198600b71SDaniel W. S. Almeida 298600b71SDaniel W. S. Almeida================================== 398600b71SDaniel W. S. AlmeidapNFS SCSI layout server user guide 498600b71SDaniel W. S. Almeida================================== 598600b71SDaniel W. S. Almeida 698600b71SDaniel W. S. AlmeidaThis document describes support for pNFS SCSI layouts in the Linux NFS server. 798600b71SDaniel W. S. AlmeidaWith pNFS SCSI layouts, the NFS server acts as Metadata Server (MDS) for pNFS, 898600b71SDaniel W. S. Almeidawhich in addition to handling all the metadata access to the NFS export, 998600b71SDaniel W. S. Almeidaalso hands out layouts to the clients so that they can directly access the 1098600b71SDaniel W. S. Almeidaunderlying SCSI LUNs that are shared with the client. 1198600b71SDaniel W. S. Almeida 12*e70cc712SRandy DunlapTo use pNFS SCSI layouts with the Linux NFS server, the exported file 1398600b71SDaniel W. S. Almeidasystem needs to support the pNFS SCSI layouts (currently just XFS), and the 1498600b71SDaniel W. S. Almeidafile system must sit on a SCSI LUN that is accessible to the clients in 1598600b71SDaniel W. S. Almeidaaddition to the MDS. As of now the file system needs to sit directly on the 1698600b71SDaniel W. S. Almeidaexported LUN, striping or concatenation of LUNs on the MDS and clients 1798600b71SDaniel W. S. Almeidais not supported yet. 1898600b71SDaniel W. S. Almeida 1998600b71SDaniel W. S. AlmeidaOn a server built with CONFIG_NFSD_SCSI, the pNFS SCSI volume support is 2098600b71SDaniel W. S. Almeidaautomatically enabled if the file system is exported using the "pnfs" 2198600b71SDaniel W. S. Almeidaoption and the underlying SCSI device support persistent reservations. 2298600b71SDaniel W. S. AlmeidaOn the client make sure the kernel has the CONFIG_PNFS_BLOCK option 2398600b71SDaniel W. S. Almeidaenabled, and the file system is mounted using the NFSv4.1 protocol 2498600b71SDaniel W. S. Almeidaversion (mount -o vers=4.1). 25