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soc:2009:pravin:journal:fedora11bko [2009/07/06 15:16]
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soc:2009:pravin:journal:fedora11bko [2009/07/27 05:35] (current)
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 EXT4-fs error (device dm-0): __ext4_get_inode_loc:​ unable to read inode block - inode=9642, block=827 EXT4-fs error (device dm-0): __ext4_get_inode_loc:​ unable to read inode block - inode=9642, block=827
 </​code>​ </​code>​
 +
 +There is one warning regarding device dm-0 while boot time, I am not sure if that is relevant to this error, but I will anyway document it here
 +<​code>​
 +JDB: barrier-based sync failed on dm-0:8 - disabling barriers
 +</​code>​
 +
  
 and following are the logs from apache2 server which was serving this iso image. and following are the logs from apache2 server which was serving this iso image.
Line 98: Line 104:
 </​code>​ </​code>​
 I am not sure if they will make any sense, but I have put them for reference. I am not sure if they will make any sense, but I have put them for reference.
 +
 +===== Attempt-3 =====
 +I wanted to remove ''/​etc/​rc3.d/​S80sendmail'',​ but I am not able to delete it. It says it is read-only filesystem.
 +But when I run mount command, it shows the filesystem in ''​rw''​ mode.  Following are the command I tried.
 +<​code>​
 +# mount
 +/dev/root on / type ext4 (rw,​noatime)
 +proc on /proc type proc (rw)
 +/sys on /sys type sysfs (rw)
 +udev on /dev type tmpfs (rw,​mode=0755)
 +/dev/pts on /dev/pts type devpts (rw,​gid=5,​mode=620)
 +
 +# rm /​sysroot/​etc/​rc3.d/​S80sendmail
 +rm: cannot remove '/​sysroot/​etc/​rc3.d/​S80sendmail'​ : Read-only file system
 +
 +# mount / -o remount,rw
 +
 +# rm /​sysroot/​etc/​rc3.d/​S80sendmail
 +rm: cannot remove '/​sysroot/​etc/​rc3.d/​S80sendmail'​ : Read-only file system
 +
 +</​code>​
  
 ====== What is working? ​ ====== ====== What is working? ​ ======
 Single user mode is working fine.  so user gets shell where he can do all he wants Single user mode is working fine.  so user gets shell where he can do all he wants
  
