Prune - FOSSIL_RESURRECT - Chunk already exists

Support
#1

Hi,

would like to ask for your support about the following:

My schedule is this “Backup/Check/Prune/Check”. For the first time i received the following in the Prune log:

Running prune command from /cache/localhost/all
Options: [-log prune -storage hidden -a -threads 10 -keep 0:7]
2021-11-17 01:01:33.066 INFO STORAGE_SET Storage set to hidden
2021-11-17 01:01:34.128 INFO BACKBLAZE_URL download URL is: https://f003.backblazeb2.com
2021-11-17 01:01:35.498 INFO RETENTION_POLICY Keep no snapshots older than 7 days
2021-11-17 01:01:39.168 INFO FOSSIL_COLLECT Fossil collection 18 found
2021-11-17 01:01:39.168 INFO FOSSIL_DELETABLE Fossils from collection 18 is eligible for deletion
2021-11-17 01:01:39.168 INFO PRUNE_NEWSNAPSHOT Snapshot AppData revision 225 was created after collection 18
2021-11-17 01:01:39.193 INFO PRUNE_NEWSNAPSHOT Snapshot DockerCompose revision 230 was created after collection 18
2021-11-17 01:01:39.195 INFO SNAPSHOT_DELETE Deleting snapshot AppData at revision 218
2021-11-17 01:01:39.213 INFO SNAPSHOT_DELETE Deleting snapshot DockerCompose at revision 223
2021-11-17 01:01:39.696 INFO CHUNK_DELETE The chunk fa2841323a4c5206845b2a65d35c371151c55f8720e2a45edcf587dc8bb18d32 has been permanently removed
2021-11-17 01:01:40.061 INFO CHUNK_DELETE The chunk c02d7089260ad42a6dee1c235ed4e2070e0fa6c6e6249ba3291a673c00020963 has been permanently removed
2021-11-17 01:01:40.096 INFO CHUNK_DELETE The chunk 8be66d61618dea3350207b94476234d8f884ddbac920abd6638415bc087d09ff has been permanently removed
2021-11-17 01:01:40.119 INFO CHUNK_DELETE The chunk 7c6b2664c16120cc047bb8710c258da0bd0a0872fe2acf0b79e45bca00532192 has been permanently removed
2021-11-17 01:01:40.123 INFO CHUNK_DELETE The chunk 2cf3f693532d2859153506f79c34ef3adfe46e14c9d73e2a449b06f53707790f has been permanently removed
2021-11-17 01:01:40.176 INFO CHUNK_DELETE The chunk a5ab38cce5941287f293ad307254773a9d0012dad4469c9a07a8421c8175b059 has been permanently removed
2021-11-17 01:01:40.265 INFO CHUNK_DELETE The chunk 945a9a6d07cec80311e532edb2ad2679a7fd1708f7de1f384a4a66dcbd0c8ff1 has been permanently removed
2021-11-17 01:01:40.355 INFO CHUNK_DELETE The chunk 281270e04371ac7b1fb27f6b07ac952ec82b814154b5f7cf06c01e5bdb07e7cd has been permanently removed
2021-11-17 01:01:40.472 INFO CHUNK_DELETE The chunk 0ceba740f984157979a0ac8778765e9c5b4eda5565029db7f580b27fa64e9c87 has been permanently removed
2021-11-17 01:01:40.515 INFO CHUNK_DELETE The chunk c20a162c9f647c92791da4381dc1b5d92dac1eb8dc832c36e698d7a08f78b1e4 has been permanently removed
2021-11-17 01:01:40.716 INFO CHUNK_DELETE The chunk 5a967aae4b444350c0018dc7549e0b200d93357a2a3c2c491320a1e2f3c7a21e has been permanently removed
2021-11-17 01:01:40.745 INFO FOSSIL_RESURRECT The chunk 65d2e7f18a74ca70b787c00b7d5c1d66a35f60156dded0e59861424b48a01ca4 already exists
2021-11-17 01:01:40.749 INFO CHUNK_DELETE The chunk abd8765c9f6d0684e66f2a13e73e179e1dbcf830965d9803954a3b8a93fc6853 has been permanently removed
2021-11-17 01:01:40.872 INFO CHUNK_DELETE The chunk 4c66cf2a08b5ffa5bc99b7f174a5b48c2f9fdaff308b23bf0eef585edf5ffaa7 has been permanently removed
2021-11-17 01:01:41.051 INFO CHUNK_DELETE The chunk 342b66601b8b3603bb58ab973c84c2ce685cb67908e465268227bc9b440c288f has been permanently removed
2021-11-17 01:01:41.130 INFO CHUNK_DELETE The chunk b64d1874453e0c28f34d1d1abc17ba64bf2a22771871ba36d9ea84a90c83c955 has been permanently removed
2021-11-17 01:01:41.830 INFO CHUNK_DELETE The chunk 51bfa713580babad00ba0c58f2722a9444dcfb5c5867ad7084a9c83ac9351a11 has been permanently removed
2021-11-17 01:01:54.611 INFO FOSSIL_COLLECT Fossil collection 19 saved
2021-11-17 01:01:55.174 INFO SNAPSHOT_DELETE The snapshot DockerCompose at revision 223 has been removed
2021-11-17 01:01:55.552 INFO SNAPSHOT_DELETE The snapshot AppData at revision 218 has been removed

What means that a fossil already exists during the prune activity?

Thanks in advance!

#2

That means when a fossil is turned back into a chunk (by renaming) the chunk with the same name already exists. This can happen if a new backup uploads the same chunk again so it is completely normal.

1 Like
#3

Thanks for your reply but I still can’t understand this process. Why the resurrect of a chunk during the prune and not during the backup?

Also why it was trying to resurrect a chunk in the first place, and then find that a chunk with the same name already exist?

#4

It would be too much overhead for the backup to check if the fossil exists before uploading every new chunk.

This can happen when, say, a backup to be deleted contains an old version of a file, but later you revert that file to the old version and run the backup while the prune command is running. Your case may vary but this FOSSIL_RESURRECT message is the proof that the Two-Step Fossil Collection works and that you can simply delete every chunk not referenced by existing backups since some of them may be needed by a backup still in progress (which is unknown to the prune command).