smbfs 2 GB file size limit

[David Horn]

On Tue, Nov 18, 2008 at 7:06 AM, Derek Ragona
<derek at computinginnovations.com> wrote:
> At 12:23 AM 11/18/2008, David Horn wrote:
>
> On Mon, Nov 17, 2008 at 8:36 PM, Derek Ragona
> <derek at computinginnovations.com> wrote:
>> I have FreeBSD 7.0 Release and if I mount_smbfs  a network NTFS share I
>> have
>> a 2 GB size limit on files.  I checked the handbook and list archives but
>> have not found a solution.
>
> I just ran a quick test, and was not able to reproduce this issue with
> the mount_smbfs from FreeBSD 7.0.  I tried against a Windows 2003
> Server SP2, Windows XP SP3, and Samba 3.0 {on FreeBSD 7} with a 3.5GB
> file.
>
> Was your issue with reading from or writing to a SMB share ?
>
> It was writing to a smb share.
>
>
> What is the server software and OS version ?
> (if Microsoft Windows, please include Service Pack number as well, as
> it might make a difference)
>
> Windows 2003 server 32bit.
>
> How much disk space is left on your server volume ?
>
> Over a terabyte free
>
> Are there disk quotas enabled on the server ?
>
> None
>
> What error message are you getting from your FreeBSD client (if any) ?
>
> No error message, it just stopped writing at 1 Gb.  I was doing this using
> scp.

Whoa, hopefully you just made a few typos here, or we are going down
the wrong path of investigation.

Did you really mean to say scp or cp ?
     scp(1)                   - secure copy (remote file copy program)
     cp(1)                    - copy files

If you really meant scp, then the problem is not mount_smbfs, but
instead likely a buggy scp client or server (which does not use smb
for transport, but ssh)

What is the exact byte count that your write stops at ?  You
originally stated 2GB, then 1GB.

>
> Can you check the smb server logs and see if you are getting any error
> messages there ?
>
> Well I'm just mounting the volume to FreeBSD from the Windows server so not
> sure I'll find much in the logs besides the system log, but I will look.
>
> You may want to get a Wireshark trace and see if you can capture the
> SMB error message/error code.
>
> I have heard of people running into similar problems when running
> against older server software (NT 4.0/old samba) when the SMB session
> did not negotiate large file/large write support (a function of the
> SMB server capabilities session negotiation)
>
> I saw posts to that effect and that you needed samba 3.x to support large
> files sizes, and the lfs option.  But the mount_smbfs doesn't offer any
> large file option.
>

Only bother with this next bit if you are morbidly curious as to how
things work rather than just want to solve your problem, as it gets
into the nitty gritty details of smb:

mount_smbfs will allow for lfs (CAP_LARGE_FILE) automatically by
specifying it's dialect capabilities in the smb negotiation.

If you umount your smb share, then start a tcpdump you can capture the
smb negotiation "Capabilities" bitmask to see if CAP_LARGE_FILE is
being negotiated - the server specifies this capability.  The client
just sends the dialects of smb supported.    For example:

tcpdump -vvv -s 1500 -i em0 host server.example.com | grep Capabilities

{  where em0 is the network interface in use on FreeBSD and
server.example.com is the hostname/ip address of your smb server  }

Then do a mount of the smb share (while tcpdump is running) and you
should capture the Capabilities negotiated.

For example:

Capabilities=0x1F3FD

If you decode the bitmask by using this reference :
http://msdn.microsoft.com/en-us/library/aa302230.aspx {hint:  only
look at the last four bytes of the Capabilities line (e.g. F3FD in my
example)} Or if you have kernel source installed, you can look in
/usr/src/sys/netsmb/smb.h for the details.

   - Capabilities: 0x0001F3FD
      RawMode:            (...............................1) Supports
SMB_COM_READ_RAW and SMB_COM_WRITE_RAW (CAP_RAW_MODE)
      MpxMode:            (..............................0.) No
Support for SMB_COM_READ_MPX or SMB_COM_WRITE_MPX (CAP_MPX_MODE)
      Unicode:            (.............................1..) Supports
Unicode Strings (CAP_UNICODE)
      LargeFiles:         (............................1...) Supports
large files with 64-bit offsets (CAP_LARGE_FILES)
      NTSMBs:             (...........................1....) Supports
SMB NTLM 0.12 dialect commands (implies CAP_NT_FIND) (CAP_NT_SMBS)
      RPCRemoteAPIs:      (..........................1.....) Supports
remote API requests using RPC over named pipe connections
(CAP_RPC_REMOTE_APIS)
      NTStatus:           (.........................1......) Can
respond with 32-bit NT status codes in Status (CAP_NT_STATUS)
      LevelIIOplocks:     (........................1.......) Supports
Level II oplocks ( CAP_LEVEL_II_OPLOCKS)
      LockAndRead:        (.......................1........) Supports
SMB_COM_LOCK_AND_READ and SMB_COM_WRITE_AND_UNLOCK (CAP_LOCK_AND_READ)
      NtFind:             (......................1.........) Supports
Windows NT information level requests (SMB_QUERY_?, SMB_SET_?)
(CAP_NT_FIND)
      Reserved_bits10_11: (....................00..........) Reserved
      Dfs:                (...................1............) This
server is Distributed File System (Dfs) aware (via
TRANS2_GET_DFS_REFERRAL) (CAP_DFS)
      InfolevelPassthru:  (..................1.............) Supports
Windows NT information level pass-through requests
[SMB_INFO_PASSTHROUGH] (CAP_INFOLEVEL_PASSTHRU)
      LargeReadx:         (.................1..............) Supports
large read operations (CAP_LARGE_READX)
      LargeWritex:        (................1...............) Supports
large write operations (CAP_LARGE_WRITEX)
      Lwio:               (...............1................) Reserved

>
>>  Supposedly there is an smbmount as part of the
>> standard samba, but that doesn't seem to install from any of the samba
>> ports.
>
> smbmount is not included in the FreeBSD port of samba, as it is Linux
> kernel specific.  mount_smbfs(8) is the correct userland app.
>
> You could always try the samba smbclient(1) to access SMB shares using
> an FTP-like environment.
>
> I saw that as an option.  I may try that to test this issue.
>
>
>>
>> Any help would be appreciated.
>
> Sorry I do not have a good solution for you.  Perhaps someone else
> will give you better advice.
>
> Thanks for the help!
>
>         -Derek
>
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