* root file system mounted via NFS - retry? @ 2006-04-12 12:35 Randy Smith 2006-04-12 12:40 ` Jarno Manninen 2006-04-12 12:50 ` Brent Cook 0 siblings, 2 replies; 4+ messages in thread From: Randy Smith @ 2006-04-12 12:35 UTC (permalink / raw) To: linuxppc-embedded Hello, I have a general question regarding having a root file system mounted via NFS. Our system consists of a linux PC that acts as the NFS server and two embedded ppc boards running linux that mount their file systems via NFS. The problem is that the embedded boards boot much faster than the PC, and when they attempt to mount the root file system, the NFS server is not up yet. The embedded boards hang and it takes quite a long time before the watchdog timer reboots them. The next time round, they come up just fine. What I would like for them to do is keep trying until the NFS server appears and then continue to boot. We are running DENX's ELDK 2.4.25 kernel on the ppc boards and I know that for some linux releases, one may add values for timeo and retrans on the boot command line in the NFSROOT= command. Can anyone tell me if they are valid for this release of the kernel? Or if there is another way to accomplish this? Thanks, -Randy Smith Software Engineer ImageMap, Inc. ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: root file system mounted via NFS - retry? 2006-04-12 12:35 root file system mounted via NFS - retry? Randy Smith @ 2006-04-12 12:40 ` Jarno Manninen 2006-04-12 12:50 ` Brent Cook 1 sibling, 0 replies; 4+ messages in thread From: Jarno Manninen @ 2006-04-12 12:40 UTC (permalink / raw) To: linuxppc-embedded On Wednesday 12 April 2006 15:35, Randy Smith wrote: Hi, If your system configuration is static why not just sleep in the bootloader for a while? U-boot has sleep command. - Jarno > Hello, > > I have a general question regarding having a root file system mounted > via NFS. Our system consists of a linux PC that acts as the NFS server > and two embedded ppc boards running linux that mount their file systems > via NFS. The problem is that the embedded boards boot much faster than > the PC, and when they attempt to mount the root file system, the NFS > server is not up yet. The embedded boards hang and it takes quite a > long time before the watchdog timer reboots them. The next time round, > they come up just fine. > What I would like for them to do is keep trying until the NFS server > appears and then continue to boot. > > We are running DENX's ELDK 2.4.25 kernel on the ppc boards and I know > that for some linux releases, one may add values for timeo and retrans > on the boot command line in the NFSROOT= command. Can anyone tell me if > they are valid for this release of the kernel? Or if there is another > way to accomplish this? > > Thanks, > > -Randy Smith > Software Engineer > ImageMap, Inc. > > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: root file system mounted via NFS - retry? 2006-04-12 12:35 root file system mounted via NFS - retry? Randy Smith 2006-04-12 12:40 ` Jarno Manninen @ 2006-04-12 12:50 ` Brent Cook 2006-04-12 14:01 ` Randy Smith 1 sibling, 1 reply; 4+ messages in thread From: Brent Cook @ 2006-04-12 12:50 UTC (permalink / raw) To: linuxppc-embedded On Wednesday 12 April 2006 07:35, Randy Smith wrote: > Hello, > > I have a general question regarding having a root file system mounted > via NFS. Our system consists of a linux PC that acts as the NFS server > and two embedded ppc boards running linux that mount their file systems > via NFS. The problem is that the embedded boards boot much faster than > the PC, and when they attempt to mount the root file system, the NFS > server is not up yet. The embedded boards hang and it takes quite a > long time before the watchdog timer reboots them. The next time round, > they come up just fine. > What I would like for them to do is keep trying until the NFS server > appears and then continue to boot. > Sorry to try the obvious, but could you make the firmware's auto-boot timeout longer? I know that u-boot and several others support this. Also, you could try, instead of mounting root NFS directly from the kernel, an initrd or embedding an initramfs that does the mount using a script. They you could retry as much as you wanted without having to teach the kernel anything. Or, just hook up some GPIOs from your PC to the reset lines on those PPC's. Then reset them once your PC is up. Or rather than running the PPC kernel from flash, tftp it to RAM from your PC - that way your PPCs can't even load the kernel until the PC is up (assuming your firmware knows how to do this and handles faults gracefully.) - Brent ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: root file system mounted via NFS - retry? 2006-04-12 12:50 ` Brent Cook @ 2006-04-12 14:01 ` Randy Smith 0 siblings, 0 replies; 4+ messages in thread From: Randy Smith @ 2006-04-12 14:01 UTC (permalink / raw) Cc: linuxppc-embedded Brent Cook wrote: > On Wednesday 12 April 2006 07:35, Randy Smith wrote: > >> Hello, >> >> I have a general question regarding having a root file system mounted >> via NFS. Our system consists of a linux PC that acts as the NFS server >> and two embedded ppc boards running linux that mount their file systems >> via NFS. The problem is that the embedded boards boot much faster than >> the PC, and when they attempt to mount the root file system, the NFS >> server is not up yet. The embedded boards hang and it takes quite a >> long time before the watchdog timer reboots them. The next time round, >> they come up just fine. >> What I would like for them to do is keep trying until the NFS server >> appears and then continue to boot. >> >> > > Sorry to try the obvious, but could you make the firmware's auto-boot timeout > longer? I know that u-boot and several others support this. > We are using U-boot and yes, I can set the delay. This does work around the problem, but I was hoping for a more 'elegant' solution. > Also, you could try, instead of mounting root NFS directly from the kernel, an > initrd or embedding an initramfs that does the mount using a script. They you > could retry as much as you wanted without having to teach the kernel > anything. > Another possibility. Thanks! > Or, just hook up some GPIOs from your PC to the reset lines on those PPC's. > Then reset them once your PC is up. > This is not possible with our current design, but it would solve the problem. > Or rather than running the PPC kernel from flash, tftp it to RAM from your > PC - that way your PPCs can't even load the kernel until the PC is up > (assuming your firmware knows how to do this and handles faults gracefully.) > The way our system was initially designed, it worked this way. We are modifying the design to remove the dependency on NFS by embedding the boot loader, kernel and root file system on the flash. We aren't quite there yet so in the meantime we moved the kernel to the flash and now we are seeing this problem. And in fact, the problem may not be as I described. I have been running some other tests and I am getting indications that the problem may be in the hardware that our ppc boards are talking to. I stripped a ppc board down to just the computer part and hooked up a serial line to it. Cold-boot and the stripped down ppc reached the mount nfs part and waited for a little while, and then continued on, so I am discounting the theory that the NFS mount was failing due to timeout. The other ppc board hung with the same behavior, but I cannot put a serial line on it. The question remains though, does the NFS timeo and retrans parameters on the nfsroot kernel command line apply to the 2.4.25 kernel supplied by DENX' ELDK? Thanks, -Randy > - Brent > > ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2006-04-12 14:06 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2006-04-12 12:35 root file system mounted via NFS - retry? Randy Smith 2006-04-12 12:40 ` Jarno Manninen 2006-04-12 12:50 ` Brent Cook 2006-04-12 14:01 ` Randy Smith
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