[wellylug] Debian & NFS

David Antliff dave.antliff at paradise.net.nz
Wed Jul 6 18:45:40 NZST 2005


Hi everyone,

Does anyone know what the Real Deal is with the *two* NFS servers in 
Debian? There's nfs-user-server and nfs-kernel server. Anyway, I used to 
use nfs-user-server for a while until I discovered some rather nasty 
synchronisation issues and switched to the kernel server. This worked 
great for several years until I had the age-old NFS problem:

User xyz has uid 1000 on hostA, but uid 1001 on hostB. HostA exports a 
directory and user xyz on hostB can't access it properly because of the 
uid mismatch. Note that 'uid=value' is not supported for NFS mounts.

Rather than matching up the uids manually (or heaven forbid, with NIS) I 
decided to investigate the map_static option (for /etc/exports). After a 
bit of messing around and searching source and string tables I was able to 
determine that this option is not supported by nfs-kernel-server and 
nicely supported by nfs-user-server. So I switched back to 
nfs-user-server.

No problems there as far as I can tell. Until today.

Oh, nfs-user-server imposes a 2GiB limit on file size. Dang. There goes my 
recent backups. nfs-kernel-server doesn't impose this limit.

Anyway, I haven't really seen this nfs-user-server in other distros like 
Gentoo so I'm wondering what the deal with it is. Google doesn't reveal 
much and I really can't tell which is the 'preferred option'. Both seem to 
support different feature sets and the stability is quite different too it 
would seem.

So, would anyone kindly shed some light on this whole situation please? 
I'd like to get the stability and (relative) robustness of the 
nfs-kernel-server (as I perceive it) but I'd also like the uid mapping 
feature of the nfs-user-server. Cake and eat it territory.

Or perhaps I'll just switch back to the kernel server and take the 'hit' 
and sync up the uids.

Gentoo has something called nfsidmap "NFSv4 ID <-> name mapping library" 
- is anyone using this?

http://www.citi.umich.edu/projects/nfsv4/linux/

Does Samba still have a 2GiB file size limit?

Are there any other alternatives to NFS worth looking at?

-- 
David.




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