In the world of network administration, a lot of focus is placed on monitoring and security tools, but comparatively, little attention is paid to network storage. This is surprising given that almost every enterprise needs a storage solution in one form or another. From storing websites and servers to emails and SAN devices, storage area networks are essential for maintaining an enterprise-scale network.
Larger networks running a variety of SAN devices must be constantly monitored in order to ensure long-term uptime. As a result, a number of SAN tools have risen to aid in capacity planning and prevent downtime. However, choosing a storage area network and SAN storage devices is often easier said than done. Not only do you have to take into account the needs of your current network, but your network will in the future as well. In this article, we talk you through how storage area networks work and break down some of the best SAN tools on the market.
What is a Storage Area Network?
Storage Area Networks (commonly referred to as SANs) are a scalable network and block-level storage method. A SAN takes storage resources off of your main network and transfers them into a unique high performance network. This network can then be accessed by a server as if it was a local disk rather than an entire network.
An enterprise might invest in a SAN solution for a number of reasons:
- Eliminates need for local disks
- Scalable – can be comprised of hundreds of unique disks
- High performance – doesn’t depend on network traffic
- Secure from unauthorized access and doesn’t need to be rebooted in order to add new disks
- Acts as a disaster recovery solution in the event of a network disaster
Guide to SAN Topology
One of the biggest things to understand about SAN is that there are a variety of different topology setups, each with their own inherent strengths. Your choice of topology structure is greatly influenced by your needs. In this section, we look at some of the core components of SAN topology, such as:
- Fibre Channel Arbitrated Loop
- Single and Dual-Switch
- Core-edge Topology
Fibre Channel Arbitrated Loop (FC-AL)
The most basic Fibre Channel used within SAN systems is the FC-AL. In an FC-AL, devices are connected together in a loop without a switch and each device connects to the next one in the chain. This is a popular model in SAN systems but it has the disadvantage of low performance and, potentially, complete failure. The failure of one device within the loop will break down the whole system. In this section we’re going to run through the basics of SAN topology to give you an idea of what setups companies are using.
Single and Dual-Switch
One way to mitigate the risks of a complete loop failure is to add in a single switch to the SAN topology. This allows multiple ports to speak at once and decreases latency throughout the system. It is important to note that not all switches are made the same. Two of the most common switch types are shown below:
- Director-class switch – Has thousands of ports, is high performance and scalable
- Basic switch – Has a limited number of ports and isn’t very scalable
In addition you can actually add multiple switches to the switched fabric. This is beneficial because it enables you to double the number of available ports and protects the system’s connectivity in case a switch goes down. The more ports you have available, the more flexibility you have in terms of usage.
If you add more than one additional switch, you start to form a mesh fabric. A mesh fabric is a series of interconnected switches. What separates a mesh fabric from a loop is that each switch is also connected via inter-switch links (ISLs).
Even though adding switches and using mesh fabric improves SAN performance, a number of limitations remain. The main problem is that adding switches can not get around the problem of a low port count. Larger organizations need plenty of ports, and a low port count is a major obstacle in this respect. As a result, core-edge topology has come to the forefront of SAN topology.
This model adds a larger fixed switch or director class switch attached to fix switches at the end of the topology. This gives larger organizations more ports at their disposal than a mesh fabric. However, this model is unsuitable for smaller organizations because it leaves an abundance of unused switches.
- SolarWinds Storage Resource Monitor (FREE TRIAL)
- Paessler PRTG SAN Monitor
- Nagios XI
- ManageEngine Applications Manager
- App Dynamics Storage Performance Monitor
- PowerAdmin Storage Monitor
- EG Innovations
- Broadcom SAN DIagnostics Capture
SolarWinds has developed a name for itself as one of the most prolific providers of network management solutions and Storage Resource Monitor is no exception. SolarWinds Storage Resource Monitor has been designed from the ground up as a tool to help provide full transparency over SANs. The program allows you to view storage objects throughout your network and point to signals of poor performance or storage failure.
For example, latency is highlighted in red if it’s lacking in performance. Alerts flag up when a LUN or RAID group suffers performance problems. Alerts are just the tip of the iceberg; you can generate reports such as Top 10 LUNS by latency or a capacity summary. These reports are invaluable to administrators looking to manage a large network infrastructure. You can also use the built-in SAN Management Performance Monitoring solution to forecast future usage and to conduct capacity planning.
Overall SolarWinds Storage Resource Monitor is a great package for enterprises that require clear oversight of their systems. While SME’s might not need this extensive range of features, the scalability of the platform means it will meet the needs of most organizations. SolarWinds Storage Resource Monitor is available for $2,995 (£2,304). A 30-day free trial is available here.
