Seafile GC

Seafile uses storage de-duplication technology to reduce storage usage. The underlying data blocks will not be removed immediately after you delete a file or a library. As a result, the number of unused data blocks will increase on Seafile server.

To release the storage space occupied by unused blocks, you have to run a "garbage collection" program to clean up unused blocks on your server.

The GC program cleans up two types of unused blocks:

1. Blocks that no library references to;
2. If you set history length limit on some libraries, the out-dated blocks in those libraries will also be removed.

Before running GC, you must shutdown the Seafile program on your server if you use the community edition. For professional edition, from version 3.1.11, online GC operation is supported. If you use Professional edition, you don't need to shutdown the Seafile program if you are using MySQL or PostgreSQL as database. This is because new blocks written into Seafile while GC is running may be mistakenly deleted by the GC program.

Run GC in version 3.1.2 and later

To run GC program

./seaf-gc.sh run

If you want to do sanity check before actually removing any data, you can use the --dry-run option

./seaf-gc.sh dry-run

It will show you the total block number vs. the number of blocks to be removed.

To check data integrity after running GC, you can use seaf-fsck

Run GC before version 3.1.2

To run GC program

cd seafile-server-{version}/seafile
export LD_LIBRARY_PATH=./lib:${LD_LIBRARY_PATH}
./bin/seafserv-gc -c ../../ccnet -d ../../seafile-data

If you built seafile server from source, just run

seafserv-gc -c ../../ccnet -d ../../seafile-data

After the GC program terminates, you may also check whether it mistakenly removed any useful data blocks:

seafserv-gc -c ../../ccnet -d ../../seafile-data --verify

It will print a warning if any useful blocks are missing.

If you want to do sanity check before actually removing any data, you can use the --dry-run option

seafserv-gc -c ../../ccnet -d ../../seafile-data --dry-run

It will show you the total block number vs. the number of blocks to be removed.

If the metadata of some libraries are damaged on the server, the GC program would stop proceeding because it can't tell whether a block is used by some damaged libraries or not. If you don't want to keep the data of the damaged library, you can run GC with --ignore-errors or -i option

seafserv-gc -c ../../ccnet -d ../../seafile-data --ignore-errors

This will mask the blocks of the damaged libraries as unused and delete them.