Re: [Xen-users] xen on amd64 or intel

[Seneca <acenes@xxxxxxx>]

I first had also a mixed 64/32 bit setup with Xen 3.0.1: AMD64, 4GB
RAM, 2x250GB SATA Drives with a mix of software raid 1 and raid 0 (for
tmp and swap). The domU partitions were on LVM's, OS was debian sarge
amd64 + i386.

Most 32 and 64 bit domU's were working fine, but there was one problem
I could not get fixed (and why I finally changed everything to plain
32 bit using Xen 3.0.2 and debian etch-b2):

I could never connect to a DB2 instance running in a 32 bit domU
because it complained about not enough shared memory. I tried every
suggestion I could find, but finally found that the output if "ipcs
-l" did lack shared memory completely in 32 bit domU's whatever shared
memory setting I tried. So when the output is normally something as:

------ Shared Memory Limits --------
max number of segments = 4096
max seg size (kbytes) = 32768
max total shared memory (pages) = 2097152
min seg size (bytes) = 1

------ Semaphore Limits --------
max number of arrays = 128
max semaphores per array = 250
max semaphores system wide = 32000
max ops per semop call = 32
semaphore max value = 32767

------ Messages: Limits --------
max queues system wide = 16
max size of message (bytes) = 8192
default max size of queue (bytes) = 16384


In a 32 bit domU under 64 bit xen/dom0 it showed up as:


------ Shared Memory Limits --------

------ Semaphore Limits --------
max number of arrays = 128
max semaphores per array = 250
max semaphores system wide = 32000
max ops per semop call = 32
semaphore max value = 32767

------ Messages: Limits --------
max queues system wide = 16
max size of message (bytes) = 8192
default max size of queue (bytes) = 16384


Interestingly Oracle which also run in a 32 bit domU was not affected.
What does ipcs -l show in your 32 bit domU's?

Seneca



You wrote at Mittwoch, 12. April 2006 07:02:

HW> Am Mittwoch 12 April 2006 03:26 schrieb Edward Muller:
>> We have a quad core opteron system with 8GB of RAM, running Gentoo
>> (compiled for 64 bit kernel and userspace) and we run a mix of 32 bit and
>> 64 bit dom-U's.

HW> Something similar here: AMD64 with 4GB RAM running a 64-bit Gentoo Dom0, 
HW> running 30 DomUs, which are mixed 32-bit Debian/SuSE/FC4/CentOS and 64-bit 
HW> Gentoo, but all with a 64-bit kernel for the DomU. If you don't choose 
stupid 
HW> compiler-settings (beware of -Os, it creates broken code), it's running 
very, 
HW> very smoothly.

HW> --- Heiko.

HW> _______________________________________________
HW> Xen-users mailing list
HW> Xen-users@xxxxxxxxxxxxxxxxxxx
HW> http://lists.xensource.com/xen-users


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