Linux – Users and Groups – Part 1

Ok.. Lets start with creating a group called "dba" and create user "oracle" belongs to "dba" group. We could see that from "/etc/passwd" that oracle user id is 1521 and primary group id is 5000. But we haven't set the password yet for "oracle" user. If we watch closely "/etc/shadow" password the second column is !! which … Continue reading Linux – Users and Groups – Part 1


AWS Autoscaling – Min Desired Max

As mentioned here : MIN: This will be the minimum number of instances that can run in your auto scale group. If your scale down CloudWatch alarm is triggered, your auto scale group will never terminate instances below this number. DESIRED: If you trip a CloudWatch alarm for a scale up event, then it … Continue reading AWS Autoscaling – Min Desired Max

SFTP – Connections and File Permissions – Part 4

Continuing the SFTP series of blog pages - lets take a look at some random snippets which are really helpful. Specifying the private key while dong SFTP sftp -o "IdentityFile=/path/to/private_key" We can also place the options in "config" file. Sample contents of ~/.ssh/config Host the_hostname User user_name IdentityFile /path/to/private_key 2. Prepare a batch file with … Continue reading SFTP – Connections and File Permissions – Part 4

RedHat – Not reading root volume based on LVM

Environment Red Hat Enterprise Linux 4 Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 EXT and XFS file system Rescue Mode Issue How to repair filesystem in rescue mode for Red Hat Enterprise Linux System won't load after boot, requests fsck of root file system / (root) filesystem … Continue reading RedHat – Not reading root volume based on LVM

NFS “nobody” file permission issue

Files in mounted folder owned by nobody:nobody – I’ve tried to change using chown with the existing username and group which also present on the NFS server but still nobody:nobody. A: NFSv4 handles user identities differently than NFSv3. In v3, an nfs client would simply pass a UID number in chown (and other requests) and the … Continue reading NFS “nobody” file permission issue

AWS SSO with Azure Active Directory

Tutorial from Azure provided here : To configure the integration of Amazon Web Services (AWS) into Azure AD, you need to add Amazon Web Services (AWS) from the gallery to your list of managed SaaS apps. To add Amazon Web Services (AWS) from the gallery, perform the following steps: In the Azure Portal, on the left … Continue reading AWS SSO with Azure Active Directory

AWS – AutoScaling Health Check Timers

Autoscaling without health check of instances is not possible. After all it is how autoscaling maintains the minimum and maximum instances running in healthy state. It is also not possible to suspend the health check temporarily. Autoscaling health check type can be EC2 or ELB. If it is EC2 health check then it must be … Continue reading AWS – AutoScaling Health Check Timers