What is Block Data?

[kisalipa]

Hi Friends,

I get the basic understanding of what a block data is, in the sense the blocks are the amount of data stored physically in a hard disk. Is my understanding correct? (I am referring to the context of SAN storage technology). How does it write the block into the disk? Whats the relation with file system and block?

[Cali]

Yes

"Block Storage" or "Block Data" means you create a Volume (LUN) on the Storage an present (export) it to one (or more) Server.

The Server sees the Volume a an local Volume format it in the Filesystem of the OS (NTFS, VMFS or whatever) and than wirte in Blocks (Cluster).

In "File Storage" the Storage present a Share (CIFS, NFS) to the Server(s) and the Server write the Data to the Share.
The Server did not know the Format of the Filesystem or where the Files reside.

[Dennis Handly]

Block storage can also have different RAID levels and be stored in multiple places (network raid) for resiliency.

It can also have snapshots.