What is Blob storage ?

• When we upload our jar file, components, assets and meta data file to the Nexus repository, they all get stored in Blob store.
• In simple words, Blob store is Nexus storage to store all the uploaded files.

NOTE : If you don't know what Nexus is and how to setup you can check out my blog here

How does Blob storage works ?

• Blob store is internal mechanism to store all the binary parts of artifacts
• Blob store can be on a local system or a cloud storage
• Each Blob store can be used by multiple repositories or single repository or group of repositories

Blob store Interface

• The above image shows that a blob storage name "default" is present in the repository

• Check blob storage in your server

  ls /opt/sonatype-work/nexus3/
  

• You can check the blob storage directory

• Let's check inside blobs

  ls /opt/sonatype-work/nexus3/blobs
  

  

1. Name - The blob store's name as displayed in repository administration.
2. Type - The type of the blob store backend. The following options are available:
   • Azure Cloud Storage (PRO) - Stores blobs in Azure cloud storage.
   • File - Store blobs in file system-based storage.
   • Group (PRO) - Combines multiple blob stores into one.
   • S3 - Store blobs in AWS S3 cloud storage.
3. State - The state of the blob store.
   • Started indicates it is running as expected.
   • Failed indicates that there is a configuration issue and, as a consequence, the blob store failed to initialize.
4. Blob Count - The number of blobs currently stored in a blob store.
5. Total Size - The blob store's total size in bytes.
6. Available Space - A blob store's remaining storage capacity.

Create a new blob store

• Steps

  1. Click on create blob store
  2. Select the type of blob ( S3 or File )
  3. Provide name to the blob ( my-blob )
  4. Provide the path or leave it default ( the path should be access by nexus user ) the default path will be /opt/sonatype-work/nexus3/blobs/my-blob
  5. Click on save

• You can see a new blob store name my-blob get created

• Check in the blobs directory

  ls /opt/sonatype-work/nexus3/blobs
  

  

Things to keep in mind

1. The blob store can not be modified once they created
2. Blob store used by repository can't be deleted

Now , you can easily assign blob storage to any repository during creating one and once you assign a blob to a repository you can not change it. So, keep that in mind. Also, check out the Official Documentation of blob stores - Nexus Link to Official Documentation