Hi, zfs_mknode is the function use by mknod syscall to create device special file in solaris kernel. I traverse the code and just found how they stores the minor number which is in znode's(disk inode of Linux) attributes struct called sa_bulk_attr field uint16_t sa_buftype which is of 16bit only. so, it just store minor number in this field. And I am failed to understand where/how the solaris exact stores major number from code traversing. so, can somebody clarify where/how the major number stores in solaris code or in znode(disk inode). the source is available online and following link is of zfs_znode.c file having zfs_mknode function... http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/fs/... Regards, Deepen Mehta