Since you mention server most likely there is hardware raid present. A combination of drives makes a group of disks to form a raid array or a set of raid which can be a minimum of 2 disks connected to a raid controller and making a logical volume or more, it can be a combination of more drives in a group. Hardware raid will cost more, but it will also be free of software raids. Mar 26, 2020 in this tutorial, well be talking about raid, specifically we will set up software raid 1 on a running linux distribution. Comparing hardware raid vs software raid setups deals with how the storage drives in a raid array connect to the motherboard in a server or pc, and the management of those drives. Someone told me that linuxs software raid was less reliable than hardware raid. Software raid is part of os, so no need to spend extract money. How to set up a software raid on linux addictivetips.
Raid stands for redundant array of inexpensive disks. The linux kernel contains an md driver that allows the raid solution to be completely hardware independent. But a couple years ago 2003 when i was building my newest server which conveniently lives in a collocation facility about 4 miles from where i do, i opted to drop in a 3ware card. On the software side, todays software raid is superfast at least with linux and bsd, extremely flexible, and highly integrated into oss. What is the difference between a software and hardware raid. There are no advantages to fake raid or expensive real hardware raid controllers that i know of. Well supported hardware raid controller ask ubuntu. Im not a big fan of software raid on linux nor cheapie white box hardware. This site is the linux raid kernel list communitymanaged reference for linux software raid as implemented in recent version 4 kernels and earlier. Linux file systems are generally fragile enough without throwing software raid and questionable hardware into the mix. It has proven to be amazingly resilient and quite stable. The raid can be implemented either using a special controller hardware raid, or by an operating system driver software raid.
Raid contains a group or a set of arrays set of disks. If you configured the raid via software raid mdadm the use that. Comparison of software raid on windows versus linux by angsuman chakraborty, gaea news network sunday, february 18, 2007. Jun, 2016 comparing hardware raid vs software raid setups deals with how the storage drives in a raid array connect to the motherboard in a server or pc, and the management of those drives. Unfortunately, this software doesnt come with most distributions by default.
Numerous operating systems support raid configuration, including those from apple, microsoft, various linux flavors as well as openbsd. This is the raid layer that is the standard in linux2. Take a look on this document, i think its what you need. However this also fundamentally precludes integration of features into the os and file system. Raid 5 is similar to raid 4, except the parity info is spread across all drives in the array. Linux support of these sorts of devices is usually very good because theyre commonly used in enterprise situations on linux servers.
There will likely be more advanced features, such as drives being hotswappable in case of failure. While a file server setup to use software raid would likely sport a quad core cpu with 8 or 16gb of ram, the relative differences in performance. Great linux nas distro for hardware raid spiceworks. Windows software raid vs hardware raid ars technica. The basic idea of raid redundant arrays of inexpensive disks is to combine multiple small, independent disk drives into an array of disk drives which yields performance and recoverability exceeding that of a single large expensive drive sled.
I made the comment that one shouldnt run freenas on top of hardware raid, which i firmly believe. Software vs hardware raid nixcraft nixcraft linux tips. With this program, users can create a software raid array in a matter of minutes. Jul 07, 2009 a redundant array of inexpensive disks raid allows high levels of storage reliability. Aug 14, 2018 raid stands for redundant array of inexpensive disks. Software raid in the real world backdrift backdrift. Apr 05, 2019 hardware raid has the ability to take a group of drives and make it appear as a single drive. Linux server this forum is for the discussion of linux software used in a server related context. In a hardware raid setup, the drives connect to a raid controller card inserted in a fast pciexpress pcie slot in a motherboard. All of these linux raid benchmarks were carried out in a fullyautomated manner using the opensource phoronix test suite benchmarking software.
For things like simple mirroring raid1 the data just needs to be written twice and the drive controller can do that itself with instructions from the kernel so no need to get cpu involved at all. But the real question is whether you should use a hardware raid solution or a software raid solution. In this tutorial, well be talking about raid, specifically we will set up software raid 1 on a running linux distribution. Im a sysadmin by trade and as such i deal with raid enabled servers on a daily basis. This integration is really what has allowed software raid to dramatically outpace hardware raid. I have to say im very impressed with openmediavault. Aug 15, 2016 all of these linux raid benchmarks were carried out in a fullyautomated manner using the opensource phoronix test suite benchmarking software. This howto describes how to use software raid under linux. It is generally fine, however, to use windows software raid on simple storage.
