After switching to Archive mode (from Circular mode to keeping archive logs on the disk) we had C0000000 folder where archive logs were copied. Now I noticed that folders C0000001, C0000002, C0000003 and C0000004 are created where C0000001 and C0000002 and C0000003 have only one LOG file. Archive logs keep coming to C0000004 sub folder.
Time when those folders are created are some random times (for example it is not the time when online backup was performed).
Why those C000000x folders are created and is this regular behavior or we should be concerned?