Hello Steve, From the mount.cifs man pages,the wsize can be 16M. I use samba server to test on upstream. But the wsize is always 8M if specify the wsize > 8M. How can I make wsize=16M? My test: # uname -r 5.0.0-rc1+ # mount //localhost/test cifs -o user=root,password=redhat,wsize=16777216,vers=3.11 # mount |grep cifs //localhost/test on /root/cifs type cifs (rw,relatime,vers=3.1.1,cache=strict,username=root,domain=,uid=0,noforceuid,gid=0,noforcegid,addr=0000:0000:0000:0000:0000:0000:0000:0001,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=1048576,wsize=8388608,echo_interval=60,actimeo=1,user=root) -- Best regards! XiaoLi Feng 冯小丽 Red Hat Software (Beijing) Co.,Ltd filesystem-qe Team IRC:xifeng,#channel: fs-qe Tel:+86-10-8388112 9/F, Raycom