config.

Show CLI configuration

ais config cli show [--path] [--json]

Display the current CLI configuration. If --path is set, display only the path to the CLI configuration file.


$ ais config cli show
PROPERTY                         VALUE
aliases				 cp => 'bucket cp'; create => 'bucket create'; evict => 'bucket evict';
                                 ls => 'bucket ls'; rmb => 'bucket rm'; start => 'job start';
				 blob-download => 'job start blob-download'; download => 'job start download';
				 dsort => 'job start dsort'; stop => 'job stop'; wait => 'job wait';
				 get => 'object get'; prefetch => 'object prefetch'; put => 'object put';
				 rmo => 'object rm'
cluster.skip_verify_crt		 false
default_provider		 ais
no_color			 false
no_more				 false
timeout.http_timeout		 0s
timeout.tcp_timeout		 60s
verbose				 false

$ ais config cli show --path

Change CLI configuration

ais config cli set NAME=VALUE [NAME=VALUE...]

Modify the CLI configuration. The configuration file is updated only if all new options are applied without errors. If an option name does not exist or value is incorrect the operation is aborted.


$ ais config cli set timeout.tcp_timeout 61s
"timeout.tcp_timeout" set to: "61s" (was: "60s")

$ ais config cli show --json
    "cluster": {
        "url": "",
        "default_ais_host": "",
        "default_docker_host": "",
        "client_crt": "",
        "client_crt_key": "",
        "client_ca_tls": "",
        "skip_verify_crt": false
    "timeout": {
        "tcp_timeout": "60s",
        "http_timeout": "0s"
    "auth": {
        "url": ""
    "aliases": {
        "wait": "job wait",
        "cp": "bucket cp",
        "ls": "bucket ls",
        "prefetch": "object prefetch",
        "rmo": "object rm",
        "dsort": "job start dsort",
        "get": "object get",
        "rmb": "bucket rm",
        "start": "job start",
        "put": "object put",
        "stop": "job stop",
        "blob-download": "job start blob-download",
        "create": "bucket create",
        "download": "job start download",
        "evict": "bucket evict"
    "default_provider": "ais",
    "no_color": false,
    "verbose": false,
    "no_more": false