Hardware raid solutions exist that operate as dedicated devices, usually as pci expansion cards or directly on the motherboard. It offers the cheapest possible solution, as expensive disk controller cards or hot swap chassis are not required. 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. It can either be performed in the host servers cpu software raid, or in an external cpu hardware raid. Since you mention server most likely there is hardware raid present. Software raid can have trouble with dissimilar drives. Its also important to note that hotswap raid is a hardware raid solution and is very different from the software raid options you can utilize with builtin utilities in operating. The linux kernel contains an md driver that allows the raid solution to be completely hardware independent.
Software raid is a type of raid implementation that utilizes operating systembased capabilities to construct and deliver raid services. Another limitation of linux software raid is expanding raid groups. Recently support for these devices was added into the linux kernel but i am not sure how well it. Hot spare hard drives are drives that are kept in reserve in a raid array to allow them to function as emergency replacements in the event of a raid volume drive failure. You may need to run a command to add the new device. The raid implementation in winxp in my opinion is flawed to the point of making it unusable. Software raid, on the other hand, implements the various raid levels in the kernel disk block device code and offers the cheapest possible solution, as expensive disk controller cards or hot swap chassis are not required. Also, true hardware raid controller are often rather expensive, so if someone customized the system, then it is very likely that choosing a hardware raid setup made a very noticeable change in the computers price. But with budget favoring the software raid, those wanting optimum performance and efficiency of raid will have to go with the hardware raid.
This howto describes how to use software raid under linux. That duplication also makes hardware raid more expensive than software raid. Nov 16, 2007 another limitation of linux software raid is expanding raid groups. It sounds like you configured the raid via the bios though so definitely use that. This is the raid layer that is the standard in linux2.
A hp server that i work on had two disks in a raid 1 array, one of my colleagues added an extra disk and made it a raid 5, the hardware raid device moved the data around as appropriate while the machine was running and the disk space was expanded without any downtime. The ability to hot swap drives in the event of a failure. The independent disks attach to the hardware interface. May 28, 2001 its also important to note that hotswap raid is a hardware raid solution and is very different from the software raid options you can utilize with builtin utilities in operating. May 24, 2005 scott lowe responds to a techrepublic discussion and one members raid dilemma. Jan 17, 2010 linux software raid hot swap disk replacement posted on january 17, 2010 january 17, 2010 by andy one of bitfolks servers in the us has had first one and then two dead disks for quite some time. It offers the cheapest possible solution, as expensive disk controller cards or hot swap chassis 2 are not required. Dec 25, 2006 software raid is generally slower and less reliable than a hardware solution. This is an animated video explaining different raid levels. Hardware raid controllers have no specific raid subsystem in linux. 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. What is the difference between hardware, software, and.
Raid 1e requires min of 3 disk, and raid 10 requires a min of 4 disk. In a true hardware raid, the operating system simply writes data to the hardware raid controller which handles the multiplicitous. Dec 01, 2014 that duplication also makes hardware raid more expensive than software raid. I still prefer having raid done by some hw component that operates independently of the os. Hot swap capable raid expansion to take advantage of the software raid feature on the pip platform cpu boards, mpl created the hsraid 12 options. It offers the cheapest possible solution, as expensive disk controller cards or hotswap chassis are not required. Linux software raid hot swap disk replacement strugglers. Has anyone had any experience or knowledge about installing linux on hardware raid 0. Plug them in and they behave like a big and fast disk. This new solution is a user friendly and easy option to build a hot swap capable raid system inside the pip housing perfect for a raid1 array. Software raid implements the various raid levels in the kernel block device code. In order to use software raid we have to configure raid md device which is a.
There is great software raid support in linux these days. Redundant array of independent disks english and hindi captions. But with budget favoring the software raid, those wanting optimum performance and. The classic raidtools are the standard software raid management tool for linux, so using mdadm is not a must.
In order to use software raid we have to configure raid md device which is a composite of two or more storage devices. The performance of a softwarebased array depends on the server cpu performance and load. Replacing failed disk is simple just plug it out and put in a new one. The softwareraid howto linux documentation project. In a hardware raid setup, the drives connect to a raid controller card inserted in a fast pciexpress pcie slot in a motherboard. Linux provides md kernel module for software raid configuration.
I believe it is possible to make it automatic, but in the places where i use it manually running the command to add the new drive has never been a problem. Apr 16, 20 hot spare hard drives are drives that are kept in reserve in a raid array to allow them to function as emergency replacements in the event of a raid volume drive failure. A raid can be deployed using both software and hardware. Regarding raid1e and 10 the main difference between 1e and 10 is that 1e uses an odd number of disk for providing protection, where as 10 uses an even number of disk. The state of the active linux software raid devices can be viewed by running.
Buying a hard drive with the biggest cache will not help in raid stripping levels. Its slightly specific to the hardware i use i wrote it for internal use but can easily be adapted to be more generic. You can set up raid in a swap file on a filesystem on your raid device, or you can set up a raid device as a swap partition, as you see fit. 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. Firstly linux software raid is so well written in the kernel now that very little of the traffic actually hits the cpu. It offers the cheapest possible solution, as expensive disk controller cards or hotswap chassis 2 are not required. I do not think the hard drive cache is ever used in linux anyways. 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. With todays faster cpus, software raid outperforms hardware raid.
