On Wed, Sep 07, 2005 at 03:43:21PM -0500, Christopher R. Hertel wrote: > On Wed, Sep 07, 2005 at 10:15:37PM +0200, Axel Thimm wrote: > > After having setup our workarounds for NFS we are very happy with how > > it's working. Now we're looking at Samba. > > > > But we have quite a showstopper right at the beginning. The smb/cifs > > clients, be it smbclient or Windows XP, don't like their TCP stream > > being resetted and don't retry/reconnect (contrary to NFS). > > > > It looks like the protocol has no considerations for retries above the > > TCP/IP level. So when the TCP stream is torn on the server's side due > > to relocation (either due to crash/fencing or soft) any client > > smb/cifs activity is broken at that time. > > > > This means that any data transfer via smb/cifs shares during the > > relocation will fail, and there is nothing we can do on the server's > > side. Or is there? > > Windows clients will reconnect to the same server, and so will smbfs and > cifs-vfs. > > I just tested this. On a W/XP box I browsed through some directories on a > share served by Samba. I then shut Samba down, and tried viewing some > different subdirectories of the same share. Windows coughed up an error > dialog. I then restarted Samba and Windows got happy again. I could > browse through all of the subdirectories in the share. Yes, that does work, but what I wanted to setup is a transparent failover, so that network I/O recovers w/o any manual interaction. I.e. I don't want to (soft) relocate the samba shares onto another node due to load ballancing considerations and generate user visible I/O errors and failures on a dozen clients. > We've talked about Samba on GFS within the Samba Team, and various members > have done some digging into the problem (Volker most recently, if I'm not > mistaken). Samba must maintain a certain amount of state information > internally--including name mangling, locking, and sharing information > that--is peculiar to Windows+DOS+OS2 semantics. The problem is ensuring > that Samba's state information is also shared across the GFS nodes. > > I've not had time to keep up with this development thread, but I know that > the folks working on Samba-4 are aware of the issues involved. > > Chris -)----- > -- Axel.Thimm at ATrpms.net
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