Linode Block Storage Basics and Configuration

Linode Block Storage is a scalable and high-performance storage solution that can be attached to any Linode instance.

Linode Block Storage is a block-level storage solution, meaning data is stored in blocks rather than files. This allows for faster read and write speeds, making it ideal for applications that require high I/O performance.

Each Block Storage volume can be up to 10TB in size and can be attached to a single Linode instance.

Block Storage is a scalable, high-speed, and fault-tolerant storage service used to add additional storage to a Linode Compute Instance.

To create a new Block Storage Volume, follow the steps outlined by Linode Support techs.

First, you need to create a new Block Storage Volume.

This can be done by logging in to your Linode account and navigating to the Block Storage section.

Once you've created the Volume, you'll need to attach it to your Linode.

To do this, go to the Linodes section and select the Linode you want to attach the Volume to.

Next, you'll need to create a filesystem on the Volume.

This can be done using the mkfs command.

After creating the filesystem, you'll need to mount the Volume to make it accessible to your Linode.

Mounting a Block Storage Volume involves creating a mount point and using the mount command.

To manage your Linode Block Storage volumes, you can attach or detach them from your Linodes. To attach a volume, log in to the Cloud Manager, click on the Volumes link in the sidebar, locate the desired Volume, click the more options ellipsis dropdown menu, and select Attach. Then, complete the Attach Volume form that appears and click Save.

You can also detach a volume from a Linode by logging in to the Cloud Manager, clicking on the Linodes link in the sidebar, selecting the Linode that the Volume is currently attached to, and navigating to the Storage tab. From there, locate the Volume you wish to detach, click the more options ellipsis dropdown menu, and select Detach. A confirmation screen will appear, and you can click Detach to confirm.

If this caught your attention, see: Azure Storage Manager

To resize a Block Storage Volume, power off the Linode it's attached to, log in to the Cloud Manager, click on the Volumes link in the sidebar, locate the desired Volume, click the more options ellipsis dropdown menu, and select Resize. Enter the new Volume size and click Submit. Then, click Resize Volume to start the resize, and reboot your Linode after the Volume is resized.

If you're running a web application that expects to store all its data in a single data directory on a filesystem, you won't have the logic to store data across multiple disks. Most common web software, such as content management, forum management, and photo gallery software, just won't work with multiple disks.

To consolidate multiple block stores into a single mega disk, you can use the Logical Volume Manager, or LVM (version 2). LVM is a system software component that enables consolidation of multiple disks and shows them to the OS as a single disk with a single filesystem.

Related reading: What Is Azure Storage

You can use LVM to show a single disk with 7 TiB capacity if you have seven 1 TiB block stores. This means you can transparently add more block stores to the logical volume to expand its capacity without any client applications being aware of it.

LVM also offers up software RAID goodies, such as replicated storage, striping, and load distribution. If you plan to use a ZFS filesystem, then it comes with its own logical volume capabilities and should be treated as an alternative approach to using LVM.

Here are some benefits of using LVM:

Deleting a Volume can be a straightforward process if you follow the right steps. To start, you'll need to log in to the Cloud Manager.

First, you'll want to power off any Linodes that are currently attached to the volume you want to delete. This ensures that the volume isn't in use and can be safely deleted.

Next, locate the Volumes link in the sidebar of the Cloud Manager. This is where you'll find a list of all your available volumes.

To delete a volume, click the more options ellipsis dropdown menu next to the volume you want to delete and select Delete.

After selecting Delete, you'll be prompted to confirm the deletion. Click Delete once again to confirm.

Here are the steps to delete a volume in a concise format:

You can increase the size of a Block Storage Volume at any time after it's been created, up to a maximum of 10,000 GB.

To resize a Block Storage Volume, you'll need to log in to the Cloud Manager, power off the Linode it's attached to, and then click on the Volumes link in the sidebar. From there, you can select the Volume you want to resize and enter the new size.

Expanding a Block Storage Volume is a straightforward process, but shrinking it is a different story. Unfortunately, the Cloud Manager and Linode's APIs don't support shrinking a block store. This is likely due to concerns about inadvertently corrupting the file system.

If you need to shrink a block store, your best option is to copy all its data to a smaller block store and then destroy the original. This approach can be done using LVM's or ZFS's resize and mirroring/moving capabilities.

There are a few ways to achieve this, including using LVM or ZFS to mirror an existing block store to a new, smaller one, and then destroying the original. Another approach is to use lsyncd to mirror file changes in real time, or to use rsync to schedule a simple copying of filesystems.

Here are some of the methods you can use to shrink a block store:

It's worth noting that if you plan to use block stores for their expandability and will be running a public-facing service that can't afford downtime, it's a good idea to use LVM. LVM offers up software RAID goodies such as replicated storage, striping, and load distribution, and can transparently add more block stores to a logical volume to expand its capacity without any client applications being aware of it.

