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Hari Bantwal
Hari Bantwal

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OCI Instance with External Block Volume

There are moments when simple tasks can slow down our progress, often because they're not part of our regular routine. A recent experience brought this to my attention when I decided to delve into self-hosting for Windmill.dev and Supabase.

I realized that I needed external references to navigate the foundational aspects due to the multitude of available approaches. This post serves as a record of this experience, with the hope that the lessons learned can be valuable in future, more intricate endeavors.


Objective: Provision Instance in OCI, with external Block volumes to cater to Different Docker Services


Create compute instance through OCI Console
Create Instance

With below information:

Image: Oracle Linux 8
Shape: Ampere VM.Standard.A1.Flex
Cost: CHF 2.00/month
Subnet: Public
Add SSH Keys: Yes


Create Block Volumes through OCI Console
Create Block Volume

With below information:

Volume size: 50 GB Estimated Price: CHF 0.02301885/GB
Volume performance: Balanced 10 VPUs at CHF 0.00153459/PU/GB
IOPS: 25,000 IOPS (60 IOPS/GB)


Attach the Block Volume to the Instance
Navigate to Attached Instances on Block Volume Screen
Attach with below information

Attachment type: ISCSI
Access Type: Read/Write
Instance: Created in Step 1
Device path: /dev/oracleoci/oraclevdb


Run iSCSI commands & information

iSCSI commands to connect should be run using the commands shown "Attached Block Volumes"

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Remote SSH to the Instance to run the commands

ssh -i <Your SSH Private Key> opc@<PUBLIC_IP>
sudo iscsiadm -m node -o new -T ...
sudo iscsiadm -m node -o update -T ...
sudo iscsiadm -m node -T ...
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Create Disk Partition, Create File System Mount File System

sudo fdisk -l /dev/oracleoci/oraclevdb
sudo mkfs -t ext4 /dev/oracleoci/oraclevdb
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Mount file system

sudo mkdir /vol
sudo mount /dev/oracleoci/oraclevdb /vol
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OCI Block Volume is now mounted on Instance under the path /vol

Entry in /etc/fstab file for mounting after instance restart

/dev/oracleoci/oraclevdb /var/html-bv ext4 defaults,_netdv,nofail 0 2


How to Detach

  • Unmount the drive
sudo umount /vol
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  • Run the disconnect commands
sudo iscsiadm -m node -T iqn....
sudo iscsiadm -m node -o delete -T iqn....
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Find the commands below iSCSI commands & information

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  • Detach the instance

Blockvoulume is extended, How to make it available

After extending the Blockvolume, commands to run for repartition


ubuntu@instance-wordpress-template-755807:~$ sudo parted /dev/oracleoci/oraclevdb
GNU Parted 3.4
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) unit s                                                           
(parted) print
Model: ORACLE BlockVolume (scsi)
Disk /dev/sdb: 4294967296s
Sector size (logical/physical): 512B/4096B
Partition Table: msdos
Disk Flags: 

Number  Start  End          Size         Type     File system  Flags
 1      2048s  2147483647s  2147481600s  primary  ext4

(parted) rm 1                                                             
Warning: Partition /dev/sdb1 is being used. Are you sure you want to continue?
Yes/No? Yes                                                               
Error: Partition(s) 1 on /dev/sdb have been written, but we have been unable to inform the kernel of the change, probably
because it/they are in use.  As a result, the old partition(s) will remain in use.  You should reboot now before making further
changes.
Ignore/Cancel? Ignore                                                     
(parted) mkpart                                                           
Partition type?  primary/extended? primary
File system type?  [ext2]? ext4
Start? 2048                                                               
End? 100%                                                                 
(parted) quit                                                             
Information: You may need to update /etc/fstab.

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Resize the extended Block Volume

sudo resize2fs /dev/oracleoci/oraclevdb1
 df -h
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