I would like confirm one thing. Based on what I saw Redhat document before, look like CENTOS 5 (X86, 32 bits) only support 16 GB RAM.
Is this correct?
Thanks.
Eh? How can you have 16GBs on a 32bit kernel?
----- Original Message ----- | Eh? How can you have 16GBs on a 32bit kernel? | | -- | Regards, | James. | | http://www.jamesbensley.co.cc/ | | There are 10 kinds of people in the world; Those who understand | Vigesimal, and J others...? | _______________________________________________ | CentOS mailing list | CentOS@centos.org | http://lists.centos.org/mailman/listinfo/centos
PAE kernel supports 48-bit addresses available on modern Intel CPUs
-- James A. Peltier Systems Analyst (FASNet), VIVARIUM Technical Director Simon Fraser University - Burnaby Campus Phone : 778-782-6573 Fax : 778-782-3045 E-Mail : jpeltier@sfu.ca Website : http://www.fas.sfu.ca | http://vivarium.cs.sfu.ca http://blogs.sfu.ca/people/jpeltier MSN : subatomic_spam@hotmail.com
Quoting James Bensley jwbensley@gmail.com:
Eh? How can you have 16GBs on a 32bit kernel?
You can have up to 64GB using PAE https://secure.wikimedia.org/wikipedia/en/wiki/Physical_Address_Extension.
Barry
On Tue, Nov 16, 2010 at 04:14:01PM -0600, Barry Brimer wrote:
Quoting James Bensley jwbensley@gmail.com:
Eh? How can you have 16GBs on a 32bit kernel?
You can have up to 64GB using PAE https://secure.wikimedia.org/wikipedia/en/wiki/Physical_Address_Extension.
Yeah, but in reality you can't run 64GB 32bit PAE kernel. All the lowmem would be used for page structs, and the system wouldn't be usable.
16GB PAE 32bit system still has some lowmem available..
-- Pasi
On Wed, Nov 17, 2010 at 4:15 PM, Pasi Kärkkäinen pasik@iki.fi wrote:
On Tue, Nov 16, 2010 at 04:14:01PM -0600, Barry Brimer wrote:
Quoting James Bensley jwbensley@gmail.com:
Eh? How can you have 16GBs on a 32bit kernel?
You can have up to 64GB using PAE https://secure.wikimedia.org/wikipedia/en/wiki/Physical_Address_Extension.
Yeah, but in reality you can't run 64GB 32bit PAE kernel. All the lowmem would be used for page structs, and the system wouldn't be usable.
16GB PAE 32bit system still has some lowmem available..
I think CentOS 4 had a PAE kernel called hugemem that had a 2048/2048 address space that allowed for up to 64GB. That was done away with in 5 I believe in favor of going 64-bit if you have more then 16GB, even if you plan on using 32-bit apps.
-Ross
Well, not knowing much about it as I use 64 bit to address more then 4GB which is the mathematical max a 32 bit OS can address, perhaps they are using PAE to address 16GB?
But why would the poster be surprised at even 4GB max?
- aurf On Nov 16, 2010, at 2:09 PM, James Bensley wrote:
Eh? How can you have 16GBs on a 32bit kernel?
-- Regards, James.
http://www.jamesbensley.co.cc/
There are 10 kinds of people in the world; Those who understand Vigesimal, and J others...? _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
I think I did not say clearly. It is NOT application can use 4GB MAX. What I say is HARDWARE(server) HAVE 64gb ram OR 128 gb ram but O.S. only understand 16 GB.
--- 10/11/16 (二)，aurfalien@gmail.com aurfalien@gmail.com 寫道：
寄件者: aurfalien@gmail.com aurfalien@gmail.com 主旨: Re: [CentOS] CENTOS 5 (X86 32 bits) only support 16 Gb RAM??? 收件者: "CentOS mailing list" centos@centos.org 日期: 2010年11月16日,二,下午5:14 Well, not knowing much about it as I use 64 bit to address more then 4GB which is the mathematical max a 32 bit OS can address, perhaps they are using PAE to address 16GB?
But why would the poster be surprised at even 4GB max?
- aurf
On Nov 16, 2010, at 2:09 PM, James Bensley wrote:
Eh? How can you have 16GBs on a 32bit kernel?
-- Regards, James.
http://www.jamesbensley.co.cc/
There are 10 kinds of people in the world; Those who
understand
Vigesimal, and J others...? _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
I think I did not say clearly. It is NOT application can use 4GB MAX. What I say is HARDWARE(server) HAVE 64gb ram OR 128 gb ram but O.S. only understand 16 GB.
That was clear from the beggining.
With that amount of RAM you should really use a 64 bit OS. Otherwise, you will be doing a disservice to yourself...
Quoting mcclnx mcc mcclnx@yahoo.com.tw:
I would like confirm one thing. Based on what I saw Redhat document before, look like CENTOS 5 (X86, 32 bits) only support 16 GB RAM.
Is this correct?
Yes. I believe if you have more than 16 GB of RAM then it is recommended to use x86_64.
Barry
Don't forget your 32 bit apps which most certainly are stuck at 4GB regardless of PAE or not.
Actually, most 32 bit apps I've used address only up to 2GB.
Hence why you should really go for a 64 bit kernel.
- aurf On Nov 16, 2010, at 2:01 PM, mcclnx mcc wrote:
I would like confirm one thing. Based on what I saw Redhat document before, look like CENTOS 5 (X86, 32 bits) only support 16 GB RAM.
Is this correct?
Thanks.
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Doh! *facepalm*, PAE of course, read about it but not something I have ever used ;p
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Barry Brimer -
James A. Peltier -
James Bensley -
mcclnx mcc -
Miguel Medalha -
Pasi Kärkkäinen -
Ross Walker