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. Unlike hardware raid, software raid uses the processing power of the operating system in which the raid disks are installed. If you configured the raid via software raid mdadm the use that. This tutorial explains how to view, list, create, add, remove, delete, resize, format, mount and configure raid levels 0, 1 and 5 in linux step by step with practical examples. Software vs hardware raid nixcraft linux tips, hacks. Softwareraid gegen hardwareraid im benchmarkvergleich. Obviously performance of hardware raid vs software raid relies immensely on the controllers used in either case. 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.
Flexibility is the key advantage of an open source software raid, like linux mdadm, but may require a specialized skillset for proper. This is a method of improving the performance and reliability of your storage media by using multiple drives. Difference between software raid and hardware raid in high level is presented in this video session. Raid stands for redundant array of inexpensive disks. Recovery is easier on linux software raid and downtime was less on linux software raid as well. Today we dive into what the differences are and whe we choose them. So if iorom is software, and if i recall correctly linux os raid is hardware raid and therefore if iorom software raid fails you lose all data but with linux os hardware raid if the raid is lost, your data is recoverable. It sounds like you configured the raid via the bios though so definitely use that. The software raid works on partition level and it can sometime increase complexity if you mix different partitions and hardware raid. I have scoured through articles written about tuning software and i have used linux software raid for over 10 years. In a hardware raid setup, the drives connect to a special raid controller inserted in a fast pciexpress pcie slot in a motherboard. Linux support of these sorts of devices is usually very good because theyre commonly used in enterprise situations on linux servers.
Apple mac os x, hp hpux, ibm aix, linux, microsoft windows ab windows. Given that you can safely move the entire enclosure from one server to another with the raid intact but youd have to make sure your new server knew to use it e. Im a sysadmin by trade and as such i deal with raid enabled servers on a daily basis. Wayne is right, if youre using linux, kernels soft raid works like charm. Windows has some form of software raid, but generally it is not recommended and is not easy to boot from. One performance story i can give, is with some hp servers i configured as some fairly kickass splunk servers. Windows software raid vs hardware raid ars technica. Pricing and hardware features are going to be your real delimiters here. Hardware raid if provided by the enclosure as opposed to an adapter in your server can vary by vendor. So if i recall correctly, software raid would for an example is to be utilizing a intel option rom raid controller. Vmware doesnt support software raid at all to my knowledge, and so its not an option there. 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. We just need to remember that the smallest of the hdds or partitions dictates the arrays capacity.
In a hardware raid setup, the drives connect to a special raid controller inserted in a fast pciexpress pcie. You have to keep in mind that if hardware raid is broken, you need to rebuild the raid with the same hardware vendor. A brief history of raid raid has been around since 1970s 1989 berkeley paper was a taxonomy 1989 witnessed the first raid 5 in software 1990s saw many hardware raid 3, 5s lsi, 3ware, maxstrat, highpoint, intel 1990s also saw the introduction of raidframe mdraid came along in 2001. The linux software raid stack is just as much of a component as a hardware card, and its failure modes are numerous and amusing except when you get. From a pure operations perspective, there is very little difference between hardware and software raid. How to set up a software raid on linux addictivetips.
A redundant array of inexpensive disks raid allows high levels of storage reliability. Raid 5 vs raid 10 performance and other raid levels. For this reason, users regularly create a software raid on linux to satisfy their large data needs. But i have problem deciding that should i use hardware raid raid6 or zfs based raidz2. We list the pros and cons of hardware vs software raid to help you. It is generally fine, however, to use windows software raid on simple storage.
So raid is kind of a method for improving the performance and reliability of your storage media by using multiple drives. The performance of a software based array depends on the server cpu performance and load. Sorry for my bad english, but its crazy always setup software raid i whanna hardware raid and when i can find solution. Hardware raid and software raid are both important storage tools that we use with our systems. 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. Fake raid is raid that is at least partially implemented in software in the driver itself, rather than in hardware. Software raid is part of os, so no need to spend extract money. Some of these are supported on linux using the driver. Hardware raid vs software raid, is hardware raid portable. I do agree though, that hardware raid is the best choice. Software vs hardware raid performance and cache usage server.
With this program, users can create a software raid array in a matter of minutes. Hardware raid has the ability to take a group of drives and make it appear as a single drive. Setting up a storage pool has gotten easier on linux over the years, thanks to tools like mdadm. There are no advantages to fake raid or expensive real hardware raid controllers that i know of. Well supported hardware raid controller ask ubuntu. Is there a difference between hardware raid and software raid.
