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27

"uname -m" is the command you're looking for. You can run both 32bit and 64bit on modern intel and AMD processors, so "uname -p" is not going to help you (in addition it mostly doesn't work these days, this here core2 thinks the response to "uname -p" is "unknown"). Looking for existence of /usr/lib64 (as has been suggested) is not going to help you either, ...


25

Oh my... If you have 60Gb of RAM, please save yourself the hassle and use a 64-bit os. Also, 60 SQL instances sounds like a very odd way of doing things and I can't in good conscience suggest it. The amount of money a server of that stature costs, surely a proper SQL license would be in the budget? Windows is also incredibly intelligent when it comes to ...


15

uname -a and look for x86_64. If you want to know if your CPU can handle 64bit, cat /proc/cpuinfo and look for lm within the flags.


12

Yes, there is a distinction between 64bit and 32bit regedit. There are both 32bit and 64bit keys in the registry. The default 64bit registry editor will show both of these, the 32bit one only the 32bit keys. You can only edit 64bit registry keys using the 64bit version. You can edit 32bit registry keys in either version You cannot have both versions open ...


11

On a desktop machine, there are likely no problems. The kernel paged pool is smaller on a W2K3 / WXP machine w/ the /3GB switch set. This is probably not an issue for a desktop machine because you shouldn't be coming close to exhausting your kernel paged pool. On a server, exhausting the kernel paged pool will cause you problems, and it's much more likely ...


11

You need to enable the bigmem kernel. dpkg --get-selections | grep bigmem apt-get install linux-image-2.6-xxx-bigmem You can also check to see if it worked with: sudo grep -i memory /var/log/dmesg [ 0.004000] Memory: 899224k/917504k available (1693k kernel code, 17724k reserved, 746k data, 320k init, 0k highmem) highmem should be larger than 0k


11

On x64 platform, in Windows Task Manager, 32-bit applications will have "*32" appended to their names. So: firefox.exe *32 devenv.exe *32 svchost.exe means that both Firefox and Visual Studio are 32-bit applications, whereas Windows Services Host is a 64-bit app. On x86 platform, it's easy: 64-bit applications won't start. To reply to your last ...


10

VirtualBox can run 64-bit guests on a 32-bit host. You'll need to make sure your processor has hardware virtualization and that it is enabled in the BIOS. You can find some extra information at the VirtualBox Forums


8

Per process memory on 32-bit systems is 4GB (which is divided into 3GB for the process and 1GB for the kernel, by default). If you want your database to be able to access more memory /per process/ you have little choice but to install a 64-bit operating system. If the limit of 3GB per process is not bothering you, you might as well stay with the current ...


8

Well for a start HyperV is a server 2008 role, and so will not run on XP at all. The bare metal version still becomes the core OS, and isn't hosted by a guest OS. VMWare workstation will host 64bit guests on a 32bit OS though.


8

Gpo will automatically target the right system for you. A 64bit msi will not be installed on 32bit clients, but 32bit can be deployed on both 64 and 32. To avoid that 32bit msi's gets deployed to 32bit systems: Add the 32bit msi to the gpo. right click and then select properties. click the Advanced button untick Make this 32-bit X86 application available ...


8

If you want to see the "bitnes" of the OS installed you can run this command. $ uname -m Regarding the actual capabilities of the processor you can always look the model up inside /proc. $ cat /proc/cpuinfo


8

I am not aware of any issues with the 64 bit version. It's a 64 bit CPU, so I would definitely run 64 bit. I have been on hundreds of servers with 64 bit CentOS and never experienced any strange issues related to the fact, that it is a 64 bit OS. Also, you cannot allocate more than 4 GB of RAM with 32 bit. So to sum it up; go 64 bit.


8

You installed a 32-bit operating system on a machine with 16GB of RAM. This isn't going to work. Even if a 32-bit OS can technically use more than 4GB of RAM, no single process on the operating system can exceed that boundary. Start over and install a 64-bit operating system, and this problem will go away (along with all the other problems you're going to ...


7

This is trickier than I thought before I was in the market for a box that can handle 64-bit guests. Myth #1: All 64-bit hosts can run 64-bit guests. False. 64-bit guest requires specific hardware support: VT-x or AMD-V. Myth #2: All 64-bit processors support 64-bit guests. False. See myth #1. Myth #3: All current Intel 64-bit processors have VT-x. False. ...


