Results 1 to 8 of 8

Thread: Question about how login stats are calculated on 12.04 LTS

  1. #1
    Join Date
    Dec 2008
    Location
    Taxes
    Beans
    415
    Distro
    Ubuntu Studio 12.04 Precise Pangolin

    Question about how login stats are calculated on 12.04 LTS

    If you install from the "minimal install" ISO you get a prompt near the end to enable automaigically applying security updates.
    I usually elect for that option -- one of the other things that happens when you take that option is that you get a cute little login script that provides some interesting statistics along how many pending updates are available and if a restart is required. I find this mildy amusing, and other than the extra time it causes at login, never thught too much about it until I noticed this:


    Code:
    Welcome to Ubuntu 12.04.2 LTS (GNU/Linux 3.2.0-38-generic x86_64)
    
     * Documentation:  https://help.ubuntu.com/
    
      System information as of Sat Mar  9 11:29:28 CST 2013
    
      System load:  0.0                Processes:            98
      Usage of /:   0.8% of 450.20GB   Users logged in:      0
      Memory usage: 1%                 IP address for bond0: xxx.xxx.xxx.xxx
      Swap usage:   0%
    
      => /mnt/md0 is using 88.0% of 9.40TB
    
      Graph this data and manage this system at https://landscape.canonical.com/
    
    0 packages can be updated.
    0 updates are security updates.
    
    Last login: Sat Mar  9 10:49:34 2013 from 
    
    :~$ df
    Filesystem       1K-blocks       Used Available Use% Mounted on
    /dev/sda3        472069424    3686732 444402868   1% /
    /dev/md0p1     10095015976 8879129108 703089336  93% /mnt/md0
    
    :~$ df -h
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/sda3       451G  3.6G  424G   1% /
    /dev/md0p1      9.5T  8.3T  671G  93% /mnt/md0


    After a certain utilization point on any given system the login descript displays a usage indicator regarding the level of utilization -- in this case the login script is squawking about 88% of /dev/md0p1 being used.
    runing 'df' or 'df -h' reveals utilization is actually a bit higher.

    Not really a big deal, but it isn an interesting quirk. is this just the difference in calculating MiB vs MB?

    Anyone have any experience with the set of packages that provide these login scripts? I know it's more than one package, as I tried to add it to a server without the option selected during installation.

  2. #2
    Join Date
    Apr 2008
    Location
    LOCATION=/dev/random
    Beans
    5,767
    Distro
    Ubuntu Development Release

    Re: Question about how login stats are calculated on 12.04 LTS

    Quote Originally Posted by MakOwner View Post
    If you install from the "minimal install" ISO you get a prompt near the end to enable automaigically applying security updates.
    I usually elect for that option -- one of the other things that happens when you take that option is that you get a cute little login script that provides some interesting statistics along how many pending updates are available and if a restart is required.
    I'm not actually answering your question but this script has nothing to do with whether you select automatic updates or not.

    I never choose to have automatic updates when I do a server installation but I still have this information displayed every time I log in.

    For more information on the MOTD (message of the day) script see here...
    https://help.ubuntu.com/10.04/serverguide/pam_motd.html

    If you want to know exactly where the information is coming from you should take a look at the scripts in the /etc/update-motd.d folder, you may find an answer to your question here.
    Last edited by Cheesemill; March 9th, 2013 at 07:38 PM.
    Cheesemill

  3. #3
    Join Date
    Feb 2013
    Beans
    Hidden!

    Re: Question about how login stats are calculated on 12.04 LTS

    Sorry, but
    Code:
    $ expr 8879129108 \* 100 / 10095015976
    87
    $ echo $((8879129108*100/10095015976))
    87
    $ echo 'scale=1;8879129108*100/10095015976'|bc
    87.9
    Don't forget that 5% of space on each ext2/3/4 filesystem are reserved for root user. To see how many bytes are reserved for root, try
    Code:
    sudo dumpe2fs -h /dev/md0p1 2>/dev/null|sed -nr 's/^(Reserved block count|Block size): *//p'|paste -sd\*|bc
    Last edited by schragge; March 11th, 2013 at 10:12 AM.

  4. #4
    Join Date
    Dec 2008
    Location
    Taxes
    Beans
    415
    Distro
    Ubuntu Studio 12.04 Precise Pangolin

    Re: Question about how login stats are calculated on 12.04 LTS

    Interesting - it may not be associated witth that selection, but selecting 'basic server' and 'openssh' along with that option is the only way I have ever seen it.
    I chased the scripts down once, but it was back when 10.04 was fairly new.

  5. #5
    Join Date
    Dec 2008
    Location
    Taxes
    Beans
    415
    Distro
    Ubuntu Studio 12.04 Precise Pangolin

    Re: Question about how login stats are calculated on 12.04 LTS

    Quote Originally Posted by schragge View Post
    Sorry, but
    Code:
    $ expr 8879129108 \* 100 / 10095015976
    87
    $ echo $((8879129108*100/10095015976))
    87
    $ echo 'scale=1;8879129108*100/10095015976'|bc
    87.9
    Don't forget that 5% of space on each ext2/3/4 filesystem are reserved for root user. To see, how many bytes are reserved for root, try
    Code:
    sudo dumpe2fs -h /dev/md0p1 2>/dev/null|sed -nr 's/^(Reserved block count|Block size): *//p'|paste -sd\*|bc

    And that was the other thing I was thinking about.
    Thanks for the method of calculating root reservation overhead!

