amd64 - bootloader and BIOS see 16gb ram, kernel does not
After being away from OpenBSD for about 2 years, I recently decided to take another look at it for a server I am deploying. The machine is a 8-way amd64 (Intel quad Xeon x 2) with 16GB ram. The BIOS and bootloader correctly see all 16gb, but the kernel only sees 4.00GB (a very non-random amount, indicating to me an artificial limit is being imposed somewhere). Just for comparison purposes, amd64 Windows and amd64 Linux also both see 16gb, but these are not being considered for deployment. I've tried both 4.2 and -current from a week or so back, and have the same problem on both. I also went through the -GENERIC config and GENERIC-MP config and tried to see if any options in there were applicable, but did not see anything that seemed appropriate to fix this issue. A few notes: 1. I am using the amd64 platform release, not i386 (in case someone thought I was trying to do some PAE-related stuff). I verified that it really is the amd64 kernel and not a rogue i386 one that slipped in there accidentally (which would explain the 4GB limit without PAE). 2. Both GENERIC and -MP only see 4gb, but -MP _does_ correctly see all 8 cores. 3. I checked the archive and noticed that some people have had no issues with similar configurations, so I'm probably doing something wrong or I might be missing a config option. (Most of these success stories are using Sun hardware - the machine in question is not, but I'm not sure why the system would be picky in that respect). 4. The memory ranges reported by the bootloader are correct - typical mappings up to 4gb, followed by a large 12.8GB range starting at physical 5GB. All the ranges are enabled. 5. It's a Dell server, in case that matters to anyone. Any thoughts or specific reason why I _should not_ expect this configuration to work (with all 16gb usable) ? -ml [EMAIL PROTECTED]
Re: amd64 - bootloader and BIOS see 16gb ram, kernel does not
Mike Larkin wrote: After being away from OpenBSD for about 2 years, I recently decided to take another look at it for a server I am deploying. The machine is a 8-way amd64 (Intel quad Xeon x 2) with 16GB ram. The BIOS and bootloader correctly see all 16gb, but the kernel only sees 4.00GB (a very non-random amount, indicating to me an artificial limit is being imposed somewhere). Just for comparison purposes, amd64 Windows and amd64 Linux also both see 16gb, but these are not being considered for deployment. I've tried both 4.2 and -current from a week or so back, and have the same problem on both. I also went through the -GENERIC config and GENERIC-MP config and tried to see if any options in there were applicable, but did not see anything that seemed appropriate to fix this issue. A few notes: 1. I am using the amd64 platform release, not i386 (in case someone thought I was trying to do some PAE-related stuff). I verified that it really is the amd64 kernel and not a rogue i386 one that slipped in there accidentally (which would explain the 4GB limit without PAE). 2. Both GENERIC and -MP only see 4gb, but -MP _does_ correctly see all 8 cores. 3. I checked the archive and noticed that some people have had no issues with similar configurations, so I'm probably doing something wrong or I might be missing a config option. (Most of these success stories are using Sun hardware - the machine in question is not, but I'm not sure why the system would be picky in that respect). 4. The memory ranges reported by the bootloader are correct - typical mappings up to 4gb, followed by a large 12.8GB range starting at physical 5GB. All the ranges are enabled. 5. It's a Dell server, in case that matters to anyone. Any thoughts or specific reason why I _should not_ expect this configuration to work (with all 16gb usable) ? -ml [EMAIL PROTECTED] Hi, the following Undeadly comments might shed some light on your issue: http://www.undeadly.org/cgi?action=articlesid=20060123062745pid=5mode=expanded and http://undeadly.org/cgi?action=articlesid=20071007002942pid=6mode=expanded HTH Fred -- http://www.crowsons.com/puters/x41.htm
Re: amd64 - bootloader and BIOS see 16gb ram, kernel does not
Travers Buda wrote The developers need hardware to tackle this. It may be possible for me to loan out this hardware. Where is it needed, and for how long? An private reply is probably better here as to not spam the list. -ml
Re: amd64 - bootloader and BIOS see 16gb ram, kernel does not