The PRTG SAN Monitor is one of the leading infrastructure monitoring tools. The PRTG data collection interfaces are called “sensors.” A sensor monitors one particular physical aspect of your infrastructure or focuses on one attribute of data processing and movement. You can tailor your implementation by choosing which sensors to turn on. The PRTG software includes four sensors that specifically track storage area networks. Paessler also includes sensors that track hardware from specific manufacturers and these will monitor your SAN as well.
The four universal SAN sensors cover:
- system health, looking at factors such as temperature and voltage
- the performance of disk drives
- statuses of logical and physical disk drives
- statuses of cases, controllers, and power supplies
Monitoring traffic is protected by the Secure Shell (SSH). This gives your administrative data extra privacy and so you can safely include remote sites in your centralized monitoring console.
The data collected by sensors is assembled into display formats in the dashboard. The display includes useful graphical representation, which makes status recognition easy. You can customize the dashboard and you also get the opportunity to customize reports that are generated through the system. The PRTG package ships with a number of pre-written reports as well.
PRTG covers a lot of other infrastructure factors and data collected on server and network health will add to your ability to keep your SAN available and active.
If you are interested in the PRTG package, Paessler gives you two implementation options. You can access the software online as a cloud-based service or you can install it on your premises. The software runs on the Windows environment. You can use the system for free perpetually to monitor up to 100 sensors. If you want a larger number of sensors, you will have to pay. However, you can get the SAN Monitor with PRTG on an unlimited number of sensors on a 30-day free trial.
3. Nagios XI
Nagios XI is one of the most well known network monitoring platforms in the world, but many administrators forget it also functions incredibly well as a SAN management tool. All you need to do to start SAN monitoring through Nagios is download additional plugins. Plugins such as Check SAN Switch Health (checks overall health of SAN switches) and Check HP MSA P2000 (which checks the status of components within the SAN) help create a complete SAN monitoring experience.
The sheer variety of plugins available allows you to extend the basic functionality of Nagios to act as a comprehensive SAN monitoring suite. Outside of its capability as a SAN, Nagios is also an adept networking monitoring platform. You can customize the layout of the GUI to help you to gain transparency over your network.
Nagio’s capacity planning features are incredibly useful when monitoring SANs. For example, you can create automated capacity planning graphs to help you identify how to scale your network storage. This feature makes it ideal for network administrators monitoring infrastructure for a large enterprise. Nagios is available for $1,995 (£1,476) and can be downloaded here.
4. ManageEngine Applications Manager
ManageEngine is another name that gets a lot of recognition within the administrator community. ManageEngine Applications Manager is a network monitoring solution that also functions as an effective SAN monitoring platform. The ManageEngine OpManager tool is a network monitoring system that will add connection performance details to the SAN monitoring capabilities of ManageEngine Applications Manager.
Applications Manager allows you to monitor both your SAN and network performance. Users can monitor switches, storage arrays, tape libraries, servers, and network devices all from one platform. In terms of visualization and performance monitoring, Applications Manager offers a very competitive product. Its graphs and root cause analysis provide information on memory capacity and other useful metrics.
You receive alerts when you’re network experiences poor performance or when your storage is almost full. Even though ManageEngine Application Manager isn’t tailor made for SAN monitoring, it can hold its own against the competition. In terms of pricing, ManageEngine Applications Manager offers a number of packages.
The professional edition can be purchased on an annual subscription starting at $945 (£702) for 25 monitors. Larger enterprises have a variety of options for 50 and 100 monitors before reaching the maximum of 250 monitors for $7,195 (£5,346). The full list of pricing options can be viewed here.
While the SevOne platform doesn’t have the most compelling GUI, it makes up for this in terms of its monitoring facilities. In SevOne you can manage your SAN storage from an overhead perspective and generate capacity reports to help detect when storage needs an upgrade. SevOne also has Custom Calculations, which add storage values from different devices together to provide you with a more accurate picture of how much space you have available.
SevOne’s monitoring abilities are extensive and visually intensive. You can receive a report on outages and uptime across all of your network devices. This helps to cut straight to the core question of whether storage is up and running or incurring problems. You can monitor server CPUs, memory, switch ports, and host bus adapters, which help drill down deeper into storage performance.
If you look beyond the dated GUI, this is an excellent SAN monitoring tool. In order to use SevOne for enterprise, either request a demo or contact the sales team for more information.
6. AppDynamics Storage Performance Monitoring
For mid-sized organizations, AppDynamics Storage Performance Monitoring is a competitive offering. Users can monitor their network storage right down to individual nodes, servers, and databases. In terms of network monitoring, AppDynamics offers a Unified Monitoring service. This is made up of a number of services such as Real User Monitoring, Database Monitoring, and Server Monitoring. This cross section helps build a complete view of your network and storage devices.
