History of Computer Problem-Solution (Open) (No. 14)

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• Go to Computer Problem-Solution (Open).
  • 1 (2009-04-26 (Sun) 01:23:07)
  • 2 (2009-04-26 (Sun) 01:23:59)
  • 3 (2009-05-08 (Fri) 08:39:27)
  • 4 (2009-05-18 (Mon) 21:55:43)
  • 5 (2009-06-01 (Mon) 21:39:07)
  • 6 (2009-06-02 (Tue) 10:21:13)
  • 7 (2009-06-04 (Thu) 00:16:54)
  • 8 (2009-07-02 (Thu) 12:35:59)
  • 9 (2009-07-02 (Thu) 21:46:59)
  • 10 (2009-07-17 (Fri) 16:01:58)
  • 11 (2009-09-09 (Wed) 13:12:19)
  • 12 (2009-10-10 (Sat) 13:06:29)
  • 13 (2010-01-06 (Wed) 22:37:13)
  • 14 (2010-01-13 (Wed) 23:18:23)
  • 15 (2010-01-17 (Sun) 15:41:21)
  • 16 (2010-01-19 (Tue) 16:12:51)
  • 17 (2010-04-29 (Thu) 15:24:51)
  • 18 (2012-03-29 (Thu) 10:42:18)
  • 19 (2012-08-29 (Wed) 17:46:04)
  • 20 (2012-09-25 (Tue) 17:01:48)
  • 21 (2012-09-26 (Wed) 12:18:33)
  • 22 (2012-10-02 (Tue) 17:01:00)
  • 23 (2013-06-03 (Mon) 17:13:46)
  • 24 (2013-06-05 (Wed) 14:43:13)
  • 25 (2013-08-26 (Mon) 10:20:51)
  • 26 (2013-10-24 (Thu) 09:04:54)
  • 27 (2014-01-17 (Fri) 18:53:28)
  • 28 (2014-07-24 (Thu) 11:35:12)
  • 29 (2014-08-04 (Mon) 10:01:23)
  • 30 (2014-08-05 (Tue) 10:03:57)
  • 31 (2014-08-05 (Tue) 13:01:22)
  • 32 (2014-08-13 (Wed) 10:14:22)
  • 33 (2014-08-14 (Thu) 05:43:40)
  • 34 (2014-08-18 (Mon) 11:43:55)
  • 35 (2014-08-19 (Tue) 12:27:17)
  • 36 (2014-08-22 (Fri) 15:15:39)
  • 37 (2014-08-22 (Fri) 15:53:33)
  • 38 (2014-10-14 (Tue) 17:07:51)
  • 39 (2014-10-17 (Fri) 14:16:07)
  • 40 (2015-08-06 (Thu) 15:02:09)
  • 41 (2016-03-10 (Thu) 11:11:59)

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This is a page of "How to" solve some computer problems that may happen.

P = problem; S = solution

P: (2010.1.13) The problem of 2010.1.6 is solved but response is slow.†

S: The problem is due to the fact that /etc/mtab is on root (not snapshot)†

Since we do not know what is the process of mount the file. we can not change mtab to snapshot. For a moment, we force mount /home1 and /rsaito on /tmp/home1, /tmp/rsaito

/etc/rc5.d/S28autofs stop
mkdir /tmp/home1
mkdir /tmp/rsaito
mount -n 192.168.2.100:/home1 /tmp/home1
mount -n 192.168.2.100:/rsaito /tmp/rsaito
df

/rsaito/bin/pxe-mount

P: (2010.1.6) /rsaito is not automountd on PXE client.†

S: edit and add flexS:/rsaito information on†

tube30:/nfsboot/root/etc/mtab

P: (2009.10.10) Gnorm logout is slow for Xming etc.†

This is a firewall problem of windows.

S: Open port 16001 tcp†

control panel -> firewall -> add new port ->

Name Esound
Port 16001
     TCP

P: (2009.07.17) Load average of FLEX is very high.†

This is due to mounting problem again (mount NFS). After checking mount status, it is found that a network harddisk was not unmounted nicely before turning off.

S: Re-mount (turn on) the harddisk, and do some safety procedure.†

• check mount status:

  # mount

• umount once (assuming mount point is /mnt/backup):

  # umount -f /mnt/backup

• synchronize several times:

  # sync
  # sync
  # sync

• check df or mount status again
• if the harddisk has been nicely unmounted, then it is safe to turn it off.

P: (2009.07.02 night, 9:30 PM) Flex problem again†

I (Nugraha) could not login to flex webmail even using web browser:

ERROR: Could not complete request.

and I could not login either to flex work account (ssh).

S: ?†

P: (2009.07.02) Flex is unstable for logining or e-mails.†

S: mount to tube:/home1-old was not allowed any more.†

comment out one line in /etc/auto.misc 
# home1    172.17.4.134:/home1-old

./S28autofs forcerestart

I also delete in /etc/exports 

the requests from 172.17.4.184 (nuguraha) 172.17.4.188 (mahabubu)
and 172.17.4.127 (furu).

exportfs -a

we also need to restart nfs
/etc/rc5.d/S60nfs restart

P: (2009.06.03) Today we were failed to run ether-wake command on new-PXE server/client machines using new Hub/router.†

S: We manually turn those on and off. After that ether-wake (wake-on-Lan) command was successful.†

P: PEX (network boot) is now installing 2009.5.1†

S: finished. status PXE Server (Open)†

P: NIS (network information services) will be moved from tube to flex 2009.5.1†

S: not yet finished. status Network Information System†

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The following problems are solved.

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P: We move /etc/passwd then we can not be root. No more even shutdown.†

S: cntl-alt-del and reboot. Then when OS selection, push any arrow.†

Then many selection of OS appears. Select one of OS, and press E. Then select kernel and press E again. Then you can edit the command for starting kernel and add "single" in the last of the command. Finally select "b" for booting and single user mode appears. Make /etc/passwd files and exit and runlevel 5 is recovers.

Even if we used NIS, we should not delete /etc/passwd /etc/group and /etc/shadow.

P: Flex was in a trouble today (2009.06.01). Problem was, we were failed to log-in to the flex. NIS is not running. Finally we solved it. See solution†

S: We found the graphics card is very unstable on Tube machine (172.17.4.134). May be accidentally we pull the card out and tube machine was failed to boot properly. As Flex uses NIS from Tube that is why we were unable to log on to Flex.†

P: linux emacs ispell error (no language "eu") 2009.4.24†

S: solved. "M-x ispell-change-dictionary" and select english†

S: solved. Edit .emacs to add (setq ispell-dictionary "english")†

P: How to update the files of remote to the files of local†

S: solved. "rsync -avc -e ssh saito@remote:/home/saito/book09/ /rsaito/book09"†