On 9/1/10 12:43 AM, Nataraj wrote:
> Les Mikesell wrote:
>> On 8/31/2010 11:04 AM, Stephen Harris wrote:
>>
>>>> Stack size was only a problem for the 32 bit OS and not 64 bit. If one
>>>> is dealing with a terabyte or more of data, I don't see them using a 32 bit
>>>> OS.
>>>>
>>> Huh;
>>>
>>> /dev/mapper/Raid5-Media
>>> 3.3T 3.1T 216G 94% /Media
>>>
>>> % uname -sr
>>> Linux 2.6.18-194.3.1.el5PAE
>>>
>>>
>>>> I really don't see any really good reasons for using anything but 64 bit
>>>> any more, if the hardware supports it.
>>>>
>>> I don't find the RedHat 32bit/64bit split to be as clean as it should be
>>> (definitely messy when compared to Solaris). When it comes to needing to
>>> install 32bit and 64bit versions of the same program (eg perl 'cos you
>>> only have 32bit binary libraries from vendors) it gets a little hairy.
>>> And then Oracle really starts to get antsy on you.
>>>
>>> As a result, when I first installed CentOS 5 I stuck with 32bit because
>>> it was more stable. After all, my memory footprint is only around
>>> 200Mb on this machine; the rest is cache!
>>>
>>
>> The kernel and user apps are pretty much different things. You can run
>> a 64-bit kernel and 32-bit apps if you want. But the issue with a
>> 32-bit kernel besides what it can provide as a process address space is
>> that at least the way RH and CentOS build it, it uses 4k stacks which
>> may not be enough for some xfs operations.
>>
>>
> Are you saying here that I can take a system that has been installed
> from a 32 bit distribution and simply replace the kernel with a 64 bit
> kernel?
I'm not sure how much 64-bit support the kernel expects so there might be some
complications going that direction, but you can certainly install a 64-bit
system and run the 32-bit versions of the apps and have both versions of most
libraries available.
--
Les Mikesell
lesmikesell at gmail.com