Link to home
Start Free TrialLog in
Avatar of sunhux
sunhux

asked on

Does winscp has checksum feature?

Previously when we transferred a 20GB gz  Solaris file down to PC's
local HDD & then from the local PC HDD, transfer to a USB HDD, our
DLP corrupted the gz file when it's transferred from local HDD to USB

We have since resolve that but to prevent untoward corruption in
future for copying of critical files to USB HDD,

Q1:
Does Winscp has checksum feature that checks at Unix end & at
PC end?

Q2:
If so I would rather use Winscp to transfer directly to USB HDD.
Avatar of sunhux
sunhux

ASKER

> If so I would rather use Winscp to transfer directly to USB HDD.
ie transfer from Unix server directly to USB HDD
SOLUTION
Avatar of ste5an
ste5an
Flag of Germany image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of sunhux

ASKER

> It's not about the specific client, it's about the used protocol
Was told by my ex-colleagues in the bank that they had encountered
corruption when transferring using sftp or scp (betwn AS400 & Unix)
thus ConnectDirect was the preferred tool to do transfer as it has
checksumming specifically.

ConnectDirect will not save the file if the link is interrupted but would
sftp/scp save the file if transfer is interrupted?


One last question:
in Winscp, the "Transfer Settings" is usually set as "Default" : under
what circumstances will it use Binary or ASCII ?  My Unix ex-colleagues
had seen cases when it used Binary & sometimes Ascii for "Default"
AS 400 stores file differently... from UNIX. WinSCP always uses binary.
so the corruption is a difference of opnion of fileformats.

unless FTP is used then ascii may be chosen... FTP publishes passwords though.

Checksumming tools will not help either as both ends of the connection have a different opnionion on what constirutes a valid file format.
Avatar of sunhux

ASKER

The sftp file corruption with AS400 is not a matter of file format but  missing
lines/records.  We'll leave this aside.

Will take it that winscp has checksumming feature: it can even resume a
transfer from where it was last disrupted.



To close this thread, need an answer for one last question:

in Winscp, the "Transfer Settings" is usually set as "Default" : under
what circumstances will it use Binary or ASCII ?  My Unix ex-colleagues
had seen cases when it used Binary & sometimes Ascii for "Default"
With: Binary bytes are transfered as is... blocks of bytes.
Ascii transfers will convert files in records ending in CR/LF during transfer.  (chr(13), chr(10))

On unix -> unix the difference is moot, to other systems it may be relevant.
On unix a text file is  any file which which uses LF character  (chr(10))  and and of line character.

FTP transfers (port 21) does know this difference. SCP transfers (port 22) don't have this difference.
Resume is not based on checksum, it asks the remote how long the file is and then starts sending
from that point on.
Avatar of sunhux

ASKER

There are occasions the "Transfer Setting" of Default will use Ascii
& sometimes Binary   as encountered by my ex-colleagues.

So does Winscp detect by the extension of the file eg: .txt will auto
default to Ascii  while  .bin  or  .zip   or .gz will default to  Binary?
ASKER CERTIFIED SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial