pgbasebackup is failing after truncate

HI

 

At present, I have some requirement to truncate the data base  to reclaim disk space and at the same time I need to take basebackup.

 

Seems, truncate is successfully reclaimed the space but pgbasebackup failed and reported the below error.

 

“could not stat file or directory ./base/16384/25600: Permission denied.

 

Further observation shows that truncate command reclaiming the space by making empty (not deleted)  these files in ./base/16384 folders.

 

Seems these filename are relfilenode in pg_class table to map filename to table name. Since truncate making empty these files and create new files to map the old table name, pgbasebackup is unable to synch with truncate and pointing to old files.

 

Also, the old files are not deleted from “base” folder.

 

Please let me know how to resolve this issue