Paul Millar

Does the door's log file (the log file of the domain hosting the door) contain any entries regarding these failing transfers?

Two more questions: Do you see any SRM upload activity (in particular that failed) on this dCache instance? Do you see any xrootd uploads with the "Persist On Successful Close"...

Do any of the `srmAbortFiles` requests match the files with the problematic FTP transfers ... or do they happen at about the same time as the transfers?

Detecting xroot POSC isn't completely trivial. You're looking for a xroot `kXR_open` request in the access log file with the `options` flag `0x1000` set. Here's a sed one-liner that pulls...

Could look at the pool hosting one of these zero-length precious files. Does the pool's log file contain anything significant?

Could you pull out the billing log entries for the failed upload for the file with PNFS-ID `000026B4D53F3AB44849A64D4308A52BD53C` ? Also, could you confirm which pool(s) have a zero-length replica of...

In [a previous comment](https://github.com/dCache/dcache/issues/6176#issuecomment-951974532), you ran `rep ls` on all pools with problematic PNFS-IDs. This particular file appears to be stored on two pools. This gives me a hint on...

As a suggestion: perhaps we should focus on one specific transfer that resulted in a precious zero-length file and try to understand what went wrong. Currently, it seems like this...

OK, I now understand what has happened. In 2009, dCache was updated so it no longer logs `uid` and `gid` values in the database (commit `aee2fa25`). Looking at the patch,...

So, the question is: do we fix this by starting to log uid and gid values (potentially breaking existing sites) or ask older sites to update their schema (i.e., `ALTER...