Ive been hoping other people would post with some experience, because im in the middle of a decision and am leaning toward software but just basically fear the unknown. It is used to improve disk io performance and reliability of your server or workstation. With hardware raid, because the processing work is done on a discrete controller card in the server or at the level of the storage subsystem, theres no added load to the server processor and buses. We list the pros and cons of hardware vs software raid to help you decide which one is best for you. The performance of a softwarebased array depends on the server cpu performance and load.
How to get details of raid devices both soft and hard. Mar 14, 2019 difference between software raid and hardware raid in high level is presented in this video session. For this reason, users regularly create a software raid on linux to satisfy their large data needs. Over the years, ive configured and happily used linux software raid on numerous servers. The advantage of software raid is that your raid sets are not dependent on a certain controller or format and that you receive bugfixes and software updates easily through the software update process. Im about to start a new server build for home media storage.
Its a common scenario to use software raid on linux virtual machines in azure to present multiple attached data disks as a single raid device. Mdadm is a commandline utility that allows for quick and easy manipulation of raid devices. Of course, the methodology will very much depend on your final goal. I am assuming you mean hardware raid with lvm on top, vs. It should replace many of the unmaintained and outofdate documents out there such as the software raid howto and the linux raid faq. Selfbuilt nas wfreenas and a hardware raid controller. We can use full disks, or we can use same sized partitions on different sized drives. Linux software raid often called mdraid or mdraid makes the use of raid possible without a hardware raid controller. Want to get an idea of what speed advantage adding an expensive hardware raid card to your new server is likely to give you. In testing both software and hardware raid performance i employed six 750gb samsung sata drives in three raid configurations 5, 6, and 10. Areca and lsi hardware raid controllers, and with intel, amd and even via hostraid i was pretty surprised when i connected a 250gb hard drive from some old amd desktop box to a hp g1 microserver, and the controller told me that raid is degraded. Sep 30, 2018 with this program, users can create a software raid array in a matter of minutes. But with budget favoring the software raid, those wanting optimum performance and efficiency of raid will have to go with the hardware raid.
Hardware raid has the ability to take a group of drives and make it appear as a single drive. Wayne is right, if youre using linux, kernels soft raid works like charm. How to set up software raid 1 on an existing linux distribution. Setting up a storage pool has gotten easier on linux over the years, thanks to tools like mdadm. It is going to be for low performance file serving so performance is not a big issue, only reliability. Software vs hardware raid performance and cache usage server. A raid can be deployed using both software and hardware. Raid stands for r edundant a rray of i nexpensive d isks. There are many raid levels such as raid 0, raid 1, raid 5, raid 10 etc.
How to set up software raid 1 on an existing linux. This became necessary since i am running linux and windows in parallel and now need the redundancy for both os im am going to use raid1. It combines multiple inexpensive, small disk drives into an array of disks in order to provide redundancy, lower latency maximizing the chanc. How to create a software raid 5 in linux mint ubuntu. A redundant array of inexpensive disks raid allows high levels of storage reliability. I am trying to build a raid array only for reliability.
Not to mention the performance hit under heavy io not having a dedicated hardware controller handling all the striping and parity operations. Hardware raid is handled by a specialized raid controller card which does its own processing to make many devices act like one. I have written another article with comparison and difference between various raid types using figures including pros and cons of. Flexibility is the key advantage of an open source software raid, like linux mdadm, but may require a specialized skillset for proper. My experience with hardware and fake hardware raid is that as long as you stay with the same vendor, the raid metadata will be recognized ive seen this when moving drives between various hp, areca and lsi hardware raid controllers, and with intel, amd and even via hostraid i was pretty surprised when i connected a 250gb hard drive from some old amd desktop box to a hp g1 microserver, and. Ive ordered an areca 1280ml 24 port sata controller.
Configuring hybrid software raid 10 requires a lot of surplus disk hardware, although it provides a fast and. I will explain this in more detail in the upcoming chapters. Lets start the hardware vs software raid battle with the hardware side. It addresses a specific version of the software raid layer, namely the 0. Bsd opensolaris and linux raid software drivers are open source. Feb 28, 2018 raid redundant array of independent disks is one of the popular data storage virtualization technology. For software raid i used the linux kernel software raid functionality of a system running 64bit fedora 9. This is the raid layer that is the standard in linux 2. Theres nothing inherently wrong with cpuassisted aka software raid, but you should use the software raid that. Hardware raid versus software raid red hat enterprise linux.