On the software raid side, the ext3 configuration is the same as the ext3alignwb hardware configuration, the plain xfs option the same as hardxfsalign, and the xfslogalign the same as the xfsdlalign hardware configuration. Hardware raid will cost more, but it will also be free of software raid. Numerous server oses support raid configuration, including those from apple, microsoft, various linux flavours as well as openbsd, freebsd. Ive been hoping other people would post with some experience, because im in the middle of a decision and am leaning toward software but.
The drives are configured, so that the data is either divided between disks to distribute load, or duplicated to ensure that it can be recovered once a disk fails. However, there are certain limitations of a software raid. Ultimately, the difference comes down to where the raid processing is performed. I have had to recover from failed disks and completely failed arrays with both high end raid cards and linux software raid. Ive used software raid as well, only in raid0, and it worked flawlessly in suse linux and still use software raid 1 in suse 9. Hardware raid, explains how these different raid implementations work and the benefits of each implementation, and. Difference between hardware raid and software raid. First, there are operating systems where software raid does not function, or does not function as well as linux mdadm.
The linux kernel contains an md driver that allows the raid solution to be completely hardware independent. Linux file systems are generally fragile enough without throwing software raid and questionable hardware into the mix. Windows software raid has a bad reputation, performance wise, and even storage space seems not too different. Most motherboard integrated raid is not hardware raid. The hardware based system manages the raid subsystem independently from the host and presents to the host only a single disk per raid array.
Linux uses either the md raid or lvm for a software raid. A raid can be deployed using both software and hardware. No hotswap is possible with software alone, without a hardware support. We have explained what raid is and the two types of raid, today we want to discuss the difference between hardware raid and software raid, as many users have been confused by them brief introduction about hardware raid. 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.
Firstly linux software raid is so well written in the kernel now that very little of the traffic actually hits the cpu. Software raid can never be faster it is at best as fast for stupid raid types, like striping than hardware raid unless those who implemented the hardware raid were a bunch of rabid chimps on acid. Take a look on this document, i think its what you need. But the real question is whether you should use a hardware raid solution or a software raid. It is a way to virtualize multiple, independent hard disk drives into one or more arrays to improve performance, capacity and reliability. Most of these only work in windows since they are driver dependent. Im not a big fan of software raid on linux nor cheapie white box hardware. It can either be performed in the host servers cpu software raid, or in an external cpu hardware raid. This integration is really what has allowed software raid to dramatically outpace hardware raid. It is not possible to boot an operating system from a software raid0 or raid5. Software vs hardware raid performance and cache usage. What is the difference between hardware raid and software. With todays faster cpus, software raid outperforms hardware raid.
How to create a software raid 5 in linux mint ubuntu. Just trying to get some feedback from anyone with experience with hardware vs software raid especially on an openvz platform. 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 is great if you have the money, and the space my adpatec 2100s is a. When running basic io tests ddoflagdirect 5k to 100g files, hdparam t, etc.
However this also fundamentally precludes integration of features into the os and file system. Additionally, hardware assisted software raid usually comes with a variety of drivers for the most popular operating systems, and therefore, is more os independent than pure software raid. 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. The hardware based array manages the raid subsystem independently from the host and presents to the host only a single disk per raid array. You can benchmark the performance difference between running a raid using the linux kernel software raid and a hardware raid.
Bsd opensolaris and linux raid software drivers are open source. There will likely be more advanced features, such as drives being hotswappable in case of failure. There is no real advantage in using these on linux, i suggest to stick with the linux raid. Today a server with a hardware raid controller reported when i say reported i actually mean lit a small red led on the front of the machine a bad disk, which is not uncommon. Not to mention the performance hit under heavy io not having a dedicated hardware controller handling all the striping and parity operations. In testing both software and hardware raid performance i employed six 750gb samsung sata drives in three raid. The problem well at least usually is that the drivers required arent open sourced and are not usually available for linux based systems. Software vs bios vs hardware raid ars technica openforum. Yes, hardware raid can be a bit faster but with a sufficiently powerful system, those speed gains become close to imperceptible. For software raid i used the linux kernel software raid functionality of a system running 64bit fedora 9. We can use full disks, or we can use same sized partitions on different sized drives. Ive used mdadm and lvm raids in production since about 2004 without data loss and you backup anyway right. 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.894 979 803 522 879 2 1522 676 932 101 139 1054 171 1113 163 1094 837 476 1274 1361 1213 805 1038 768 1295 1126 1182 1248 1189 1384 1212 924 260 1040