Memory Size Of Dom0 Of ExaOVM Has Been Reduced from 32GB to 8GB shortly after upgrading Exadata Image to 18.1.16.0 (Doc ID 2549735.1)

Last updated on JANUARY 30, 2020

Applies to:

Symptoms

This is  X6-2 OVM Exadata environment.

Recently, my customer has upgraded the exadata image from 12.2.1.1.0.170126.2 to  18.1.16.0.0.190513.2.

By the way,  the memory size of Dom0  has been reduced from 32 GB to 8 GB shortly after upgrading the exadata image to 18.1.16.0.0.190513.2.

+ Current information

As you see below, the memory size of DOM0 is around 8 GB:

[root@#######dm01 ~]# cat /proc/meminfo | grep -i memtotal
MemTotal: 7736676 kB

[root@#######dm01 ~]# xm list
Name       ID Mem  VCPUs  State   Time(s)
Domain-0 0  8005         4    r-----  52913.6

You can see that  the value of   dom0_mem is  32G  from grup.conf  like below:

[root@#######dm01 ~]# cat /boot/grub/grub.conf
# Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.

default=0
timeout=5
hiddenmenu
#splashimage=(hd0,0)/grub/oracle.xpm.gz
color white/blue yellow/magenta
password --md5 $1$Hdnwr/$Q5VoiZeTJrmNQsJnH9oFy.

title Oracle VM server Unbreakable Enterprise Kernel (4.1.12-124.26.12.el6uek.x86_64)
root (hd0,0)
kernel /xen.gz dom0_mem=32G,max:32G dom0_max_vcpus=4 no-bootscrub loglvl=all guest_loglvl=all com1=115200,8n1 conring_size=1m console=com1 console_to_ring crashkernel=448M@128M xsave=1
module /vmlinuz-4.1.12-124.26.12.el6uek.x86_64 root=LABEL=DBSYSOVS max_loop=1024 bootarea=dbsys bootfrom=BOOT ro loglevel=7 panic=60 debug pci=noaer log_buf_len=1m nmi_watchdog=0 nomce transparent_hugepage=never rd_NO_PLYMOUTH audit=1 earlyprintk=xen console=hvc0 numa=on swiotlb=262144 SYSFONT=latarcyrheb-sun16 LANG=en_US.UTF-8 KEYTABLE=us
module /initramfs-4.1.12-124.26.12.el6uek.x86_64.img

title Oracle Linux Server Unbreakable Enterprise Kernel (4.1.12-61.28.1.el6uek))
root (hd0,0)
module /initramfs-4.1.12-61.28.1.el6uek.x86_64.img

title Exadata_DBM_0: LINUX_BOOT_0 DOM0
root (hd0,0)
kernel /xen.gz dom0_mem=32G,max:32G dom0_max_vcpus=4 no-bootscrub loglvl=all guest_loglvl=all com1=115200,8n1 conring_size=1m console=com1 console_to_ring crashkernel=448M@128M xsave=1
module /vmlinuz-4.1.12-61.28.1.el6uek.x86_64 root=LABEL=DBSYSOVS max_loop=1024 bootarea=dbsys bootfrom=BOOT ro loglevel=7 panic=60 debug pci=noaer log_buf_len=1m nmi_watchdog=0 nomce transparent_hugepage=never rd_NO_PLYMOUTH audit=1 earlyprintk=xen console=hvc0 numa=on swiotlb=262144
module /initramfs-4.1.12-61.28.1.el6uek.x86_64.img

Changes

Upgraded  the exadata image to 18.1.16.0.0.190513.2 from 12.2.1.1.0.170126.2

Cause