Initramfs/tmpfs and df issue.

Apr 27, 2005 0 Replies

Hi,


I have an issue with the df command and my initramfs.


First let me explain my system boot process (could be related to a bad stuff I did, anyway any suggestions are welcome):


Linux kernel 2.6.11 with 99% drivers compiled as module as I try to keep my kernel as small as possible (still not enough):



# ls -la /boot/Kernel-2.6.11


-rw-r--r-- 1 root root 764463 Mar 3 00:30 Kernel-2.6.11


Then I have created my initramfs cpio archive with all the stuff I need:



/bin and /sbin for some binaries (busybox, udev).



/libs for the .so of the bins above



# ls -la /dev



drwxr-xr-x 2 root root 4096 Jan 30 18:14 .



drwxr-xr-x 6 root root 4096 Apr 27 18:36 ..



crw--w--w- 1 root tty 5, 1 Jan 20 09:11 console



brw-rw---- 1 root disk 3, 0 Jan 21 12:35 hda



brw-rw---- 1 root disk 3, 1 Jan 21 12:35 hda1



brw-rw---- 1 root disk 3, 2 Jan 20 10:10 hda2



brw-rw---- 1 root disk 1, 0 Jan 20 10:10 ram0


And a /init program which :



mount /proc and /sys



create and populate the rootfs with some applications./.



and launch /sbin/init at the end to finalize the job.


My grub bootloader menu/lst look like :



title INITRAMFS 2.6.11



root (hd0,1)



kernel /boot/Kernel-2.6.11 ramdisk_size=32768 root=/dev/ram0 rw idebus=33



initrd /boot/Initramfs


Then my system boot and run without any problem, except the df command !!!


Busybox df (same with an other bin) do not work on my tmpfs mount point :



# df



Filesystem 1k-blocks Used Available Use% Mounted on


/opt has been populated but df do not see anything :



# df /opt



Filesystem 1k-blocks Used Available Use% Mounted on



tmpfs 0 0 0 0% /opt


Here is my /etc/fstab :



proc /proc proc defaults 0 0



tmpfs /var tmpfs size=64m 0 0



tmpfs /tmp tmpfs size=32m 0 0



tmpfs /opt tmpfs size=64m 0 0



sysfs /sys sysfs defaults 0 0


If I mount an ext2 FS from the HDD then if work fine:



# df



Filesystem 1k-blocks Used Available Use% Mounted on



/dev/hda2 62959208 5026040 54735032 8% /mnt


I do not have a /etc/mtab file but it is the same if I create one within the initramfs init prog, same also if I create a link (/etc/mtab -> /proc/mounts).


Here are the results of mount and cat /proc/mounts :



# mount



none on /proc type proc (rw,nodiratime)



none on /sys type sysfs (rw)



none on /dev type ramfs (rw)



tmpfs on /tmp type tmpfs (rw)



tmpfs on /var type tmpfs (rw)



tmpfs on /opt type tmpfs (rw)


# cat /proc/mounts



rootfs / rootfs rw 0 0



none /proc proc rw,nodiratime 0 0



none /sys sysfs rw 0 0



none /dev ramfs rw 0 0



tmpfs /tmp tmpfs rw 0 0



tmpfs /var tmpfs rw 0 0



tmpfs /opt tmpfs rw 0 0


An other issue is (maybe related) if I do a mount -a it will mount the tmpfs again and on top of the others without any complains (/proc/mounts entries are duplicated.).


Any help or ideas will be appreciated as I my really stuck on this point :-<


Thank you.



Yacine.


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