 +
 +====== Fedora 11 live over NFS ======
 +Trying to see if Fedora 11 live can boot over NFS.\\
 +The reasoning behind this experimentation is that, if it works over NFS then it may help in locating the problem.
 +
 +
 +==== Testing NFS setup ====
 +Exported the "/​var/​www"​ ( because it contains all the ISO images) over NFS.  Following is the excerpt from ''/​etc/​exports''​
 +<​code>​
 +/var/www *(ro,async)
 +</​code>​
 +This NFS volume does get mounted properly on local machine.
 +<​code>​
 +sudo mount 192.168.111.11:/​var/​www mpoint
 +$ mount
 +192.168.111.11:/​var/​www on /​home/​pravin/​Etherboot/​mpoint type nfs (rw,​addr=192.168.111.11)
 +</​code>​
 +
 +==== Testing the NFS mount from virtualization ====
 +Fedora 11 live cd was booted with virtualBox. The network was working and even the host machine was accissible as the URL http://​192.168.111.11 did correctly resolved to Host website.\\
 +But NFS mount failed with following error.
 +<​code>​
 +# mount 192.168.111.11:/​var/​www /​home/​liveuser/​mpoint/​
 +mount.nfs: access denied by server while mounting 192.168.111.11:/​var/​www
 +</​code>​
 +Why would this fail if mounting from localhost is working fine?
 +
 +Got help from rwrc, and fixed the problem.\\
 +It seems one more option has to be added to export options ''​insecure'',​ restating the explanation given by rwcr
 +<​code>​
 +rwcr: Try making it /var/www *(ro,​async,​insecure)
 +rwcr: Linux generally requires NFS requests to come from privileged ports, and the Fedora livecd might be using a nonstandard NFS mounter that doesn'​t do that.
 +</​code>​
 +
 +===== Next step : mount NFS partition from initramfs =====
 +Debian uses special program called ''​nfsmount''​ for NFS mounting at boot time, I will try out both. The mount command and nfsmount utility.\\
 +Also, the kernel module be needed.
 +Following modules and executable ''/​sbin/​mount.nfs''​ was needed for NFS to work
 +   - sunrpc.ko
 +   - lockd.ko
 +   - auth_rpcgss.ko
 +   - nfs_acl.ko
 +   - nfs.ko
 +In addition to this, I had to pass option ''​-o nolock''​ for mount to work without problems
 +<​code>​
 +mount "​${NFS_PATH} /iso -o nolock"​
 +mount /​iso/​Fedora-11-i686-Live.iso /sysroot -o loop -o ro
 +</​code>​
 +
 +NFS works fine in run level 3. also one can start the GUI with ''​startx''​ after logging in as ''​root''​ from multiuser prompt.\\
 +The only issue with NFS_Fedora is that ''​plymountd''​ still creates a problem and is disabled and it somehow stops GUI coming up automatically.\\
 +So, the user need to login in run-level 3 and then do the ''​startx''​
 +
 +
 +==== HTTPFS improvement ====
 +Some progress has been done on HTTPFS front also.  Till now, all the tests of booting over HTTPFS were done using ''​qemu''​ which is inherently slow as it is emulation.
 +When same tests were run on vmware, which is much faster, errors started comming after runlevel - 3 login prompt\\
 +Following are the errors, which are quite same as those errors which use to come around sendmail daemon before.
 +
 +<​code>​
 +# startx
 +-bash: /​usr/​bin/​startx:​ Input/​output error
 +
 +# top
 +top : error while loading shared libraries: /​lib/​libncursesw.so.5:​ cannot read file data: Input/​output error
 +
 +EXT4-fs error (device dm-0): ext4_find_entry:​ reading directory #10651 offset 0
 +</​code>​
 +With this observation,​ we can claim that errors are thrown because there is delay in response from fuse.  The ext4-fs is giving up because of this delay.\\
 +Now, I need to find a way to increase the tolerance for this delay.
 +
 +
 +===== Removing plymouth =====
 +As marc has suggested, remove ''​plymount''​ from original iso, and see if it works without plymount.
 +If it doesn'​t then blame can be surely put on ''​plymount''​ and not the network related complications. \\
 +
 +==== Modifying ISO ====
 +Now, the question is, how to add new initramfs into ISO and still keep it bootable?\\
 +From Remastering Knoppix Howto, following is the command which works for knoppix
 +<​code>​
 +mkisofs -pad -l -r -J -v -V "​KNOPPIX"​ -no-emul-boot -boot-load-size 4 \
 +   ​-boot-info-table -b boot/​isolinux/​isolinux.bin -c boot/​isolinux/​boot.cat \
 +   ​-hide-rr-moved -o /​mnt/​hda1/​knx/​knoppix.iso /​mnt/​hda1/​knx/​master
 +</​code>​
 +
 +and I need to modify it, so that it will work for fedora.
 +
 +<​code>​
 +mkisofs -pad -l -r -J -v -V "​Fedora-11-i686-Live"​ -no-emul-boot -boot-load-size 4 \
 +   ​-boot-info-table -b isolinux/​isolinux.bin -c isolinux/​boot.cat \
 +   ​-hide-rr-moved -o /​var/​www/​iso/​fedora_11.iso /​home/​pravin/​Etherboot/​git/​BKO.git/​pxeknife/​red_hat/​fedora_11_live_cd/​newfedora
 +</​code>​
 +===== running startx from single user mode =====
 +Tried an experiment of running ''​startx''​ from single user mode and see if it works.\\
 +Well it did not worked atall.
 +
 +===== Problem Found =====
 +With help of andyTim, the cause of problem has been located.\\
 +The ''​network''​ and ''​NetworkManager''​ do restart the networking which breaks the existing HTTPFS mount.
 +
 +
 +===== Solution =====
 +The temporary solution tried is delete both of following files
 +  - ''/​etc/​init.d/​network''​
 +  - ''/​etc/​init.d/​NetworkManager''​
 +So, user has to first boot into single user mode, delete above files,
 +and then boot into runlevel 5.
  
  

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