This will happen if you end up with duplicate bucket ids in your index while splunk is running.
Some really weird problem with network filesystem might be responsible (do not use network filesystems for index and search unless you can guarantee their reliability). Bugs in a custom warmToCold script could be responsible. Pointing two splunk executables at one directory could be responsible.
It's pretty hard to make this happen.
But if it does happen, splunk may rename the warm bucket to this duplicate name.
Recommended steps:
This will happen if you end up with duplicate bucket ids in your index while splunk is running.
Some really weird problem with network filesystem might be responsible (do not use network filesystems for index and search unless you can guarantee their reliability). Bugs in a custom warmToCold script could be responsible. Pointing two splunk executables at one directory could be responsible.
It's pretty hard to make this happen.
But if it does happen, splunk may rename the warm bucket to this duplicate name.
Recommended steps: