Topic: SME 7 or 8 in 64-bit

[tspoon1986]

Hi,

Excuse my ignorance, but after a bit of research I'm still confused as to whether or not SME can be run as a 64-bit operating system.

We're getting a new server next year that will have a 64-bit processor (Intel Xeon Quad Core 5500 Series), and although we have loved and used SME for years, I'd like to get the most out of the new processor.

As far as I can tell (and I'm happy to be corrected) a 32-bit operating system can be run on 64-bit hardware, but it can't take advantage of the extra memory capability and in some cases may operate more slowly due to the overhead of emulating a 32-bit processor.

Does SME 7 come in a 64-bit version? Will SME 8? It appears to me that CentOS 5 comes in a 64-bit version, although whether they mean a native 64-bit version or a 32-bit OS on 64-bit hardware I can't tell.

Can someone help me sort this out?

[janet]

tspoon1986

Does SME 7 come in a 64-bit version?

No

Will SME 8?

No

Do an Advanced Search on the forums for 64 bit for the brief discussions that took place. Not enough demand and certainly not enough developers.

[tspoon1986]

Thanks Mary. I did try to do a search but couldn't find much. It's a shame SME won't be in a 64-bit version, but I do understand the reasons.

[Stefano]

it's not a shame, it's unnecessary as CentOS/SME kernel (only smp) can handle an huge ram amount.
there are no real advantages to move SME to 64bit arch

my 2c
Stefano

[cactus]

it's not a shame, it's unnecessary as CentOS/SME kernel (only smp) can handle an huge ram amount.
there are no real advantages to move SME to 64bit arch

That is not completely true. There are other benefits although they are minor for server appliances IMHO as they have a wider bandwidth on for instance the I/O bus.

[vpurger]

... and perhaps KVM on SME8 (RH5.4) !

[cactus]

... and perhaps KVM on SME8 (RH5.4) !

I doubt that as Xen as a host OS is also not supported at the moment, the resources of the development team are very limited.

[CharlieBrady]

As far as I can tell (and I'm happy to be corrected) a 32-bit operating system can be run on 64-bit hardware, but it can't take advantage of the extra memory capability and in some cases may operate more slowly due to the overhead of emulating a 32-bit processor.

The 32bit OS in SME8 can use all the memory you can throw at it - but not in any one single program.

There is no emulation of a 32-bit processor, and no overhead in doing that.

There just aren't the capabilities of handling very large software objects (very large data sets and very large programs). There are also some inefficiencies inside the kernel if you have a very large amount of RAM, because it is not all directly addressable at any one time.

[Stefano]

That is not completely true. There are other benefits although they are minor for server appliances IMHO as they have a wider bandwidth on for instance the I/O bus.

ok.. but we are talking about SME, i.e. something that (teorically) should apply to medium enterprise.. if you really need to use all the "power" of the 64 bit architecture then, maybe, SME is not the right product for you

Stefano

[dhalliday]

I'm not sure sure the argument that 32bit is sufficient stands anymore. I run several SME servers and dearly wish they would support large memory (16GB in my case).  There are several reasons why this is important.

1) Large memory allows the OS to cache more files and can significantly increase file server performance. In this day and age even a few users can consume large amounts of data so even small offices will benefit from this.

2) I am running several websites in ibays, several of which have large databases, these would benefit greatly from a larger memory space.

3) tmpfs caching of read only files. This is a trick I use to dramatically speed up a critical website, I can mount a tmpfs filesystem to an I bay path then I copy all http files to a tmpfs at startup. This makes this critical site fly. A similar trick can be used with a web proxy cache to speed up browsing.

While I fully understand that there is simply no resources to implement a 64bit version I do find it a pity, at some point I would even posture that 32bit support should be dropped and only 64bit supported, 64bit Linux can run on most processors releases since 2004 and eventually we need to move on or get left behind.

Dave.

[Stefano]

hi

please read this page: Centos4 (and so SME) can handle up to 64 GB of ram (using hugemem kernel).. the only limit is that you can't have a single process using more than (approx) 4GB of ram..

if you need something more you should move to Centos 64bit.. but, I repeat, we are talking about SME, (i.e. Small Medium Enterprise)

do you really need SME 64 bit?

all IMVHO

Stefano

[dhalliday]

Stefano thanks for the reply and I am very glad to have hugemem supported. However it really does not help in many cases.  For example it would not allow me to create a 8GB tmpfs area or allow mysql to use a large memory model or even for the nfs to cache more than 4GB of inode info. That said, hugemem support is at least something and I am very glad to have it.

While I could move to Centos native or any number of other distributions I would hate to do so. I am a staunch SME supporter and will work around the limitations. SME really is one of the best, most secure and sensibly maintained distributions available, all the people here work hard on this and I have been using it many years since e-smith days.

My point is not that we should support native 64bit now, just that we should plan for it eventually (SME 9? 10?) The huge memory model may not be supported forever and it is not a fix for all limitations. I routinely have to set Java instances to 3GB and its only a matter of time until common middleware applications will be demanding >4GB. If we don't at least entertain native 64bit support at some point in the future we will be marginalized. How may 16bit paged memory systems do you still see around today?


Dave.

[byte]

My point is not that we should support native 64bit now, just that we should plan for it eventually (SME 9? 10?)

Check the forums for a thread on 64bit development, as you will see there was no where near enough donations/interest for a 64bit platform so I don't see one coming unless someone offers a substantial cost to develop a 64bit platform.  Who said there is going to be a SME 9 or 10? SME 8 isn't out yet and has been under development/beta testing for nearly 2 or so years.

[dhalliday]

If you are referring to this thread:

http://forums.contribs.org/index.php/topic,33017.0.html

The poll was closed over 3 years ago and many of the comments are also very old. Much can change in that amount of time. If it were still open I would offer cash and my time to help develop, document and test the thing.

As for v9 v10, I agree, in a community effort such as this it is very hard to predict what the future holds. Back when Mitel held control I seriously doubted we would ever see version 6 or a move of Redhat 9 but here we are looking at a beta for version 8.

The current all be it small group of developers and others really need to be commended for their great work to date.

Dave.

[kruhm]

Here's one small sample set of data for Centos downloads: http://iso.linuxquestions.org/centos/centos-5.3/

In short:

DISTRO                DOWNLOADS    PERCENT
TORRENT-X86       1,423                12.69%
TORRENT-X86_64  443                  3.95%
X86                      7,562                67.45%
X86_64                1,783                15.90%
                           11,211             100.00%

I suppose 64 will be developed when one of the following happens:
-a developer(s) gets a serious itch and can't take it anymore and develops it.
-a user(s) donates so much that convinces a developer(s) to put it on his or her task list.
-the demand from users gets so overwhelming that it can't be ignored anymore.

None of the above has happened yet. Please note that anyone can, in theory, fulfill the first two above requirements.