4 ms·

In my experience, the quality of NFS client implementations varies significantly between different operating systems. We made _heavy_ use of NFS for home direc

In my experience, the quality of NFS client implementations varies significantly between different operating systems. We made _heavy_ use of NFS for home directories and application backing stores at the University where I used to work, and it was a very good experience -- but this was on Solaris 10 (and later, OpenSolaris) machines. We had heavy NFS client use on many multi-user machines (shell servers, Sun Ray servers, etc) and didn't see reliability problems. On the odd occasion that we needed to reboot the file server for updates, clients would pause and then resume promptly after the server rebooted. Towards the end of my tenure there, I gave a Linux desktop a try. The NFS experience was amazingly bad by comparison; lots of issues with locking, with becoming disconnected (often until a reboot) from NFS servers, odd performance issues, reliability issues with the automounter, etc. In the last few months I have tried the NFS client on my current Linux desktop again, thinking things might have improved -- they have, I guess, but not by much. It's still pretty easy for the client to get into a hung state if there's too much packet loss, or if the file server reboots, or whatever. I have to imagine that not enough people are really using Linux NFS clients in anger to drive fixing the issues with it. There is often no escape from the Quality Death Spiral.

romeisendcoming 8y ago
NFS requires long admin experience and tuning for each use case. The only comment I can agree with you on is that the linux automounter is lackluster. We used BSD amd for many years with good success.
- jabl 8y ago
  > NFS requires long admin experience and tuning for each use case. Depends on what you're going to do with it. For something like sharing home directories, it works well enough. The defaults are usually pretty decent. There's unfortunately a lot of obsolete NFS tuning advice hanging around on the internet that seems to get cargo culted over and over again. Like the advice to set some specific rsize/wsize settings because the default is too small, oblivious to the fact that the NFS protocol allows the client and server to negotiate maximum sizes, and at least the Linux client and server have taken advantage of this negotiation mechanism for the past 2 decades or so.
  - romeisendcoming 8y ago
    Well enough isn't good enough for production. Having worked in high volume, highly available environments for years soho scenarios are not good examples. Real world issues with complex NFS environments (mixed nfs3/4 + krb5p and multiple OS'es + automounters) or pNFS and gluster require more than tuning mount options. Tuning NFS for a latency averse and throughput intensive application operating on large netcdf and hdf5 file hierarchies is a worthy example.
    - jabl 8y ago
      > Well enough isn't good enough for production. How informative. > Having worked in high volume, highly available environments for years soho scenarios are not good examples. FWIW, I wasn't talking about SOHO. At least in my experience, defaults work well for home & shared work dirs for O(10k) users (not all simultaneously active, though). HA is a pain, though, if you want to DIY, I'll grant you that. > Real world issues with complex NFS environments (mixed nfs3/4 + krb5p and multiple OS'es + automounters) Complex? Sounds like a pretty standard NFS environment. > or pNFS and gluster require more than tuning mount options. Yeah, no personal experience there. What did you have to do there? We did have a clustered NFS appliance for HPC use a decade or so ago. People like to complain how Lustre is a beast to run, but IME Lustre has been smooth sailing compared to the grief that POS gave us. But that wasn't really the fault of the NFS protocol per se, it was just the architecture as well as the implementation of that appliance was crap, particularly so for HPC.
      - romeisendcoming 8y ago
        * routine buffer tweak is soho speak. * defaults don't work esp in mixed nfs 3/4 on linux across mixed 1/10 gb segment subnet boundaries. Try and get back to me. You will DOS your file service. * krb5p standard? First I've heard of it. FreeBSD won't do krb5p at nfs4 vanilla via linux nfs server. * Would never do it again. gluster is a shit storm of problems but nice when it works.

romeisendcoming 8y ago

NFS requires long admin experience and tuning for each use case. The only comment I can agree with you on is that the linux automounter is lackluster. We used BSD amd for many years with good success.

jabl 8y ago
> NFS requires long admin experience and tuning for each use case. Depends on what you're going to do with it. For something like sharing home directories, it works well enough. The defaults are usually pretty decent. There's unfortunately a lot of obsolete NFS tuning advice hanging around on the internet that seems to get cargo culted over and over again. Like the advice to set some specific rsize/wsize settings because the default is too small, oblivious to the fact that the NFS protocol allows the client and server to negotiate maximum sizes, and at least the Linux client and server have taken advantage of this negotiation mechanism for the past 2 decades or so.
- romeisendcoming 8y ago
  Well enough isn't good enough for production. Having worked in high volume, highly available environments for years soho scenarios are not good examples. Real world issues with complex NFS environments (mixed nfs3/4 + krb5p and multiple OS'es + automounters) or pNFS and gluster require more than tuning mount options. Tuning NFS for a latency averse and throughput intensive application operating on large netcdf and hdf5 file hierarchies is a worthy example.
  - jabl 8y ago
    > Well enough isn't good enough for production. How informative. > Having worked in high volume, highly available environments for years soho scenarios are not good examples. FWIW, I wasn't talking about SOHO. At least in my experience, defaults work well for home & shared work dirs for O(10k) users (not all simultaneously active, though). HA is a pain, though, if you want to DIY, I'll grant you that. > Real world issues with complex NFS environments (mixed nfs3/4 + krb5p and multiple OS'es + automounters) Complex? Sounds like a pretty standard NFS environment. > or pNFS and gluster require more than tuning mount options. Yeah, no personal experience there. What did you have to do there? We did have a clustered NFS appliance for HPC use a decade or so ago. People like to complain how Lustre is a beast to run, but IME Lustre has been smooth sailing compared to the grief that POS gave us. But that wasn't really the fault of the NFS protocol per se, it was just the architecture as well as the implementation of that appliance was crap, particularly so for HPC.
    - romeisendcoming 8y ago
      * routine buffer tweak is soho speak. * defaults don't work esp in mixed nfs 3/4 on linux across mixed 1/10 gb segment subnet boundaries. Try and get back to me. You will DOS your file service. * krb5p standard? First I've heard of it. FreeBSD won't do krb5p at nfs4 vanilla via linux nfs server. * Would never do it again. gluster is a shit storm of problems but nice when it works.