Topic: Hardware for SME

[tropicalview]

Hi There,

I'm looking also in to buy a server for a company that needs to be reorganized, and they will start using SME.
to my surprise there was a discussion in this posting about 8GB of memory.
but nobody reacted on that that there is a 4GB limit for 32bit systems.

is my statement about 4GB true or is this only a Micky(mouse)soft / windows issue?
what is the real maximum for the SME to address?

Kind regards,

[tropicalview]

It seems to that CentOS does support more than 4gb of memory in 32 bit systems:

http://www.centos.org/product.html

Can anybody please advice me the best max memory for SME? i would like to run 2 VMwares also on it.

Kind regards,

[Stefano]

with its standard kernel SME can handle 16 GB of ram
search in the wiki for more info

[paradigm]

You can use up to 16 GB of memory in sme (more if using the "hugemem" variant of the kernel) , but the real

Limit here is that each process can use only 3 Gb of memory - this i believe is the limit with 32 bit systems ,

Windows server 2003 works in the way - you can use more then 4 Gb in a 32 bit os but only 3.some thing Gb for

process , it's called PE .

In pure 64 bit system every process can have access to all most all the memory.

[janet]

tropicalview

Documented here
http://wiki.contribs.org/SME_Server:Documentation:FAQ#Memory_usage_and_limits

Also see
http://wiki.contribs.org/SME_Server:Documentation:Administration_Manual:Chapter4
and while correct it is of limited value when considered in the context of modern equipment, virtual servers and email systems with all features enabled.

Can anybody please advice me the best max memory for SME?

Such a generic question (ie what is best?) can only be answered generically.
There is no best amount of memory that will suit all situations, as system specification depends on anticipated usage and load volumes.

Typically you would want not less than 4GB RAM if intending to run VmWare for good performance. If your system is going to cater for lots of users who frequently run server based web applications eg webmail, egroupware etc then memory demands will be much higher. Also if your systems receives large volumes of email  and you have anti virus and spam scanning enabled, then these processes alone will place large demands on memory usage.

So on a busy system running VmWare it would not be out of place to run 8 or 16MB RAM, or even more if warranted.
A common way of assessing whether more RAM is required, is to check swap memory usage using top or htop.
If swap memory usage is half of installed or allocated RAM, then you should install more physical RAM (or allocate more in a virtual server).

Keep in mind that Linux will always try to use all available RAM, which is a good thing to keep your server running fast.

Keep in mind also that you can limit the instances of concurrent mail messages in various parts of the system and utilize RBL lists and executable content message rejection etc etc, all of which reduce the load greatly on available memory. Doing this may slow mail processing a little but will also allow you to run a server with less RAM, quite comfortably.

Ultimately and usually it just comes down to how much can one afford to install and/or the system is capable of handling. As memory and hardware generally speaking is not costly these days, you can manually install the hugemem kernel variant, select it at boot up and your system will recognize 64GB of RAM, assuming the motherboard can accept it.

yum install kernel-hugemem
signal-event post-upgrade
signal-event reboot

When you see the list of kernels displayed, select the hugemem kernel.

[axessit]

For my 2c I use an HP ML110 G5 (entry level) with RAID 1 - came with M$2k3 preloaded as it was cheaper to get the hardware this way. Had great delight in formatting the hard drives. No problems installing SME, recognises the on board NIC. Installed another SMC or Edimax NIC for less than $10 (both work fine). Had an issue with the M/B after a reboot after about 9 months, but after spending a whole morning going through Mumbia help desk (as the server was my gateway, had problems getting a laptop patched through to the adsl router to get emails from HP support) but once they agreed it was a M/B, got a parcel the next morning with a brand new M/B and all instructions on how to replace the CPU etc. Even came with a small syringe of heat paste for the CPU heatsink.

As it was a server, they are bound by a next business day replacement, and I don't live in a main centre.

I have installed both HP ML110 G4 and G5 servers as well as IBM entry towers in several of my customer's sites all with SME no problems. They gather dust like a vacuum cleaner, so get a regular visit with the air hose.

I recommend a name brand with a 3 year warranty. Most M/B manufacturers only give 12 months that I know of, and if you Build it they may not give you anything more and try and blame it on other peripherals (like RAM, NIC, PSU etc)

I also strongly recommend a UPS - nothing like reliable power and clean from brown outs etc. Got a reasonable Blazer 800 UPS that supports serial cable and worked straight out of the box with NUT. APC also works.

Also think 2G of RAM is heaps. Unlike M$, Linux is not as memory hungry.

[janet]

axessit

Also think 2G of RAM is heaps....

Typically for lower load systems with a smaller number of users that is OK, but if you have a busy server with heavy mail & web app usage and lots of users, then memory and processor demands can be considerably more.
The "correct" amount of RAM for any given situation really depends on the server in question and how it's being used.

[paradigm]

Also think 2G of RAM is heaps. Unlike M$, Linux is not as memory hungry.

axessit how many users are those 2 GB ram servers serving ?

[axessit]

Small Office - 10 - 15 users typically, only using email, file server, printing and faxing (has Hyla Fax on one of them). Not hosting any web apps, so I guess Mary's comments are to be considered. The server also runs dansguardian internet filtering (great for stopping flash movies from the likes of youtube etc yet still allowing whitelist sites to run flash tutorials).

[kellned]

Hi del,

my English is not so good, that I can describe all the the details. I had the same problem with an mini ITX-board.
My solution is: disable the onbord ethernet interface in BIOS and use a dual port Ethernet-PCI-Interface-Card. (I use an old Compaq-Interface-Card, Street-price ca. 40 EUR) It is running without problems.

regards
Dieter

[del]

Hi kellned,

The main reason I have not gone down that route is I wanted to use a 1u rackmount case and I need the PCI slot (with riser) for a Digium analogue trunk card, but thanks for the idea.

Del

Hi del,

my English is not so good, that I can describe all the the details. I had the same problem with an mini ITX-board.
My solution is: disable the onbord ethernet interface in BIOS and use a dual port Ethernet-PCI-Interface-Card. (I use an old Compaq-Interface-Card, Street-price ca. 40 EUR) It is running without problems.

regards
Dieter

[kellned]

Please contact Marcel Fraunhofer IFF in the German forum.  He told me from a special Atom 330 mainboard with an other chipset for Ethernet-Interface. and his English is much more better.
regards
Dieter