OCI: How to resize Root Disk in OCI for Linux

 

In general, when you provision a Linux Compute the default size of boot disk will be 47 GB and sometimes this may not sufficient when the server usage keeps increasing. Even though while creating a Compute you have a flexibility of sizing the boot disk, we often miss to set or you may not be sure the initial sizing requirements.

This post will detail the steps on how to resize the root disk in Linux. Good news is that Oracle has provided a simple utility to resize root disk (/) in a simple and safer way.

As part resize first step is to resize Boot Volume in OCI.

Login to OCI, Open the navigation menu. Under Core Infrastructure, go to Compute and click Boot Volumes.

In the Boot Volumes list, click the boot volume you want to resize.

Then choose three dots and click Edit

Specify the new size in VOLUME SIZE (IN GB). You must specify a larger value than the boot volume’s current size (for e.g. 100GB)

Click Save Changes. This opens a dialog that lists the commands to rescan the disk that you need to run after the volume is provisioned.

You need to run these commands so that the operating system identifies the expanded volume size.

Now the resize of boot volume is completed successfully in OCI. We need to now proceed with steps to be performed Linux box.

Login to Linux VM as root user and run the OCI commands from above step.

# sudo dd iflag=direct if=/dev/oracleoci/oraclevda of=/dev/null count=1

# echo “1” | sudo tee /sys/class/block/`readlink /dev/oracleoci/oraclevda | cut -d’/’ -f 2`/device/rescan

Now the next step is to run the OCI utility oci-growfs command which will resize the / disk.

oci-growfs is available as part of oci-utils rpm for Oracle Linux 7& 8. If the compute is installed from OCI standard image this will be available by default. If the image custom, we need to install oci-utils rpm manually.

Extend the partition and grow the file system using the oci-growfs as below

# /usr/libexec/oci-growfs

Yoo! Boot disk resize is completed successfully.

Note: This action plan tested and works for Oracle Linux 7.

Useful LDAP Commands

 Below are the frequently used ldap commands that will be handful for DBA who is supporting OID.

OID Default LDAP port - 3060

AD Default LDAP port - 389

Query Attrributes for User from AD

ldapsearch -h <AD LDAP Server> -p <LDAP Port> -D "<LDAP User>" -w "<Password>" -W  "dc=domain,dc=com" "sAMAccountName=<Namee>"

Query Attrributes for User from OID

ldapsearch -h <OID LDAP Server> -p <LDAP Port> -D "<LDAP User>" -w "<Password>" -W  "dc=domain,dc=com" "uid=<Namee>"

LDAP Query to list groups assigned to User in OID

$ORACLE_HOME/bin/ldapsearch -h <OID/LDAP Server> -p <LDAP Port> -D "cn=orcladmin" -w "<password>" -b  "dc=domain,dc=com" -s sub "(uniquemember=cn=muthadi\, venkat,cn=users,dc=domain,dc=com)" dn

ADD GROUP TO USER FROM BACKEND in OID

Create LDIF file with attributes as below:

test.ldif

dn: cn=Administrator,cn=groups,dc=domain,dc=com

changetype: modify

add: uniquemember 

uniquemember : cn=muthadi\, venkat,cn=users,dc=domain,dc=com

Then Run below command

ldapmodify  -h <OID/LDAP Server> -p <LDAP Port> -D "cn=orcladmin" -w <password> -v -f test.ldif  

List All Groups in OID

./ldapsearch -x -h <OID/LDAP Server> -p <LDAP Port> -D cn=orcladmin -w <password> -L -b "cn=groups,dc=domain,dc=com" -s one "objectclass=*" dn

I use these regularly in my day to day activities, please feel free to correct or add any things that will be useful for others.