On 09/28/2010 07:07 AM, Simon Andrews wrote: > I have a fedora 13 box on which I have a remote mounted nfs share over a > fairly slow (10Mb/s) link. I'm then transferring data onto this share > from a different machine using scp. > > The problem is that after scp reports that it's 100% complete the > program will hang for ~20 mins before it will move on to another file. > At this point it can't be killed. > > It looks like the nfs daemon is caching write data (around 2GB of it) > which lets scp think its finished when actually there's loads of data > sitting in a write buffer. The hanging is presumably the time it takes > to flush the buffer (there is a process called nfsiod which is active > during this time and df shows data is still being written). > > Does anyone know how to either make this buffer smaller, or get rid of > it all together so the scp can accruately report on its progress? > > Thanks > > Simon. > I understand you mean your desktop nfs-mounts a directory exported to your machine by a server over a 10 mb/s link. I understaand you mean that you have write permissions to write to this nfs mounted directory on your machine. I understand that you scp from a third machine (again at 10 mb/s ???? - you did not specify this part) to the nfs mounted directory on YOUR machine. Just to get the data from the third machine to yours before it is even sent to the nfs server): On a 10megabit/s link, only 80% of which is payload data, transferring 2GB (I assume you mean binary GB): .80 * 10000000 = 8000000 bits/s payload data 8000000 / 8 = 100000 bytes/s payload data 2147483648 / 1000000 = 2147.48 number of seconds it takes to download 2 GB. 2147.48 /60.00 = 35.79 minutes to download 2GB. So, that's close enough to your 20 minutes download time. I am being a bit pessimistic here as to how much of the ether bandwirdth is used for payload data. At 90%, the transfer time comes down to 31 minutes. So, 20 minutes is absolutely miraculous!!! Be HAPPY!! -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
