Object storage vs file storage7/13/2023 ![]() Traditionally that would be using Fibre Channel optical cables or using Ethernet connectivity.ĭifferent protocols can be used here, mostly FCP or ISCSI, while more modern NVMe-based block storage appliances will use NVMe over Fabrics (NVMe-oF). That is, a LUN that is formatted with an ext4 filesystem can be used only by servers that are familiar with the ext4 filesystem, and even then, as mentioned above, no two servers will use this LUN concurrently.Īdditionally, servers would need to be connected to the block storage appliances in some way. An important distinction is that the block device is not aware of which of its used blocks include data and which include metadata therefore, accessing this data can be used only through a server that is familiar with the file system that is used on this block device. Therefore, these LUNs cannot be (easily) shared between different servers, and each server would see only its own assigned LUNs and no others.īecause a LUN is actually a group of blocks, the servers will usually (but not always) choose to create a file system on top of it, which means that some of the blocks in the LUN will be used for data and some for metadata (data about the data).Īn example of that would be saving a 128KB image under the user’s pictures directory, using 128KB for the image and an additional 4KB for data about the image file (i.e., creation time, access time, permissions, etc.), as well as 4KB for the directory structure. It also allows for better performance, as utilizing multiple devices concurrently provides higher performance than a single device, as well as additional sophisticated features (such as protection and more) that the storage appliance can implement.Ī block storage appliance can expose multiple “block devices” (LUNs) to a server, while the server would work with these LUNs as if they were local only to it (that is, as if they are its local HDD or SSD). This scenario allows servers to “see” and use block devices that are bigger than any single individual block device on the market. These are called LUNs (Logical Unit Numbers).įor example, let’s consider a storage appliance with 10 X 10TB HDDs that is exposing a 1 X 100TB block device (LUN) to a server or 100 X 1.0TB block devices (LUNs) to 100 different servers. Since individual block devices such as HDDs and SSDs have only specific sizes and performance levels, storage companies created storage appliances that are composed of multiple block devices that can then be “exposed” to servers as a different number of block devices. ![]() In this way any storage media (HDD, SDD, NVMe, other) can usually be exposed to the computer using it as a number of blocks (e.g., an 8TB HDD or SSD would be exposed as more than 2 billion blocks). A traditional block was 512 bytes on older storage systems, while the currently more accepted block size is 4K.įor example, if you have a picture that is 128KB in size, that picture will be saved on 32 blocks of 4KB each. What Is Block Storage?Īs we know, computer data is written in units called “bits”: 8 bits are called a “byte,” 1024 bytes are called a “kilobyte” (KB), increasing in size with megabytes (MB), gigabytes (GB), terabytes (TB), petabytes )PB), and so on.Ī “block” is actually several “bytes” of data grouped together. This blog takes a look at block storage and object storage, discusses the different technologies, and eventually discusses the relevant use cases of where each would apply. SAN (Storage Area Networks) appliances or All Flash NAS (Network Attached Storage) appliances, while IT and Storage admins would usually need to evaluate their internal workloads’ needs and use the most suitable storage appliance or even multiple different storage appliances for their different organization needs. Storage companies have designed and built storage solutions implementing these approaches and adding on top of them, e.g. To compound the complexity, different storage media types exist, each with its own performance, durability, and price, such as Hard Disk Drives (HDDs), Solid State Drives (SSDs and NVMes), and more. Moreover, each approach has evolved in parallel to the technologies that enable it (e.g., block devices with Fibre channel, network filesystems with NFS protocol, etc.). ![]() Each approach has its advantages, disadvantages, and requirements, along with the use cases to which they will apply. Some of the most common ways include using different types of file systems or block devices, using object stores, using different types of databases, and a host of other methods. There are multiple ways of storing data in computer systems. Block Storage Advantages and Disadvantages
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