Block storage is a type of disk with expandable storage capacity that can be scaled per your current storage needs, also known as a "volume" in some places.

You can think of it as a disk that can be sliced up into multiple partitions, each with its own file system, and can be used as an additional disk with a Linode.

In contrast to fixed instance storage, which is limited by the plan's pricing, block storage allows you to exceed these fixed capacities without upgrading plans or buying more instances.

Block storage leads an independent existence with its own lifetime, so if you destroy a Linode, the block store and its data are not destroyed, but remain available for attaching to another Linode.

Here are some key facts to keep in mind:

Block storage is a type of disk with expandable storage capacity that can be scaled per your current storage needs.

It's essentially a disk that can be used as an additional storage device, allowing you to add more storage space to your server without upgrading plans or buying more instances.

Block storage is not a new concept in itself, but rather a marketing term that has become entrenched among cloud infrastructure providers to refer to variable capacity storage.

In fact, even the "disks" created from fixed instance storage are considered block devices by your OS.

Block storage is closely associated with storage area networks (SANs), which refer to saving data in raw storage volumes called blocks.

These storage blocks can each function as an individual hard drive and can be accessed using protocols like Fibre Channel, Fibre Channel over Ethernet (FCoE) or iSCSI.

Block storage is often used in workloads where network-based, low-latency storage operations are required, such as databases, critical applications, virtual machines, RAID implementations, and even file systems.

Block storage can also be used to boot an operating system, if so configured.

Here are some of the reasons why block storage may make sense in your IT environment:

Linode's Block Storage service allows for up to 8 TiB of storage capacity per server, which is a significant increase from the previous limit.

This is made possible by the fact that each server can have up to eight disks, and now each of these disks can be an expandable block store.

You can create 8 block stores and attach them to a single Linode, effectively giving you up to 8 TiB of storage per server.

This is a game-changer for users who need a lot of storage space, but don't want to pay for unnecessary RAM or CPU power.

For example, if you wanted to store all your photos and videos, you could start with a 50GB block store for $5 and a Linode 1GB instance for $5, and pay only $10 in the first month with an additional $5 every month.

Planning is key to making the most out of block storage. You should make use of instance storage for the swap and boot disks because they are likely to be faster.

For plans that come with a lot of instance storage, like the Linode 64GB and Linode 80GB, you can use their instance storage for data storage and add only a few block stores if needed.

A good approach is to allocate instance storage into boot, swap, and data disks, and wait until they're filled with data close to maximum capacity before adding block stores.

If you have a plan that includes 8 disk slots, you can add block stores as needed, expanding each one when it's getting close to its capacity.

You can partition each disk, including block store disks, to accommodate your specific needs.

To save money, it's best to allocate instance storage first, then add block stores one at a time, expanding them as needed.

Consider reading: What Is Google One Storage

When choosing a filesystem for your block store, you'll have to decide between Ext4, XFS, and ZFS. Debian, Ubuntu, and Arch default to Ext4, while CentOS 7 and above default to XFS.

XFS is reportedly better at handling large directories and large files, making it a good choice for distributed file systems like GlusterFS, Ceph, and HDFS. It's also the recommended disk file system for these systems.

However, XFS consumes more RAM and CPU than Ext4, limiting its use to Linodes with higher configurations. This is something to keep in mind when planning your setup.

It's also important to note that XFS can only be attached to Linodes with higher configurations due to its resource-intensive nature.

Another consideration is that XFS journal device should not be placed on an instance disk, or you risk severe data corruption in case of server loss. Always run your own benchmarks using tools like iozone and fio under realistic loads if performance is critical.

ZFS, on the other hand, is a relatively new filesystem in the Linux world but has a stellar reputation from its performance in the Solaris and BSD worlds. It's feature-rich and can also act as a logical volume manager.

Consider reading: Azure File Share vs Blob

Machine sharing can be a bit tricky, but there are some clever ways to access data from multiple machines.

A block store can't be attached to multiple Linodes at once, but you can still access its data from other machines.

You can use NFS (Network File System) to mount a block store on multiple machines over a network. Linode's kernels already have the necessary kernel modules.

DRBD (Distributed Replicated Block Device) is another option, but it's more of a hot backup mechanism than true sharing. It synchronizes operations across a network, making both servers see the same data.

NBD (Network Block Device) allows you to expose a block device to client machines as a block device, sending operations across the network to the server.

Here are some options for sharing a block store:

You can easily notify your end-users of outages using a customizable status page. Display cloud services or websites, as well as any custom monitors you add manually.

You can create multiple status pages tailored to different needs, and customize them to fit your specific requirements. This allows you to show Chicago on your status page and keep your end-users informed.

You can embed these status pages for maximum effectiveness, and display them wherever your users need to see them. This way, you can ensure that everyone is aware of any issues with your Block Storage in Chicago.

StatusGator makes it easy to create a status page that shows the status of your services, including Block Storage in Chicago.