[Samba] TOO MANY OPEN FILES when adding printer driver

[Peter Koch]

Dear Samba experts,

I'm trying to add a printer driver for a Canaon TM-255 plotter
to out samba4 machine.

While most printer drivers consist of a handful of files, this plotter
requires 149 driver files.

I'm adding the driver via:

FILES="CNWT10GM.UPD,,CNWUO411.DLL,.... 142 more files"
rpcclient -U Administrator%nav852 SERV00 -c "adddriver \"Windows x64\"
\"Canon TM-255:CNWUOM.DLL:CNWT10GM.XPD:CNWUOMUI.DLL:NULL:NULL:$FILES\""

And this fails with WERR_APP_INIT_FAILURE

If I reduce the list of extra files to 116 files everything works fine.
If the list of extra files has >=117 files the following messages
show up in /var/samba/log.rpcd_spoolss

[2024/12/08 19:25:42.072125,  0]
../../source3/printing/nt_printing.c:1482(move_driver_file_to_download_area)
  move_driver_file_to_download_area: Unable to rename
[x64/CPC1RUW1.DLL] to [x64/3/CPC1RUW1.DLL]:
NT_STATUS_TOO_MANY_OPENED_FILES
[2024/12/08 19:25:42.073567,  0]
../../source3/rpc_server/spoolss/srv_spoolss_nt.c:8716(_spoolss_AddPrinterDriverEx)
  _spoolss_AddPrinterDriverEx: move_driver_to_download_area failed -
WERR_APP_INIT_FAILURE

How do I increase the max number of open files for rpcd_spoolss

Kind regards

Peter