7

cat /proc/cpuinfo look for the 'lm' flag, it means 'long-mode' i.e. 64-bit capable.


7

Exchange 2007's 32-bit implementation is there just for dev/test environments. What this means is that when you call in for support on a 32-bit edition, you'll get told 'no'. The 32-bit environments are at feature parity with the 64-bit version, but the long-term supportability of the 32-bit version is nonexistent. The 32-bit environments are there ...


6

Most modern 32-bit CPUs support PAE which allows them to address more than 4GB of physical memory, although a single process can only see 4GB at a time. The kernel will take some of this address space. This Stackoverflow post discusses how PAE works. Many operating systems (including Linux and MS Windows) offer an API that allows you to manipulate the ...


6

for RedHat/CentOS: $ uname -a Linux cs-centos 2.6.18-92.1.22.el5 #1 SMP Tue Dec 16 12:03:43 EST 2008 i686 athlon i386 GNU/Linux 32-bit i686 and/or i386 64-bit would have x86_64 in uname -a output


6

Current consensus seems to be that you are worrying needlessly. 64-bit is fine, and do not take up much more space than 32-bit to be of any significance. On a couple of my systems here: What 64-bit Size 32-bit Size /bin/ls 101K 91K /lib/libc.so 1.4M 1.3M /usr/bin/php5 5.5M 5.1M See – not that significant. Also, 64-bit ...


5

Just to confuse things, you can run a 64bit kernel with a 32bit userland, which is what I'm doing. In this case, uname -m returns x86_64 but I don't have any 64bit libraries installed so most 64bit programs won't run. So once you check uname, you need to look for /lib64/ld-linux-x86-64.so.2, /lib64/libc-2.7.so and /lib/ld-linux.so.2, /lib/libc-2.7.so to see ...


5

Before making any changes, you should first check if the processes you want to run are linked with the LARGEADDRESSAWARE flag. With the flag, there will be no changes to how the process uses memory. You can use the SDK Tools for this: dumpbin /headers exeName The headers spit out should include: Application can handle large (>2GB) addresses I ...


5

You will have less memory available to your kernel - the switch adjusts the kernel mode address space/user mode address space split, previously 2GB to 2GB, to 1GB to 3GB. Read Raymond Chen's post on /3GB, and the follow-ups, before proceeding.


5

/PAE doesn't change the user and kernel virtual address space assignments that were changed by using /3GB, but, you should not use /3GB and /PAE at the same time. Per Microsoft: When the physical RAM in the system exceeds 16 GB and the /3GB switch is used, the operating system will ignore the additional RAM until the /3GB switch is removed. This is ...


4

Plenty of drawbacks. By default, Windows will allocate a 4GB memory pool to every process, which is split 50/50 between the kernel mode processes (common to all apps) and user mode processes (unique for each app) (simplified explanation). An app running on the system therefore has 2GB of memory to play with, while the system itself has it's own 2GB. ...


4

First off, it sounds like you're leaning towards premature optimization with your question here. Machines are pretty fast. You need very significant load on any reasonably designed, normal-ish website (in the many hits per second range) before you're going to hit the limits of your dual Opteron system. (1) No, or at least not noticeably so. It may free up ...


4

I finally found the issue. There is an optional web.config configuration section for the ASP.NET cache: http://msdn.microsoft.com/en-us/library/ms164606.aspx The default configuration is absolutely nonsense for 32-bit boxes with more than 2 GB of RAM: it would start to throw out items of the cache, if less than 10% of physical RAM is available. Having e. g. ...


4

None. There is NO (!) sense today to install a 32 bit server. 32 bit will lock you into a total reinstall if you need more memory etc. - applications are another thing (makes quite often sense to run them 32 bit), but the OS should never be 32 bit.


3

I'm nearly in the same scenario as you (http://serverfault.com/questions/25758/is-there-any-reason-to-use-64bit-mysql-and-os-on-small-databases), and from what I could find out: MySQL on 32bit can not use more than 2GB RAM per instance no matter what you do with your kernel. If you're not running MySQL the situation might be different.


3

I think it would be better to ask the question, "Why would I stay with a 32-bit kernel?" I went all 64-bit on every piece of hardware that supports it as soon as I could and I have no regrets. At work we are running PostgreSQL servers on 64-bit CentOS 5 with 32 GB RAM and it is pretty great (Except for certain limitations with PostgreSQL itself, but ...



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