@Rajasekar Ravichandran Welcome to Microsoft Q&A, thank you for posting your here!!
I have tested the below AZCLI command in my test Subscription to increase the OS disk size on Virtual Machine scale set and you can execute the below command in CLI from cloud shell in Azure Portal.
Commands:
az account set --subscription "provide your subscriptionID"
az vmss update -n vmssname -g resourcegroupname --set virtualMachineProfile.storageProfile.osDisk.diskSizeGb=150 # Replace -n with VMSS name and -g with resourcegroup name
Output:
"osDisk": {
"caching": "ReadWrite",
"createOption": "FromImage",
"deleteOption": null,
"diffDiskSettings": null,
"diskSizeGb": 150,
"image": null,
"managedDisk": {
"diskEncryptionSet": null,
"securityProfile": null,
"storageAccountType": "Premium_LRS"
"name": null,
"osType": "Linux",
"vhdContainers": null,
"writeAcceleratorEnabled": null
}
},
"userData": null
},
"zoneBalance": null,
"zones": null
}
Hope it helps!!!
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