Whether software raid vs hardware raid is the one for you depends on what you need to do and how much you want to pay. The software raid works on partition level and it can sometime increase complexity if you mix different partitions and hardware raid. Read chapter 9, redundant array of independent disks raid first to learn about raid, the differences between hardware and software raid, and the differences between raid 0, 1, and 5. My own tests of the two alternatives yielded some interesting results. Raid allows you to turn multiple physical hard drives into a single logical hard drive. Hardware raid will cost more, but it will also be free of software raid s. The performance of a software based array depends on the server cpu performance and load. I am currently planning to buy a hardware raid controller. Pricing and hardware features are going to be your real delimiters here. Firstly linux software raid is so well written in the kernel now that very little of the traffic actually hits the cpu. An overview of the steps required to configure raid include. Difference between software raid and hardware raid in high level is presented in this video session. First you need to have a linux distribution installed on your hard drive. This card is either configured through bios extensionsyou may get an extra hit esc to setup message on boot or through proprietary utilities.
Where that processing occurs can be important depending on the complexity of your raid setup. It is a way to virtualize multiple, independent hard disk drives into one or more arrays to improve performance, capacity and reliability. Software vs hardware raid nixcraft linux tips, hacks. Someone told me that linux s software raid was less reliable than hardware raid. In a hardware raid setup, the drives connect to a special raid controller inserted in a fast pciexpress pcie slot in a motherboard. For this purpose, the storage media used for this hard disks, ssds and so forth are simply connected to the computer as individual drives, somewhat like the direct sata ports on the motherboard. If so, i always advise to opt for hardware based raid first. You have to keep in mind that if hardware raid is broken, you need to rebuild the raid with the same hardware vendor. Selfbuilt nas wfreenas and a hardware raid controller guys, i am just starting to do research and spec out a desktop nas freenas but as i read more into it i found that mobo raid controllers i plan to do 4x3tb raid5 are considered evil of all sorts, so they encourage people to get a controller.
Motherboard raid, also known as fake raid, is almost always merely biosassisted software raid, implemented in firmware and is closedsource, proprietary, nonstandard, and often buggy, and almost always slower than the timetested and reliable software raid found in linux. Linux md raid is exceptionally fast and versatile, but linux io stack is composed of multiple independent pieces that you need to carefully. So raid is kind of a method for improving the performance and reliability of your storage media by using multiple drives. Hardware and software raid are two different worlds. Comparison of software raid on windows versus linux. Reasons for using software raid versus a hardware raid setup. Software raid, as you might already know, is usually builtin on your os and unlike a hardware raid, you will need to spend a little extra on a controller card. What is the difference between hardware raid and software. Unlike hardware raid, software raid uses the processing power of the operating system in which the raid disks are installed. Raid redundant array of independent disks is one of the popular data storage virtualization technology. It sounds like you configured the raid via the bios though so definitely use that. The softwareraid howto linux documentation project.
I do agree though, that hardware raid is the best choice on business class windows servers or even important. Software raid is a type of raid implementation that utilizes operating systembased capabilities to construct and deliver raid services. We just need to remember that the smallest of the hdds or partitions dictates the arrays capacity. The best way to create a raid array on linux is to use the mdadm tool. So i guess thats the difference between mounting a raid as a drive in linux wcontroller vs zfs with freenas presenting them like a raid but writingreading like nas without the controller. Apr 28, 2017 how to create a software raid 5 on linux. But with budget favoring the software raid, those wanting optimum performance and. If you are working as a linux system administrator or linux system engineer or you are already a storage engineer or you are planning to start your career in field of linux or you are preparing for any linux certification exam like rhce or you are preparing for linux admin interview then the the understanding of concept of raid become so important for you along with its configuration. I have written another article with comparison and difference between various raid types using figures including pros and cons of individual raid types so that you can make an informed decision before choosing a raid type for your system. Then you are going to grab two hard drives which will be named devsdb and devsdc in this post. Jan 25, 2020 steps to configure software raid 5 array in linux using mdadm. With todays faster cpus, software raid outperforms hardware raid. In this article i will share the steps to configure software raid 5 using three disks but you can use the same method to create software raid 5 array for more than 3 disks based on your requirement. You can benchmark the performance difference between running a raid using the linux kernel software raid and a hardware raid card.
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