Discussion Forums > Technology
Longest time you let your OS/PC on for ...
rl9009:
Or get this board and a cheapo power supply:
http://www.intel.com/products/desktop/motherboards/D945GCLF2-D945GCLF2D/D945GCLF2-D945GCLF2D-overview.htm
PowerMac:
--- Quote from: bloody000 on May 27, 2009, 02:11:36 AM --- (click to show/hide)Which operating systems provide uptime information ?
Operating systems we can usually work out uptimes for are:
* BSD/OS
* FreeBSD [but not the default configuration in versions 3 to 4.3]
* HP-UX [recent versions]
* IRIX
* Linux on Intel x86 processor, kernel versions 2.1 to 2.5.24
* Linux on ARM, M68k, MIPS, PowerPC, S/390, SH and SPARC processors
* NetApp NetCache
* Solaris 2.6 and later
* Windows 2000
* Windows Server 2003
* Windows XP
Operating systems that do not provide uptime information include;
* AIX
* AS/400
* Compaq Tru64
* DG/UX
* Linux before kernel version 2.1
* Linux on Alpha and IA64 processors
* Linux on Intel x86 processor from kernel version 2.5.25 (see below)
* MacOS
* MacOSX
* NT3/Windows 95
* NT4/Windows 98
* NetBSD/OpenBSD
* NetWare
* OS/2
* OS/390
* SCO UNIX
* SunOS 4
* VM
Additionally HP-UX, Linux, NetApp NetCache, Solaris and recent releases of FreeBSD cycle back to zero after 497 days, exactly as if the machine had been rebooted at that precise point. Thus it is not possible to see a HP-UX, Linux or Solaris system with an uptime measurement above 497 days.
Why do some Operating Systems never show uptimes above 497 days ?
The method that Netcraft uses to determine the uptime of a server is bounded by an upper limit of 497 days for some Operating Systems (see above). It is therefore not possible to see uptimes for these systems that go beyond this upper limit. Although we could in theory attempt to compute the true uptime for OS's with this upper limit by monitoring for restarts at the expected time, we prefer not to do this as it can be inaccurate and error prone.
Why does my uptime go back to 0 after 198 days ?
The Linux TCP stack uses the low 32 bits from the system uptime timer, and this timer, in recent kernel releases, runs at 250Hz. This means that the timer value wraps around to 0 after roughly 198 days. Although we could in theory attempt to compute the true uptime for OS's with this upper limit by monitoring for restarts at the expected time, we prefer not to do this as it can be error prone.
Why do you not report uptimes for Linux 2.6 or FreeBSD 6 ?
We only report uptimes for systems where the operating system's timer runs at 100Hz or less. Because the TCP code only uses the low 32 bits of the timer, if the timer runs at say 1000Hz, the value wraps around every 49.7 days (whereas at 100Hz it wraps after 497 days). As there are large numbers of systems which have a higher uptime than this, it is not possible to report accurate uptimes for these systems.
The Linux kernel switched to a higher internal timer rate at kernel version 2.5.26. Linux 2.4 used a rate of 100Hz. Linux 2.6 used a timer at 1000Hz (some architectures were using 1000Hz before this), until the default was changed back to 250Hz in May 2006. (An explanation of the HZ setting in Linux.)
FreeBSD versions 4 and 5 used a 100Hz timer, but FreeBSD 6 has moved to a customisable timer with a default setting of 1000Hz.
So unfortunately this means that we cannot give reliable uptime figures for many Linux and FreeBSD servers.
--- End quote ---
Mac OS X does report uptime:
--- Code: ---
Last login: Tue May 12 22:51:51 on console
kyle-barkers-mac-mini-2:~ Kyle$ uptime
8:15 up 15 days, 9:24, 2 users, load averages: 0.39 0.89 0.96
kyle-barkers-mac-mini-2:~ Kyle$
--- End code ---
bloody000:
They can't go to your house and type on your computer. ::)
kyanwan:
Production Server: Redhat Enterprise - 228 days. Shutdown for preventative maintenance. Current: up 15 days, 4:49, 1 user, load average: 0.00, 0.00, 0.00
Windows - about 2 months.
Linux, Slack 10.x - current: 16:57:57 up 107 days, 1:15, 1 user, load average: 0.12, 0.03, 0.01 ( This system only shuts down on power outages. I don't have enough UPSs on hand to get this system on the "uber" program. )
c614h2:
I don't actually use that for anything, but it only draws 8 watts so I leave it on to make uptime records.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version