Exadata cell node patching error_USB stayed back at old image

Exadata cell node patching error_USB stayed back at old image

 It seem USB stayed back at old image 20.1.9 though image was upgraded to 21.2.5; We can verify it in "imageinfo" command by taking login on problematic cell node.

#imageinfo

The Active image version and the Cell boot usb version should be same. if it different then the cell node patching takes time and it get fails with the error.

In this case, We need to rebuild USB using the below action plan which can be done online.

1. It may be required to stop the MS service to run this command.

#cellcli -e alter cell shutdown services MS

2. Recreate USB image with the following commands:

# cd /opt/oracle.SupportTools

# ./make_cellboot_usb -verbose -force

3. Remember to re-enable this once the make_cellboot_usb has completed.

#cellcli -e alter cell startup services MS

4. Once the execution is complete, validate configuration:

#cellcli -e alter cell validate configuration

5. Cross-verify the version

#imageinfo     ---> Active image version and the Cell boot usb version will be same.

6. Run cell node prechecks command and check if it still gives error.

Regards,

Kiran B Jaadhav

How to disable transparent_hugepage in linux

 How to disable transparent_hugepage

Here it shows that the transparent_hugepage value is enabled.

[root@testsrv~]# cat /sys/kernel/mm/transparent_hugepage/enabled

[always] madvise never

Steps:

1. Take backup of /etc/default/grub

#cp -rp /etc/default/grub /etc/default/grub_16May2022 

2. Edit the file /etc/default/grub by adding transparent_hugepage=never to the line 

GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=vg_os/lv_root rd.lvm.lv=vg_os/lv_swap rhgb quiet"

so the entry will be like 

GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=vg_os/lv_root rd.lvm.lv=vg_os/lv_swap rhgb quiet transparent_hugepage=never"

3. Take backup of file grub.cfg

#cp -pv   /boot/efi/EFI/redhat/grub.cfg  /boot/efi/EFI/redhat/grub.cfg-bkp

4. Create new grub configuration file

#grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg 

5. Reboot the server

#reboot

6. Verify whether the value is changed or not

#cat /sys/kernel/mm/transparent_hugepage/enabled

[root@testsrv~]# cat /sys/kernel/mm/transparent_hugepage/enabled

always madvise [never]

Regards,

Kiran B Jaadhav

Exadata Compute node patching prechecks error_Inactive lvm

Exadata Compute node patching prechecks:

Below commands will be used for Exadata compute node/DB node patching prechecks:

Note : Here we are applying QFSDP patch which is released on Jan2022

#cd /QFSDP/Jan_2022/33567288/Infrastructure/SoftwareMaintenanceTools/DBNodeUpdate/21.211221

#./dbnodeupdate.sh -u -l /QFSDP/Jan_2022/33567288/Infrastructure/21.2.8.0.0/ExadataDatabaseServer_OL7/p33665705_212000_Linux-x86-64.zip -v 

While doing patching prechecks on compute node if you get below error then 

Error :

  ERROR: Inactive lvm (/dev/mapper/VGExaDb-LVDbSys2) (15G) not equal to active lvm /dev/mapper/VGExaDb-LVDbSys1 (30G). Backups will fail. Re-create it with proper size

Ans:

1. The error clearly shows that there is size mismatch between LV /dev/mapper/VGExaDb-LVDbSys2 and /dev/mapper/VGExaDb-LVDbSys1

2. The inactive root LV is having 15GB size and the active root LV is having 30GB size.

   we can check it by using command

   #lvs

3. Make the inactive root LV same as size of active root LV

4. Command:

#lvextend -L +15G /dev/mapper/VGExaDb-LVDbSys2

5. Verify using command:

#lvs

Regards,

Kiran B Jaadhav

How to calculate Memory utilization on Linux server

 How to calculate Memory utilization on Linux Server:

[root@prddb1 root]# free -m

              total        used        free      shared  buff/cache   available

Mem:        6190278      981277     2684757       29303     2524243     5073648

Swap:         16383         596       15787

[root@prddb1 root]#

Here the values are in MB,

Total Memory = 6190278 

Free Memory or Available Memory = 5073648

So the memory utilization will be calculated using below way:

Memory Utilization = [(Total Memory - Available Memory )/Total Memory] *100

i.e

Memory utilization = [ 6190278 - 5073648)/6190278 ]*100 = 0.1804*100 = 18%

This means the current or real time total memory utilization is 18%

Regards,

Kiran B Jaadhav