index.conf file query

[isha_ish]

what does the below DataSize MB means on the index.conf file. just wanted to know how it works

homePath = volume:hot1/fxmp_core_prod/db
coldPath = volume:cold1/fxmp_core_prod/colddb
thawedPath = $SPLUNK_DB/fxmp_core_prod/thaweddb
homePath.maxDataSizeMB = 2048 --> what does this implies
maxTotalDataSizeMB = 5120 --> what does this implies

[inventsekar]

homePath.maxDataSizeMB = <nonnegative integer>
* Specifies the maximum size of 'homePath' (which contains hot and warm
  buckets).
* If this size is exceeded, splunkd moves buckets with the oldest value
  of latest time (for a given bucket) into the cold DB until homePath is
  below the maximum size.
* If you set this setting to 0, or do not set it, splunkd does not constrain the
  size of 'homePath'.
* The highest legal value is 4294967295.
* Splunkd ignores this setting for remote storage enabled indexes.
* Default: 0

maxTotalDataSizeMB = <nonnegative integer>
* The maximum size of an index, in megabytes.
* If an index grows larger than the maximum size, splunkd freezes the oldest
  data in the index.
* This setting only applies to hot, warm, and cold buckets. It does
  not apply to thawed buckets.
* CAUTION: This setting takes precedence over other settings like
  'frozenTimePeriodInSecs' with regard to data retention. If the index
  grows beyond 'maxTotalDataSizeMB' megabytes before
  'frozenTimePeriodInSecs' seconds have passed, data could prematurely
  roll to frozen. As the default policy for rolling data to frozen is
  deletion, unintended data loss could occur.
* Splunkd ignores this setting on remote storage enabled indexes.
* Highest legal value is 4294967295
* Default: 500000

https://docs.splunk.com/Documentation/Splunk/8.0.6/Admin/Indexesconf

[richgalloway]

homePath.maxDataSizeMB specifies how much disk space the hot and warm buckets can use.  Once this limit is reached buckets are rolled to cold.

maxTotalDataSizeMB specifies how much disk space the hot, warm, and cold buckets can use.  Once this limit is reached buckets are frozen.

See $SPLUNK_HOME/etc/system/README/indexes.conf.spec