If you configured the raid via software raid mdadm the use that. Ive been using software raid but ive noticed linux reporting high memory usage. The raid can be implemented either using a special controller hardware raid, or by an operating system driver software raid. All of their functions are done through the operating system. The mdadm tool patience, pizza, and your favorite caffeinated beverage. Linux md raid is different than windows software raid, which is different than something like zfs. Linux md raid is exceptionally fast and versatile, but linux io stack is composed of multiple independent pieces that you need to carefully. With todays fast cpus, software raid performance can excel against hardware raid. It offers the cheapest possible solution, as expensive disk controller cards or hotswap chassis 1 are not required. With todays faster cpus, software raid outperforms hardware raid. Hardware raid offers better reliability compared to software raid. When storage drives are connected directly to the motherboard without a raid controller, raid configuration is managed by utility software in the operating system, and thus referred to as a software raid setup. In order to use software raid we have to configure raid md device which is a composite of two or more storage devices. Software raid is part of os, so no need to spend extract money.
Raid stands for redundant array of inexpensive disks. Raid 1 or raid 10 solutions work fairly well even without expensive hardware raid controllers and can be acquired relatively inexpensively. I assume that the 975x is essentially a hardwareassisted software raid solution, but i cannot find any difinitive information on this. The software raid works on partition level and it can sometime increase complexity if you mix different partitions and hardware raid. Comparison hardware raid versus software raid in regards to a variety of considerations. A software raid can be prone to data corruption, due to the fault of the raid software or driver that is being used. It combines multiple inexpensive, small disk drives into an array of disks in order to provide redundancy, lower latency maximizing the chanc. The hardware based array manages the raid subsystem independently from the host and presents to the host only a single disk per raid array. My experience with hardware and fakehardware 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. Aug 14, 2018 raid stands for redundant array of inexpensive disks.
If properly configured, theyll be another 30% faster. But the real question is whether you should use a hardware raid solution or a software raid solution. It is generally fine, however, to use windows software raid on simple storage. So it looks like hardware raid 10 is the winner for windows setup providing you can replace the card in event of failure, and software raid 10 is a viable option for linux etc. Beyond that, hardware raid usually has at least options for battery backed or newer capacitorflash based write caches. The linux kernel contains an md driver that allows the raid solution to be completely hardware independent. 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. This is a method of improving the performance and reliability of your storage media by using multiple drives. This document will discuss a variety of factors to consider when choosing between hardware and software raid configurations on linux workstations. Other than that, using a 1,024kb chunk size removes the block output advantage that the raid card had for the 256kb chunk size raid6.
Software vs hardware raid nixcraft nixcraft linux tips. Software vs hardware raid nixcraft linux tips, hacks. But with budget favoring the software raid, those wanting optimum performance and efficiency of raid will have to go with the hardware raid. Raid redundant array of independent disks is one of the popular data storage virtualization technology. I decided to go with software raid rather than using the hardware option of the sans enclosure. The performance of a software based array depends on the server cpu performance and load. Solutions like zfs can perform better than hardware because they leverage the servers ram and cpu resources. It can either be performed in the host servers cpu software raid, or in an external cpu hardware raid.
Software raid implements the various raid levels in the kernel disk block device code. Hardware raid versus software raid red hat enterprise linux. Although most of this should work fine with later 3. Monitoring consistency nagios uses the same checking. May 29, 2015 find hardware raid information linux, how to know hardware raid through commandline, how to check raid status, how to determine raid drive configuration, get info on hardware raid controllers, get details of raid configuration, how to determine raid controller type and a model, check hardware raid configuration command in linux, linux and. Comparison of software raid on windows versus linux by angsuman chakraborty, gaea news network sunday, february 18, 2007. Bsd opensolaris and linux raid software drivers are open source. 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. Hardware raid will cost more, but it will also be free of software raid s. It also permits users to reconfigure arrays without being restricted by the hardware raid controller. It means more people can fix problems as compare to a closed source. Soft possibly the longest running battle in raid circles is which is faster, hardware raid or software raid. Hardware and software raid are two different worlds. Hardware raid controllers have their own processors, and some have their own memory.
It is usually os agnostic, so volumes are not specific to an os file system like software raid. A raid 1 will write in the same time the data to both disks taking twice as long as a raid 0, but can, in theory read twice as fast, because will read from one disk a part of the data and from another the other part, so raid 1 is not twice as bad as raid 0, both have their place. The problem is your promise raid controller is not a hardware raid controller. 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. 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. System performance hardware raid may better balance system performance through asynchronous performance and.
It is a way to virtualize multiple, independent hard disk drives into one or more arrays to improve performance, capacity and reliability. There is great software raid support in linux these days. Comparison of software raid on windows versus linux. 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. Aug 15, 2006 before raid was raid, software disk mirroring raid 1 was a huge profit generator for system vendors, who sold it as an addon to their operating systems. An example of a hardware raid device would be one that connects to a scsi controller and presents the raid arrays as a single scsi drive. Unlike hardware raid, software raid uses the processing power of the operating system in which the raid disks are installed. 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.
