[SOLVED] Unable to copy large files over NFS shared via SMB, receive I/O device error

ha1f3mpty · Post by **ha1f3mpty** » 2012/07/12 19:46:16

Hello all,

I will start off acknowledging that my current deployment may not be the most ideal, so if after reading my description you have other suggestions I would like to hear them. Here it goes.

I have a primarily Windows environment with a Linux system running CentOS 5.6 that is used to run some in-house developed tools. I am running a Windows 2008 R2 file server with Services for Network File System installed that is hosting all our data. I have made some folders on the Windows file server and shared them out via the NFS tab. I am able to mount the NFS shares to a local mount point on my Linux box, e.g. /nfsshare and can read / write without any issue.

Here is the trick part.

Because of the way Linux permissions work, or my understanding of how they work and Windows not working with them well, I am not able to do anything with the NFS shared folders though any Windows system other then mess with the NFS share permisisons. So that my users are able to browse and move files rround from the Windows clients I have reshared the NFS mount point, /nfsshare, through Linux SMB. I can UNC to the Linux system and see the SMB share and browse the contents but if I try to copy a file over to it I receive the error " The request could not be performed because of an I/O device error" on any file that is larger then about 20KB. If I transfer files that are 0-10KB or an empty folder it goes without an issue.

I dont know if this will simplify my explination or make it more confusing:

My Linux box auto mounts to
My Linux box then shares /nfsshare out through SMB
My Windows clients can look around the Linux SMB shares but are not able to copy files / folders

I have tested to see if it is the Linux or Windows Server box and it looks to be something in the Windows configuration because if I share a folder though SMB that is not from the Windows NFS I am able to copy files from the Windows clients without any issue.

This did work for a while then one day the I/O error showed up and I cannot remember making any changes. I have searched high and low and cannot find anything. I don't know if my search skills are failing me or if my implementation is just so screwed up that no one else has attempted it.

ha1f3mpty · Post by **ha1f3mpty** » 2012/07/13 22:34:56

Ok, well I figured out what the issue was. After working for about a week, probably more, on configuring changing resetting and reconfiguring our Linux and Windows servers it dawned on me that maybe it was the Windows clients that we were connecting and performing the file transfers from. After a quick format and fresh Windows 7 install, I want to move to Windows 7 anyway, and bang I can transfer files from my Windows client through the Linux SMB share of the Windows NSF file server. I am not 100% sure if it is an incompatibility with Windows XP or one of the security settings that is set on them. I did remove all Group Policy and restored the security settings with the default security template on one of the XP systems and I still could not transfer files. I will try a fresh XP install later and see if it will work, if it does then its a security setting but I don't think I will track it down because Windows 7, all locked down, looks to be working fine.

AlanBartlett · Post by **AlanBartlett** » 2012/07/13 23:51:18

Thank you for reporting back with your self-found solution.

On your behalf and for posterity, the initial post of this thread is also marked [SOLVED].