When was the operating system installed?

Question

I'm getting ready to reinstall my OS, but I'm wondering how long it's been cranking along.

Please list the OS and the best way to find out when it was born and for S&Gs how long yours has made it without being killed by you.

Answer 1

On Windows, run "systeminfo" at the command prompt. You're looking for "Original install date".

Answer 2

On Windows NT-derived operating systems, you can find the installation date at:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\InstallDate

The date is stored as a number of second elapsed since January 1, 1970.

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For Linux installs on ext2 or ext3, I suppose you could get the creation date of the filesystem using the tune2fs command:

tune2fs -l <filesystem block device> | grep "Filesystem created"

I'm really not sure of a good way on Linux operating systems, since every distribution could do their own thing.

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I have a Linux box running presently that does production work and was installed in February, 2004. Longest continuous uptime on that machine was a little over 2 years.

I have a Customer who is running a Windows NT Small Business Server 4.5 machine that was installed in late 1999. (They are also still using some of the Windows 98SE-based PCs that they bought at that time, as well.) They shut the machine down every day (don't ask-- they have a paranoia about fire and turn off most of the electricity in their building every night), so the uptime isn't radical. Surprisingly, it's still running on the same two (2) Western Digital "Enterprise" SCSI disks and HP DAT drive that it was purchased with.

Answer 3

On Mac OS X, the file

/var/log/OSInstall.custom

contains the original installation date, for example

Native install completed 2009-01-30 22:16:14 -0800.

So, this command shows the install date and time:

head /var/log/OSInstall.custom

Answer 4

For Solaris (since at least version 8), check the install date of the SUNWsolnm package. It's the package containing the /etc/release file and won't be updated/patched.

   # pkginfo -l SUNWsolnm
   PKGINST:  SUNWsolnm
      NAME:  Solaris Naming Enabler
  CATEGORY:  system
      ARCH:  sparc
   VERSION:  10,REV=2008.03.24.13.19
   BASEDIR:  /
    VENDOR:  Sun Microsystems, Inc.
      DESC:  Enable Solaris Name in /etc/release file
    PSTAMP:  re29796
  INSTDATE:  Jun 02 2008 17:01
   HOTLINE:  Please contact your local service provider
    STATUS:  completely installed
     FILES:        2 installed pathnames
                   1 shared pathnames
                   1 directories
                   1 blocks used (approx)

Answer 5

On a Unix you could look for the oldest /dev timestamp with,

 ls -lsrt /dev/* | head -1

Answer 6

On the Ubuntu system I am currently using, you can find what you want at /var/log/installer. IIRC, the Fedora/RedHat installer also leaves log files somewhere in the installed system (feel free to edit this answer to add their location).

Answer 7

Getting on over 8 years on a coupla Win2K boxes here too; there's one in particular I strongly suspect will outlive humanity and cockroaches. Since the advent of automatic updates continuous uptime is a thing of the past, but I've seen uptimes in the order of 600 days before.

Answer 8

All OS's - check your documentation/CMDB.

Linux - I'm not sure there is a standard or even reliable way that will work for all distros, unless the installer of your distros leaves logs.

E.g. on our servers we use kickstart and we log the output from the %post section to /root/

You can try stuff like the ctime of the /etc or /root inodes, but they may have changed (though they are less likely to be changed than other dirs)