Mountd, why not use the '-S' flag by default

[Mark Schouten]

Hi,


I'm using a FreeBSD nfs-server as storage for my Linux KVM-based VPS-platform. The images reside on the NFS-server.


I'm been noticing errors in my VPS disks when running 'zfs set sharenfs=XYZ', probably because of reloads of mountd.


While trying to debug that, I ran acros this message in mountd(8):

     -S      Tell mountd to suspend/resume execution of the nfsd threads when-
             ever the exports list is being reloaded.  This avoids intermit-
             tent access errors for clients that do NFS RPCs while the exports
             are being reloaded, but introduces a delay in RPC response while
             the reload is in progress.  If mountd crashes while an exports
             load is in progress, mountd must be restarted to get the nfsd
             threads running again, if this option is used.


I can't think of a reason why you wouldn't want to use -S by default.. An '/etc/rc.d/mountd reload' without it causes even my running Bonnie on a normal NFS-share (not via a diskimage) to stop with 'input/output error'. Can someone enlighten me with the drawbacks of using -S ?


Met vriendelijke groeten,

-- 
Kerio Operator in de Cloud? https://www.kerioindecloud.nl/
Mark Schouten  | Tuxis Internet Engineering
KvK: 61527076 | http://www.tuxis.nl/
T: 0318 200208 | info at tuxis.nl
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