  6. #6
    Join Date
    Feb 2013
    Beans
    Hidden!

    Re: Question about how login stats are calculated on 12.04 LTS

    Quote Originally Posted by MakOwner View Post
    Thanks for the method of calculating root reservation overhead!
    You're welcome. This even may be shortened as
    Code:
    sudo tune2fs -l /dev/md0p1|sed -nr 's/(R.*t|B.*e): *//p'|paste -sd\*|bc
    but the first form is more readable. If the filesystem is mounted, it may be simplified further by using mount point instead of device name:
    Code:
    stat -fc'(%f-%a)*%S' /mnt/md0|bc
    Last edited by schragge; April 22nd, 2013 at 01:06 PM.

  7. #7
    Join Date
    Apr 2008
    Location
    LOCATION=/dev/random
    Beans
    5,767
    Distro
    Ubuntu Development Release

    Re: Question about how login stats are calculated on 12.04 LTS

    I've tracked down the scripts that display the info, they live in /usr/lib/python2.7/dist-packages/landscape/sysinfo/.
    The relevant script for your question is disk.py.
    My python isn't too good but I'm sure someone else can figure it out, the script is as follows...
    Code:
    from __future__ import division
    
    import os
    
    from twisted.internet.defer import succeed
    
    from landscape.lib.disk import get_mount_info, get_filesystem_for_path
    
    
    # List of filesystem types authorized when generating disk use statistics.
    STABLE_FILESYSTEMS = set(
        ["ext", "ext2", "ext3", "ext4", "reiserfs", "ntfs", "msdos", "dos", "vfat",
         "xfs", "hpfs", "jfs", "ufs", "hfs", "hfsplus"])
    
    
    def format_megabytes(megabytes):
        if megabytes >= 1024*1024:
            return "%.2fTB" % (megabytes/(1024*1024))
        elif megabytes >= 1024:
            return "%.2fGB" % (megabytes/1024)
        else:
            return "%dMB" % (megabytes)
    
    
    def usage(info):
        total = info["total-space"]
        used = total - info["free-space"]
        return "%0.1f%% of %s" % ((used / total) * 100, format_megabytes(total))
    
    
    class Disk(object):
    
        def __init__(self, mounts_file="/proc/mounts", statvfs=os.statvfs):
            self._mounts_file = mounts_file
            self._statvfs = statvfs
    
        def register(self, sysinfo):
            self._sysinfo = sysinfo
    
        def run(self):
            main_info = get_filesystem_for_path("/home", self._mounts_file,
                                                self._statvfs, STABLE_FILESYSTEMS)
            if main_info is not None:
                total = main_info["total-space"]
                if total <= 0:
                    root_main_info = get_filesystem_for_path(
                        "/", self._mounts_file, self._statvfs, STABLE_FILESYSTEMS)
                    if root_main_info is not None:
                        total = root_main_info["total-space"]
                        main_info = root_main_info
                if total <= 0:
                    main_usage = "unknown"
                else:
                    main_usage = usage(main_info)
                self._sysinfo.add_header("Usage of " + main_info["mount-point"],
                                         main_usage)
            else:
                self._sysinfo.add_header("Usage of /home", "unknown")
    
            seen_mounts = set()
            seen_devices = set()
            infos = list(get_mount_info(self._mounts_file, self._statvfs,
                                        STABLE_FILESYSTEMS))
            infos.sort(key=lambda i: len(i["mount-point"]))
            for info in infos:
                total = info["total-space"]
                mount_seen = info["mount-point"] in seen_mounts
                device_seen = info["device"] in seen_devices
                seen_mounts.add(info["mount-point"])
                seen_devices.add(info["device"])
                if mount_seen or device_seen:
                    continue
    
                if total <= 0:
                    # Some "virtual" filesystems have 0 total space. ignore them.
                    continue
    
                used = ((total - info["free-space"]) / total) * 100
                if used >= 85:
                    self._sysinfo.add_note("%s is using %s"
                                           % (info["mount-point"], usage(info)))
            return succeed(None)
    Last edited by Cheesemill; March 9th, 2013 at 09:54 PM.
    Cheesemill

  8. #8
    Join Date
    Feb 2013
    Beans
    Hidden!

    Re: Question about how login stats are calculated on 12.04 LTS

    landscape.lib.disk comes with the package landscape-common. get_mount_info calls os.statvfs.
    Code:
    Python 2.7.3 (default, Jan  2 2013, 13:56:14)
    [GCC 4.7.2] on linux2
    Type "help", "copyright", "credits" or "license" for more information.
    >>> import os, statvfs
    >>> s=os.statvfs("/")
    >>> print s[statvfs.F_BSIZE], s[statvfs.F_BLOCKS], s[statvfs.F_BFREE]
    4096 2322270 501922
    >>>
    Last edited by schragge; March 9th, 2013 at 10:50 PM.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •