Decnet LINUX / dncopy : binary filesize becomes multiples of 512 bytes

Expected :
-----------
dncopy -mblock -b512 FromLINUX_file1 ToVMS_file1
dncopy -mblock -b512 FromVMS_file1 ToLinux_file2

should give EXACTLY the same files (FromLINUX_file1 and ToLinux_file2) .....

What happen :
-------------
ToLinux_file2 is greater than FromLINUX_file1.
ToVMS_file1 and ToLinux_file2 become multiples of 512 bytes !

---------------------------------------

We need to copy binary files exactly to its size, in both direction (Linux->VMS) or (VMS->Linux).
From VMS to Linux is OK, but,
From Linux to VMS is wrong !
From Linux to VMS is wrong, we found that the transferred files are a little bigger (they become multiples of 512 bytes).

The problem is the same with the “Linux fal service” as with the “dncopy” command.

dndir command example :
- dndir -mblock -b512 ‘nodename”user password”::[]file2.bin .
- dndir -mblock -b512 linuxbinaryfile.bin ‘nodename”user password”::[]file1.bin

fal parameters
/etc/dnetd.conf :
FAL 17 Y none fal -ae –f /etc/dnetd.conf.fal
/etc/dnetd.conf.fal
.bin b 512
.exe b 512
.txt r
etc…
-----------------------------------
Example with a test file that contains 43251 characters = “84 sectors + 243 bytes” : zi_43215.bin
(On VMS hardware) dump /header zi_43215.bin
…
Structure level and version 2, 1
…
Record type : Fixed
File organization : Sequential
Record attributes : <none spefified>
Record size : 512
Highest block : 90
End of file block : 85
End of file byte : 243
Bucket size : 0
Fixed control area size : 0
Etc…

dncopy -mblock -b512 ‘nodename”user password”::ZI_43251.BIN .
ls –l
-rw-r—r-- 1 user user zi_43251 2017-11-13 17:54 zi_43251.bin
(It is OK)

// I delete the file on VMS, than I do :
dncopy -mblock -b512 zi_43251.bin ‘nodename”user password”::ZI_43251.BIN

(On VMS hardware) dump/header zi_43215.bin
…
Structure level and version 2, 1
…
Record type : Fixed
File organization : Sequential
Record attributes : <none spefified>
Record size : 512
Highest block : 90
End of file block : 86
End of file byte : 0
Bucket size : 0
Fixed control area size : 0
Etc…
(It is WRONG)
--------------------------------------------------------------

We tried to understand and correct the problem, but without success !

Is it a bug or a limitation ?
Perhaps we make mistakes in parameters usage ?

Do you know if there is a workaround or fix ?

Why are you using block mode and not record mode?

Hello and welcome to LQ.


http://www.decuslib.com/decus/vmslt0...aq-single.html Streamlf issue??

Thank's "smallpond" and "jefro"

//---

It's a good idea to re-read the web page http://www.decuslib.com/decus/vmslt0...aq-single.html
But I didn't find any other good idea !

I use VMS systems and dnprogs for a long time (15 years !).
I'm pretty familiar with file format issues.
I think that the best way (for us) is really the binary mode "block".
But today, we have a new need : the exact binary filesize with the "dnprogs package" !.

//---

Why are you using block mode and not record mode?
-----
The "block mode" works fine from VMS to Linux.
From Linux to VMS, it also works good, except the wrong "End Of File" (the file is a little bigger : the filesize becomes multiples of 512 bytes).
-----

We use block mode because we move binary files, which can be used on both side (VMS and Linux).
With StreamLF we have additionnal extra data in the VMS File (Linux->VMS).

//---

We will continue to seek a solution.
Thanks.