Jul 07, 2009 a redundant array of inexpensive disks raid allows high levels of storage reliability. Hotswap support is spotty not all software raid implementations support hot swapping. For software raid i used the linux kernel software raid functionality of a system running 64bit fedora 9. In a hardware raid setup, the drives connect to a special raid controller inserted in a fast pciexpress pcie slot in a motherboard. Typical examples include disk hot plug, array level migration and online capacity expansion. There will likely be more advanced features, such as drives being hotswappable in. A hardware raid is the only option if you want to take advantage of hot swapping because it relies on a piece of hardware called a hot swap backplace that makes hot swapping possible. Hot swapping and hot plugging are terms used to describe the functions of replacing computer system components without shutting down the system. The linux kernel contains an md driver that allows the raid solution to be.
Operating system will access raid device as a regular hard disk, no matter whether it is a software raid or hardware raid. Linux software raid hot swap disk replacement posted on january 17, 2010 january 17, 2010 by andy one of bitfolks servers in the us has had. 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. Hot swap support is spotty not all software raid implementations support hot swapping. Ive always installed linux dual boot with windows on the hdd, to avoid raid complications, but after learning more about hardware vs software raid, im wondering if this makes a difference. The ability to hotswap drives in the event of a failure. Linux software raid disc replacement procedure web and. Ive written a document on using linux software raid with hotswap scsi hardware. Expensive disk controller cards or hotswap chassis are not required, and software raid works with cheaper ide disks as well as scsi disks. The classic raidtools are the standard software raid management tool for. A redundant array of inexpensive disks raid allows high levels of storage reliability. 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. Here are some tips on raid levels and some feedback on the software vs.
New nvme enabled hardware raid hbas are new to the market as well. In testing both software and hardware raid performance i employed six. A menudriven setup wizard so production can often begin right out of the box. 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 g1 microserver, and. If you want the system to access multiple files at once, put two hardware raid 5 arrays in software raid 1. Software vs hardware raid nixcraft linux tips, hacks. Lowend hardware raid vs software raid server fault. A linux software raid tutorial oakton community college. It addresses a specific version of the software raid layer, namely the 0.
Hardware redundant array of inexpensive disks raid and software raid are two main ways for setting up raid system. It is basically an ata1003 ide controller with a few extra functions and a software driver and bios that handles raid. I have a zfs raid 10 software raid as my primary storage setup and the read speeds i get are more than enough to saturate my gigabit ethernet. Software vs hardware raid nixcraft nixcraft linux tips.
Software raid implements the various raid levels in the kernel disk block device code. Raid stands for redundant array of inexpensive disks. Software raid is part of os, so no need to spend extract money. It is a way to virtualize multiple, independent hard disk drives into one or more arrays to improve performance, capacity and reliability. In testing both software and hardware raid performance i employed six 750gb samsung sata drives in three raid configurations 5, 6, and 10. The software raid works on partition level and it can sometime increase complexity if you mix different partitions and hardware raid. Intel vroc is a data center quality product with performance and cpu utilization metrics befitting such applications. If you want the system to access multiple files at once, put two hardware raid5 arrays in software raid1. Software raid in linux is implemented by the multiple devices md driver. Theoretically if you have a hardware raid 1, software striping could be less efficient, but unless you have unusual applications where reading from swap is overwhelmingly more common than writing to it, i would expect a nonraid software striped swap to outperform a swap partition on a raid 1. Hardware raid cards introduce an additional device within the system, that singularly may fail itself, but by introducing this additional card it is able to offload the parity calculations from maintaining the raid off of the cpu. But the real question is whether you should use a hardware raid solution or a software raid solution.
Performance does vary depending on configuration and testing parameters, but generally, data transfer rates are comparable between the two technologies. Satasas hotplug support is required by the satasas specifications, therefore satasas platform is the one where hotplug should be least problematic. Software raid also works with cheaper ide disks as well as scsi disks. Hardware raid controllers appear in this list, but fakeraid implementations do not. Does it change the way i need to partition the drive. Software raid is generally slower and less reliable than a hardware solution. If properly configured, theyll be another 30% faster. Ive actually had up to 3 hd movies streaming off the array simultaneously with no issues and not even putting a dent in what the setup can do. Firmware raid also known as ataraid is a type of software raid where the raid. Hardware raid has made significant advances in recent years including. A hp server that i work on had two disks in a raid1 array, one of my colleagues added an extra disk and made it a raid5, the hardware raid device moved the data around as appropriate while the machine was running and the disk space was expanded without any downtime. The linux kernel contains a multidisk md driver that allows the raid. As hardware raid requires additional controller hardware.
Choosing between software raid and hardware raid depends on. The ssd7120s unique hardware architecture provides dedicated pcie 3. Windows software raid vs hardware raid ars technica. I have a dell server that has a software raid 5 configuration. If you configured the raid via software raid mdadm the use that. The problem is your promise raid controller is not a hardware raid controller. It is used to improve disk io performance and reliability of your server or workstation. Theoretically if you have a hardware raid 1, software striping could be less efficient, but unless you have unusual applications where reading from swap is overwhelmingly more common than writing to it, i would expect a non raid software striped swap to outperform a swap partition on a raid 1. I have hot swapped drives using the software raid builtin into the linux kernel on many occasions. Frequently asked questions about intel virtual raid on cpu.