Hello. It has been a while since I've seen.. issues with nfs for the last time. Now I hit a limitation of number of groups in nfs3, and had to switch to nfs4. And immediately hit another problem, which makes the whole thing almost unusable for us. The problem is that each time the nfs server is rebooted, I have to - it boils down to - forcibly REBOOT each client which has some mounts from the said server. Because, well, remount - in theory - should be sufficient, but I can't perform remount because the filesystem(s) in question are busy. Here's a typical situation (after reboot): # ls /net/gnome/home ls: cannot access /net/gnome/home: Stale NFS file handle # mount | tail -n2 gnome:/ on /net/gnome type nfs4 (rw,nosuid,nodev,relatime,vers=4,rsize=262144,wsize=262144,namlen=255,soft,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.88.2,addr=192.168.88.4) gnome:/home on /net/gnome/home type nfs4 (rw,nosuid,nodev,relatime,vers=4,rsize=262144,wsize=262144,namlen=255,soft,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.88.2,addr=192.168.88.4) # umount /net/gnome/home umount.nfs4: /net/gnome/home: device is busy umount.nfs4: /net/gnome/home: device is busy # umount -f /net/gnome/home umount2: Device or resource busy umount.nfs4: /net/gnome/home: device is busy umount2: Device or resource busy umount.nfs4: /net/gnome/home: device is busy # umount -f /net/gnome umount2: Device or resource busy umount.nfs4: /net/gnome: device is busy umount2: Device or resource busy umount.nfs4: /net/gnome: device is busy At this point, there are two ways: 1. try to find and kill all processes which are using the mountpoint. But in almost all cases it is not possible since there is at least one process which is in D state and unkillable, so we proceed to variant 2: 2. echo b > /proc/sysrq-trigger or something of this sort, since it will not be able umount / anyway. Note that even if 1. succeed, the system is unusable anyway, since it is here to service users. So it is simpler and faster to proceed to 2. stright away. What can be done to stop the "Stale NFS handle" situation from happening -- except of stopping rebooting the server? At least with nfs3 it has been almost solved (almost, because from time to time it still happens even with nfs3, leading to the same issue). Thanks! /mjt -- 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
