Block Level Storage & File Level Storage

Anyone who has used a Storage Area Network (SAN) has probably used block level storage before. Block level storage presents itself to servers using industry standard Fibre Channel and iSCSI connectivity mechanisms. In its most basic form, think of block level storage as a hard drive in a server except the hard drive happens to be installed in a remote chassis and is accessible using Fibre Channel or iSCSI.

 When it comes to flexibility and versatility, you can't beat block level storage. In a block level storage device, raw storage volumes are created, and then the server-based operating system connects to these volumes and uses them as individual hard drives. This makes block level storage usable for almost any kind of application, including file storage, database storage, virtual machine file system (VMFS) volumes, and more. You can place any kind of file system on block level storage. So, if you're running Windows, your volumes will be formatted with NTFS; VMware servers will use VMFS.
Remember, when you use a block-based volume, you're basically using a blank hard drive with which you can do anything.
From a use case standpoint, there are a lot of applications that make use of this block-level shared storage, including:

• Databases. This is especially true when you want to cluster databases, since clustered databases need shared storage.
• Exchange. Although Microsoft has made massive improvements to Exchange, the company still does not support file level or network-based (as in, CIFS or NFS) storage. Only block level storage is supported.
• VMware. Although VMware can use file level storage via Network File System (NFS), it's very common to deploy VMware servers that use shared VMFS volumes on block level storage.
• Server boot. With the right kind of storage device, servers can be configured to boot from block level storage.

 File level storage is usually accessible using common file level protocols such as SMB/CIFS (Windows) and NFS (Linux, VMware). In the block level world, you need to create a volume, deploy an OS, and then attach to the created volume; in the file level world, the storage device handles the files and folders on the device.

The two most popular storage system technologies are file level storage and block level storage. File level storage is seen and deployed in Network Attached Storage (NAS) systems. Block level storage is seen and deployed in Storage Area Network (SAN) storage. In the article below, we will explain the major differences between file level storage vs. block level storage. File Level Storage - This storage technology is most commonly used for storage systems, which is found in hard drives, NAS systems and so on. In this File Level storage, the storage disk is configured with a protocol such as NFS or SMB/CIFS and the files are stored and accessed from it in bulk.

• The File level storage is simple to use and implement.
• It stores files and folders and the visibility is the same to the clients accessing and to the system which stores it.
• This level storage is inexpensive to be maintained, when it is compared to its counterpart i.e. block level storage.
• Network attached storage systems usually depend on this file level storage.
• File level storage can handle access control, integrate integration with corporate directories; and so on.

Block Level Storage - In this block level storage, raw volumes of storage are created and each block can be controlled as an individual hard drive. These Blocks are controlled by server based operating systems and each block can be individually formatted with the required file system.

• Block level storage is usually deployed in SAN or storage area network environment.
• This level of storage offers boot-up of systems which are connected to them.
• Block level storage can be used to store files and can work as storage for special applications like databases, Virtual machine file systems and so on.
• Block level storage data transportation is much efficient and reliable.
• Block level storage supports individual formatting of file systems like NFS, NTFS or SMB (Windows) or VMFS (VMware) which are required by the applications.
• Each storage volume can be treated as an independent disk drive and it can be controlled by external server operating system.
• Block level storage uses iSCSI and FCoE protocols for data transfer as SCSI commands act as communication interface in between the initiator and the target.