Ubuntu / Postfix problem - [newbie]

Discussion in 'Server Operation' started by barney.parker, Oct 14, 2007.

  1. barney.parker

    barney.parker New Member

    Hi,

    I have an ubuntu server, set up with postfix for virtual mail users as per the perfect setup -postfix / mysql etc....

    it has been working fine for several months, but a few days ago it gave up during an upgrade!

    At this point i would like to point out i am a complete linux newbie, so please give any answers like you're talking to a child please!!! :)

    OK, so i did an apt-get update, then an apt-get upgrade, but got an error with mysql not stopping and the initscript failing.

    I went to check out the log files, but all i got when i tried to nano mysql.log was a segmentation fault!

    i've googled around a bit and found that it could be A) a memory error, B) a disk error or C) a libraby corruption.

    my problem is i can't seem to find anythihng to help! Apparently with RPM you can verify packages, when you find the offendor, you can re-install it and things should go back to normal.

    unfortunately i can't seem to find the same for Ubuntu/debian....

    I know there's a memory test on the installer CD, but right now i don't have access to the machine, except through SSH...any thoughts there?

    I also can't seem to find a way fo performing a disk check...

    The machine is pretty old, but runs in an air conditioned server room. it could well be a memory problem....


    now to postfix: when i send a mail to the server all seems fine. I tried using telnet, and postfix told me the mail had been queued, but it never appeared in the virtual mailbox folder (/home/vmail/[domain]/[user]/cur (or any other folder in this tree)

    i can't view log files because of this segmentation fault, and i have no idea how to use any other text editor for the job, but i guess there might be some answers in there....


    does anyone have any ideas on what i can do here?

    I can get access to the machine in the next few days, but i'd like to have a few firm ideas on what i can try as i will be on site for only a few hours....


    thanks in advance, any help will be gratefully accepted!!!
     
  2. falko

    falko Super Moderator Howtoforge Staff

    Which tutorial did you use to set up the system?

    Do you get any error messages when you run
    Code:
    /etc/init.d/mysql restart
    ?
     
  3. barney.parker

    barney.parker New Member

    /etc/init.d/mysql restart

    gives...

    /etc/init.d/mysql: line 52: 26503 Segmentation fault grep -q ^expire.logs.days $CONF

    At this point i think i need to examine the basics. I am on site with the machine today so i am going to run the cd based memory test. If this is the fault it's no problem, the mchine is pretty old and i have a ton of spare memory hanging about.

    I still have no idea how to perform a disk check except restart many times (30 i think!)

    I also still need a way to verify all the packages. I am guessing this is part of the fault, since faulty memory of a faulty disk could easily result in a damaged package download (although i am not sure when apt does checksum checks...)

    I will post again after the memory test, but in the mean time, anyone got any other thoughts?

    Question: If i were to remove mysql-server-5.0, and then reinstall, will me previous database data still be present?

    Thanks in advance!
     
  4. falko

    falko Super Moderator Howtoforge Staff

    I *think* so, but to be sure, you should back up your databases: http://www.howtoforge.com/faq/6_3_en.html
     
  5. barney.parker

    barney.parker New Member

    OK, i ran the memory test. it's been running for nearly 24 hours and no errors, so i don't think the memory is at fault....

    it's my guess that it's not the disk either, although i still haven't found a way to do a disk check in linux....

    I am now suspecting that it's a package related issue....

    does anyone know of any method of asking apt-get to recheck all the packages installed for integrity?
     
  6. RossMcD

    RossMcD New Member

    Quoting barney.parker

    I am now suspecting that it's a package related issue....

    does anyone know of any method of asking apt-get to recheck all the packages installed for integrity?


    Barney, I get the same error. I ssh into my server from the desktop fine. I can apt-get update and upgrade. However, if I want to edit a file using nano or vi like sudo nano index.htm nano opens fine and I can see the file index.htm. If I then use the cursor keys to move through the file I get Segmentation Fault and get returned to the prompt. There is usually "OB" at the prompt. Funny thing is I can still see the remainder of the file nano opened and have to clear the terminal.

    Have you managed to solve the problem? Was it something to do with the software package?
     
  7. barney.parker

    barney.parker New Member

    RossMcD: Sadly, no!

    I search for ages trying to find a few details, I must admit this is the biggest downfall i have found with Linux (not that windows is any better, but XP has rollback and restore points, which can be really helpful...)

    In the end i got desperate to get the mail server back up, so i went for a complete reinstall.

    As i noted, the mem test went for a day without errors, so i was pretty sure that wasn't it.

    I also tried removing MySQL then re-applying it. Well what i found was that the database information stays, no problem there, but it didn't fix the issue either!!!

    So my guess at this point is that is could have been a package below mysql with the fault.

    When it came to reinstalling i found 7.10 Gusty Gibbon had just been released, so i gave it a try. I must admit I find it a little better. There little difference between 7.04 and 7.10, but 7.10 starts by allowing you to install the SSH server as part of the installation!

    If i new a little more about the way linux works would consider building a package verifier. It should be a simple matter of walking the depencency tree, and creating a checksum of each package which could then be placed into a database for later checking.

    If that was merged into apt you could keep that list way up to date on each update, then verifying would be simple.



    oh, and i never did find out how to do a disk check in ubuntu...



    It's funny, (NOT A WINDOWS Vs LINUX FLAME WAR) I heard alot about how linux was so damn great before i used it. While it does have potential, and Ubuntu certainly seems to have alot! it lacks a great deal of useful tools that as a windows IT guy for the last decade it's damned hard to get used to.

    In my opinion Linux should stop worrying whether it's better than windows, and just do the bloody job!

    My top list of niggles would be:

    1) make apps have names that have a meaning. now i know the package names have some meaning, but why on earth, when looking to edit a text file would i type vi, joe, nano or any of the others?

    in DOS i typed EDIT...worked for me....

    2) keep up with the latest trends (yes, that means copy microsoft if you have to). XP's driver rollback, and restore points can save hours of time and effort. ok, it's lazy, but when you have several hundred users to deal with, and a room stacked full of servers, shortening the support time means EVERYTHING!!!! it all comes down to money. Linux takes too long to administer!

    3) standardise...Windows has the Registry to keep app settings in. Linux has the /etc, or was that /var, or.... and do you call it postfix.cf, postfix.conf, postfix.cfg, main.cf.....who the hell knows, and who has time to bother with learning 1000's of names for files i shouldn't even have to know about! Seriously, yet another example of Linux being to slow! again, it works, and thats fine, but to become a commercial product, simplification means it's easier to learn. easy to learn means more trained staff available. more trained staff means lower wages, lower wages mean more staff in the IT dept, more staff means the job gets done quicker. It's a crap world, but it's the world we live in....work with it....

    4) give it a desktop, and work graphically. Now i know most Linux stuff can have a gui front end, but it's always some kind of bodged add-on. I don't want to use Apache and PHP to make everything work. I want a desktop that has the tools i want visually available. Again, the command line is perfect in some ways, but not when you stare at it 8 hours a day, 5 1/2 days a week, 52 weeks a year. I want to be able to view 6 apps at once, while configuring remote systems, giving users assistance, and troubleshoot network issues. ain't doing that from the command prompt!!!!


    Now i know someone will say "if you like windows so much, why are you using Linux?". well i don't particularly like windows. I don't like it's ability to create problems that shouldn't even exist. but what i do like about it is it ability to increase productivity. from the girl on reception, to my in IT, to the sales guys out in the field. Everything works seamlessly (or nearly).

    If i could add in the reliability and freedom of Linux, i'd be a happy man.....
     

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