Tomas M schrieb: > Hello Patrick. > Here is the explanation you're looking for, I hope. > > If you use 'mount' command to list all mounted filesystems, it only > reads /etc/mtab and it prints the lines from it. It doesn't care about > the filesystems which are actually mounted, it only cares about > /etc/mtab. > > If you use -n option while mounting (which means: don't update mtab) > or if you try to get the list of mounted filesystems _after_ > pivot_root/chroot, then 'mount' will not show you anything as > /etc/mtab is empty. > > You'll have to 'cat /proc/mounts', which is always updated by kernel. > > The text above should answer your first question. Now regarding > /etc/fstab: this file doesn't need to be updated, but it may be > sometimes useful to do it. > > The /etc/fstab file is usually used only for 'mount' command, as a > help file for the case if you don't use full mount command. > > from man: The file fstab contains descriptive information about the > various systems. fstab is only read by programs, and not written; it > is the duty of the system administrator (or a Live CD startup script) > to properly create and maintain this file. > > If you have entries in fstab, then you can use (for example): > > mount /mnt/diskC > > command, and it will work. If you don't have this mountpoint in fstab, > mount will not work, it will complain about missing arguments. > > So in general, you don't need to update /etc/fstab if you are not > using incomplete mount commands, and if you're sure any software needs > fstab. > > Some programs may require a fstab entry in order to mount the > filesystem, including root filesystem /, so Live CDs usually create a > dummy entry for root partition in fstab, something like 'aufs / aufs > defaults 0 0', or 'tmpfs / tmpfs defaults 0 0'. > > Moreover Live CDs (like Slax) create new fstab file automatically, > depending on what filesystems and partitions are detected. It makes > things easier but is not required. > > > Tomas M > linux-live.org Thanks for that great explanation! :-) .. now my next initial question is, how to use mount.aufs .. I read the source tho, but I dont really get how to use it .. as a substitute of mount or in conjunction with it? I also dont know much about it's whole capability and syntax, so could you please enlighten me? :)
regards, Patrick > > > Patrick wrote: >> [EMAIL PROTECTED] schrieb: >>> Hello Patrick, >>> >>> Patrick: >>> >>>> Now my question is .. do I have to adapt /etc/fstab at all? What >>>> also concerns me, is that 'mount' does not show any unionfs/aufs >>>> related stuff (I run-init'ed into the unionfs tho) .. is that >>>> normal? I am asking because common livecd's (knoppix, grml, etc.) >>>> always come up with a unionfs/aufs listed in the output of 'mount'. >>>> >>> mount(8) shows /etc/mtab file. >>> If the file didn't exist and you didn't install /sbin/mount.aufs, or >>> you >>> used -n option to you mount(8), then you need to create /etc/mtab >>> manually. >>> >> Err, I used -n and /etc/mtab exists. I dont get at all, what you're >> refering to. My initial question was, wether /etc/fstab needs >> adaption, since mount does not list anything unionfs related. But >> still it works fine since I run-init (switch_root - pivot_root with >> initrd) into the unified filesystems. >>> I suggest you to execute this command just after mounting aufs. >>> # cp /proc/mounts /etc/mtab >>> Additionally, if you use 'mount -o remount,... /your/aufs' later, it is >>> recommended to install mount.aufs. >>> >>> Current aufs produces all branch paths to /proc/mounts. >>> Therefore if you have a lot of branches, you may meet a limitation of a >>> page which is usually 4k bytes. mount(8), /etc/mtab, /proc/mounts have >>> this limitation. >>> I will try sysfs and modify aufs entry in /proc/mounts in a few weeks. >>> >>> >>> Junjiro Okajima >>> >>> >> As I said .. what I do is mount the rootfs .. then mount a new tmpfs >> .. then mount the unionfs (tmpfs overlays rootfs) .. then I run-init >> into the unified filesystems. Still mount doesnt show any >> unionfs/aufs related stuff (I tried with aufs and unionfs - same >> behavior). 'mount''s output is the same as if I wouldnt have used a >> unionfs at all .. (I also didnt change /etc/fstab, since I dont know >> wether it's required)... So what is wrong .. or to be more specific >> what is not wrong with it? :) >> >> >> regards, >> Patrick >> >> ------------------------------------------------------------------------- >> >> Take Surveys. Earn Cash. Influence the Future of IT >> Join SourceForge.net's Techsay panel and you'll get the chance to >> share your >> opinions on IT & business topics through brief surveys-and earn cash >> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV >> >> > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