Even though AppDynamics can function as a SAN monitoring solution, it doesn’t have the depth that products like SolarWinds Storage Performance Monitor do. This is unfortunate as Storage Performance Monitoring carries a premium price tag of $3,300 to start. If you’re looking for a SAN solution, then you might want to pass in favor of a more specialist platform like SolarWinds Management Performance Monitoring. That being said, AppDynamics remains a good choice if you want to use it for broader storage resources. AppDynamics also offers a 15 day free trial that can be downloaded here.
7. PowerAdmin Storage Monitor
If you want a more specialist SAN monitoring solution, PowerAdmin Storage Monitor is definitely worth consideration. This solution was built completely with storage management in mind and acts as a platform to manage your network health 24/7. You can monitor your CPU usage, memory, and network devices from user one interface. If you want to monitor multiple sites, use distributed monitoring to view storage in a remote location.
Storage Monitor’s geographical flexibility makes it a solid alternative for companies looking to manage storage solutions across multiple sites. Another useful feature is predictive disk usage, which helps to anticipate when you need to upscale your IT infrastructure. For many users, this is the entire reason behind using SAN in the first place.
PowerAdmin doesn’t stop there. The platform doesn’t skimp on reporting features and allows the user to create customized reports. These are useful for breaking down current storage status and capacity planning for the future. The combination of these features helps make Storage Monitor one of the best platforms on this list.
PowerAdmin offers a range of different pricing options to its users. The cheapest is PA Storage Monitor License, which is $24 each for licenses 20 to 49. This storage scale increases and you can pay $4 each for 1000 to 1999. You can download a free trial for 30 days here.
8. EG Innovations
While other platforms make take a more indirect approach towards storage management, EG Innovations cuts straight to the point. On the dashboard you are shown a breakdown of your “Infrastructure Health” from launch. Green bars indicate components with a healthy status and red denotes unhealthy services. This cuts out any unnecessary distractions and tells you immediately if your storage is experiencing any issues.
Along the top of the user interface, health status is compiled into a larger bar showing the percentage of network components that are up and running.
The lean design of the user interface makes this platform a good choice for mid- to large-size enterprises. It shows everything you need to monitor storage without having to click through endless menus. In the event that you require more depth, you can make use of reports as well. Reports can be generated by function, component, service, zone, and segment. A variety of versions of EG Innovations are available but you’ll have to request a quote in order to find out more information. A free trial can be downloaded from here.
9. Broadcom SAN Health Diagnostics Capture
One of the lesser known specialist SAN monitoring platforms is Broadcom’s SAN Health. With SAN Health you can record inventory devices and data on the historical performance of your SANs. SAN Health’s biggest value lies in its ability to help you refine your SAN strategy. It provides the information needed to efficiently identify faults and performance issues. You can view diagrams of your SAN switches, ports, and fabrics for closer inspection.
This platform is a great SAN monitoring solution. As a specialist solution, it inevitably lacks some of the broader features offered by companies like ManageEngine, but the depth of its SAN features make it a compelling storage monitoring platform. The full program can be downloaded for free here.
Track SAN and NAS systems
NAS is “network-attached storage” and if you are just at the point of deciding on your new storage solution, you might get this configuration and “storage-attached networks” mixed up.
A storage-attached network is a high-performance link between a server and a storage device. That network can connect several servers to one storage devices or one server to several storage devices. It can also connect several servers to a series of specialized storage devices.
Network-attached storage features a file server, which sends data over the network to other devices, which may be endpoints or may be other servers. So, with a NAS, you are interfacing to a server front end to storage, and with SAN, you are monitoring the links between servers and storage devices.
Whichever of these storage topologies you opt for, all of the eight SAN monitoring tools listed in this guide will work well for you because they all also have NAS monitoring abilities.
SAN: Scalable Storage
As a storage solution, SAN systems are difficult to beat in an enterprise environment. Once a network reaches a certain size, it is important to consider the use of SAN tools to upscale storage in line with future needs. SAN monitoring solutions like SolarWinds Storage Resource Monitor bring transparency to the heart of your storage strategy. Without a SAN monitoring platform, it can be challenging to oversee every device.
Ultimately, the better you understand how your network works, the better you can modify storage to meet your needs. Most traditional storage devices take their toll on CPU and network performance, but a SAN is the exception. While you’re more likely to see larger organizations incorporate SAN systems, as prices decline and the needs of smaller organizations grow, we can expect to see these tools adopted across the market.
When implementing a SAN solution, it’s a good idea to consider appointing a specific storage administrator. This ensures you have someone to oversee your storage strategy and make sure your capacity planning is on point. This way you won’t run out of space when you’re desperately in need.