NFSROOT, LVM2, et al...

Ian Molton spyro at
Thu Jul 1 17:45:02 PDT 2004

Well its safe to say that my NFS root experiment has been a total success...

I now have a Duron 1800XP+ (266FSB) with 1GB RAM and (tomorrow anyhow) 240GB of harddisc.
LFS unstable.

the drive is split into 4 partitions - root, swap, spare, and the remaining 100GB or so managed by LVM2 and I've tried (successfully) to resize the volume using five test partitions. the next drive goes in tomorrow (hopefully) and will be added to the LVM2 volume.

Having installed the OS, and tested LVM2, I flattened the test volumes and created the real volumes, with ext3, and copied my machines FS onto it.

next came NFS (tcpwrappers, portmap, and nfs-utils) on the server.

the ext3 volume has a root filesystem in a subdirectory on it, which is exported with the async and no_root_squash properties.

the client mounts this, and boots, the minor modifications to the bootscripts being:

a) load portmap early on  (needed for nfs locking)
b) dont remount root rw, remount it rw,lock (to enable nfs locking).
c) dont take down the network interfaces on shutdown (like, duh...)

altered /etc/fstab to reflect the real root fs and remove swap (I dont fancy swap over NFS and I have plenty of RAM (256MB on the client))

I honestly couldnt tell it was running on NFS speed wise with the exception of the very first couple of scripts (pulling in a lot of pages) and loading mozilla (about 2 seconds slower).

Compiling a kernel was a mere 3 seconds slower than when I was using a local disc (55MB/sec seagate barracuda w/ 8MB cache, so no slouch).

the key to speed is to use an async NFS export. sync is slow as hell. and yes, my server is on a UPS ;-)

More information about the lfs-chat mailing list