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. This table summarizes the key differences between hardware. A raid can be deployed using both software and hardware. Difference between software raid and hardware raid in high level is presented in this video session. Jun, 2016 in a hardware raid setup, the drives connect to a special raid controller inserted in a fast pciexpress pcie slot in a motherboard. Hardware raid and implications for the future duration. Flexibility is the key advantage of an open source software raid, like linux mdadm, but may require a specialized skillset for proper.
Differences between hardware raid, hbas, and software raid. Numerous server oses support raid configuration, including those from apple, microsoft, various linux flavours as well as openbsd, freebsd. Plus, software raid permits users to reconfigure your arrays without being restricted by the hardware raid controller. A redundant array of inexpensive disks raid allows high levels of storage reliability. 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. I still prefer having raid done by some hw component that operates independently of the os. Hardware agnostic you can pull the disks out of one machine and put them into another without needing to find the same proprietary raid controller live management you can manipulate the array on the live system e. 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. Or raid 1 if you only need the speedcapacity of a single pair. Where possible, information should be tagged with the minimum. Raid arrays that you create through software or operating systems are software based raid. With hardware raid, this is offloaded to the storage controller and the main cpu is not involved in maintaining the raid. The cost is lower because no additional hardware raid controller is required.
Software versus hardware software raid has the advantage of flexibility software raid can take advantage of cpu software raid can be integrated with other storage software encryption, dedup, etc software raid can easily be updated hardware is vendor supported software raid is less expensive. Lets start the hardware vs software raid battle with the hardware side. Operating system will access raid device as a regular hard disk, no matter whether it is a software raid or 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. Software vs hardware raid performance and cache usage server. Conclusion this was a big article to write for an evening, but hopefully it helps people understand the general implications of different raid implementations. It should replace many of the unmaintained and outofdate documents out there such as the software raid howto and the linux raid faq. The hardwarebased array manages the raid subsystem independently from the host and presents to the host only a single disk per raid array.
Software raid, on the other hand, implements the various raid levels in the kernel disk block device code and. With the advent of hardware raid systems the battle was joined until the hardware array emerged victorious. Linux software raid often called mdraid or mdraid makes the use of raid possible without a hardware raid controller. 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. This site is the linux raid kernel list communitymanaged reference for linux software raid as implemented in recent version 4 kernels and earlier. I do agree though, that hardware raid is the best choice. Since you mention server most likely there is hardware raid present.
A kernel with the appropriate md support either as modules or builtin. Software raid virtually belongs to operating system. Hardware versus software raid on linux workstations. 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. It uses hardware raid controller card that handles the raid tasks transparently to the operating system. Whether software raid vs hardware raid is the one for you depends on what you need to do and. Linux provides md kernel module for software raid configuration.
Software vs hardware raid performance and cache usage. 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. 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. Reasons for using software raid versus a hardware raid setup. It is used to improve disk io performance and reliability of your server or workstation. Plug them in and they behave like a big and fast disk. I have scoured through articles written about tuning software and i have used linux software raid for over 10 years. There are no advantages to fake raid or expensive real hardware raid controllers that i know of. Numerous operating systems support raid configuration, including those from apple, microsoft, various linux flavors as well as openbsd.
Aug 25, 2010 so it looks like hardware raid 10 is the winner for windows setup providing you can replace the card in event of failure, and software raid 10 is a viable option for linux etc. It sounds like you configured the raid via the bios though so definitely use that. Windows software raid vs hardware raid ars technica. Before raid was raid, software disk mirroring raid 1 was a huge profit generator for system vendors, who sold it as an addon to their. The md driver in the linux kernel is an example of a raid solution that is completely hardware independent. It is basically an ata1003 ide controller with a few extra functions and a software driver and bios that handles raid. When running basic io tests ddoflagdirect 5k to 100g files, hdparam t, etc. Jul 07, 2009 a redundant array of inexpensive disks raid allows high levels of storage reliability.
For software raid i used the linux kernel software raid functionality of a system running 64bit fedora 9. Software raid also works with cheaper ide disks as well as scsi disks. So the only way to tell if a drive is failing is to go the software route. The performance of the hardware raid is about 1015mbsec better for rewrite from the software raid s 5560mbsec total. Sans does not provide any method of monitoring the array via linux only windows or os x. In a hardware raid setup, the drives connect to a raid controller card inserted in a fast pciexpress pcie slot in a motherboard.
With bios raid, the cpu is used to maintain the raid structure. What is the difference between a software and hardware raid. Heavy processing can cause some pieces of data to be delayed by a small amount of time. Hardware raid is great if you have the money, and the space my adpatec 2100s is a. Difference between hardware raid and software raid.
Bios raid is restricted to the devices attached to the controller that offers bios raid. Ultimately, the difference comes down to where the raid processing is performed. Mar 06, 2018 it can either be performed in the host servers cpu software raid, or in an external cpu hardware raid. 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. They also use system resources because they do not have their own. A software raid can also be affected if the host computer is heavily loaded. Hardware raid is more expensive than software raid, but offers better performance and interoperability. Firstly linux software raid is so well written in the kernel now that very little of the traffic actually hits the cpu. Hardware raid is great if you have the money, and the space my adpatec 2100s is a full pcix card its huge in my atx case. Feb 28, 2018 raid redundant array of independent disks is one of the popular data storage virtualization technology.
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