On Sep 2, 2010, at 7:51 AM, Tayade, Nilesh wrote: >> -----Original Message----- >> From: Chuck Lever [mailto:chuck.lever@xxxxxxxxxx] >> Sent: Wednesday, September 01, 2010 9:16 PM >> To: Chuck Lever >> Cc: Tayade, Nilesh; linux-nfs@xxxxxxxxxxxxxxx >> Subject: Re: NFS version4 maximum on-the-wire data size. >> >> >> On Sep 1, 2010, at 11:41 AM, Chuck Lever wrote: >> >>> >>> On Sep 1, 2010, at 5:39 AM, Tayade, Nilesh wrote: >>> >>>> Hi, >>>> >>>> I am unable to get the exact count for the amount of on-the-wire > data >>>> size that NFSv4 supports. >>>> >>>> I could get exact figures in case of NFSv3 >> (http://nfs.sourceforge.net). >>>> It's 60KB when NFSv3 is used over UDP and implementation dependent > in >>>> case it is used over TCP. Any idea about NFSv4 statistics? >>>> >>>> Any pointers would be appreciated. >>> >>> NFSv4 reads and writes can be as large as the maximum payload size > of >> the underlying transport. NFSv4 does not support UDP, but on TCP, the >> maximum payload size is usually approximately (2 ** 31 - 1) - (RPC > header >> + NFS overhead). >> >> But you were probably not asking about the theoretical limits of the >> underlying transport. >> >> The Linux NFS client limits read and write payload size to a megabyte. >> Servers may limit it further. > > Thanks for the information. It helps. > > Also we use 2.6.22 kernel version (it's old, and have no option of > changing it) on our Intel boxes. I was just wondering is there any > kernel-version Vs. NFS version mapping (I assume it's not, but just to > be sure about)? I have never seen NFSv2 running on our boxes. I am going > to write certain applications on top of NFS. So wanted to be sure if > NFSv2 should be supported at all (is it so widely used on recent > systems, compared to NFSv3/v4)? With certain exceptions, applications shouldn't generally be aware of what NFS version is in use. Without knowing more about your applications, it's hard to make any more than a very general statement. -- chuck[dot]lever[at]oracle[dot]com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