Mike Larkin wrote: I see. Just for my personal reference, was this limitation documented somewhere (just want to make sure I didn't miss anything)...? If not, should it be? Finally, did this limitation always exist? I do recall several other posters mentioning that they had similar configurations that _did_ work, but this was about a year back. Perhaps one or two of them didn't realize that only 4gb were usable, but it seems unlikely that _none_ of them realized it. -ml Earlier in the thread there are some links to undeadly that do answer the questions above. Thanks for the info everyone. -ml
Re: amd64 - bootloader and BIOS see 16gb ram, kernel does not
Nick Holland wrote: The amd64 4G issue is a limitation of the platform...at the moment. It is being worked on, slowly, but there be dragons, and they all have to be slain. Nick. I see. Just for my personal reference, was this limitation documented somewhere (just want to make sure I didn't miss anything)...? If not, should it be? Finally, did this limitation always exist? I do recall several other posters mentioning that they had similar configurations that _did_ work, but this was about a year back. Perhaps one or two of them didn't realize that only 4gb were usable, but it seems unlikely that _none_ of them realized it. -ml
Re: amd64 - bootloader and BIOS see 16gb ram, kernel does not
* Douglas A. Tutty [EMAIL PROTECTED] [2008-02-11 20:47:47]: On Mon, Feb 11, 2008 at 02:04:20PM -0800, Mike Larkin wrote: 8-way amd64 (Intel quad Xeon x 2) with 16GB ram. The BIOS and bootloader correctly see all 16gb, but the kernel only sees 4.00GB (a very non-random amount, indicating to me an artificial limit is being imposed somewhere). Just for comparison purposes, amd64 Windows and amd64 Linux also both see 16gb, but these are not being considered for deployment. I've tried both 4.2 and -current from a week or so back, and have the same problem on both. I also went through the -GENERIC config and GENERIC-MP config and tried to see if any options in there were applicable, but did not see anything that seemed appropriate to fix this issue. I wonder if the fix for Compaq's with more than 16 MB of ram would be applicable? See the FAQ section 4.12.1. The fix involves a boot prompt command and if it works, a line in /etc/boot.conf Good luck. Doug. The developers need hardware to tackle this. -- Travers Buda
Re: amd64 - bootloader and BIOS see 16gb ram, kernel does not
Douglas A. Tutty wrote: On Mon, Feb 11, 2008 at 02:04:20PM -0800, Mike Larkin wrote: 8-way amd64 (Intel quad Xeon x 2) with 16GB ram. The BIOS and bootloader correctly see all 16gb, but the kernel only sees 4.00GB (a very non-random amount, indicating to me an artificial limit is being imposed somewhere). Just for comparison purposes, amd64 Windows and amd64 Linux also both see 16gb, but these are not being considered for deployment. I've tried both 4.2 and -current from a week or so back, and have the same problem on both. I also went through the -GENERIC config and GENERIC-MP config and tried to see if any options in there were applicable, but did not see anything that seemed appropriate to fix this issue. I wonder if the fix for Compaq's with more than 16 MB of ram would be applicable? See the FAQ section 4.12.1. no, the Compaq issue is a bug between the boot loader and the Compaq BIOS (probably enough blame to share between the two), on a platform that can handle the larger amounts of RAM. The amd64 4G issue is a limitation of the platform...at the moment. It is being worked on, slowly, but there be dragons, and they all have to be slain. Nick.
Re: amd64 - bootloader and BIOS see 16gb ram, kernel does not
On Mon, Feb 11, 2008 at 02:04:20PM -0800, Mike Larkin wrote: 8-way amd64 (Intel quad Xeon x 2) with 16GB ram. The BIOS and bootloader correctly see all 16gb, but the kernel only sees 4.00GB (a very non-random amount, indicating to me an artificial limit is being imposed somewhere). Just for comparison purposes, amd64 Windows and amd64 Linux also both see 16gb, but these are not being considered for deployment. I've tried both 4.2 and -current from a week or so back, and have the same problem on both. I also went through the -GENERIC config and GENERIC-MP config and tried to see if any options in there were applicable, but did not see anything that seemed appropriate to fix this issue. I wonder if the fix for Compaq's with more than 16 MB of ram would be applicable? See the FAQ section 4.12.1. The fix involves a boot prompt command and if it works, a line in /etc/boot.conf Good luck. Doug.
