Software raid has been relegated to lowend, lowcost applications where folks. So one of the simplest methods is to try time utility. It has seven modes of operation that pretty much cover any possible task you might use software raid. Aug 14, 2018 raid stands for redundant array of inexpensive disks.
I have made some testing of performance of different types of raids, with 2 disks involved. Mdadm pronounced mdadam is a tool for linux for managing software raid devices in linux. It was found that chunk sizes of 128 kib gave the best overall performance. It is used to improve disk io performance and reliability of your server or workstation. Benchmark samples were done with the bonnie program, and at all times on files. In this tutorial you will learn how to use the dd command to test disk io performance. To get accurate read test data, first discard caches before testing by running the following commands. For the raid 10 performance test i used 256kb and 1,024kb chunk sizes and the default software raid 10 layout of n2. This article will provide valuable information about which parameters should be used. For raid types 5 and 6 it seems like a chunk size of 64 kib is optimal, while for the other raid types a chunk size of 512 kib seemed to give the best results. Raid 0 is used to enhance the readwrite performance of large data sets, and to. I suggest testing out all 3 schedulers to see what one offers the best performance for. Tcq seemed to slightly increase write performance, but there really wasnt. This increases performance as the card can inform the operating system that the write is complete as soon as it hits its memory.
In the graphs comparing raid 10 of 4 drives to the performance of a single drive i see a slight increase of write performance and a 100% increase in writes. Raid 10s attractive blend of performance and redundancy does come at a price, though. In fact, the procedure for setting up a raid system has gotten so simple that many users routinely click through the commands without too much consideration for how the various. Apr 09, 2010 i set up a raid o array using 2 hd502hj samsung sata 500g 16mb to decrease boot time, 250 mb read, 240 mb write.
Chipset serial ata and raid performance compared the. A few months ago i posted an article explaining how redundant arrays of inexpensive disks raid can provide a means for making your disk accesses faster and more reliable in this post i report on numbers from one of our servers running ubuntu linux. Creating a software raid using the linux kernel is becoming easier and easier. I set up a raid o array using 2 hd502hj samsung sata 500g 16mb to decrease boot time, 250 mb read, 240 mb write. The read performance im getting is maxing out around 250 mbs used to be 170 mbs with raid5. But if we test dedupped zfs pool with pure zero or random data, there is huge performance difference.
Recently, i build a small nas server running linux for one my client with 5 x 2tb disks in raid 6 configuration for all in one backup server for linux, mac os x, and windows xpvista710 client computers. The md changes were sent in on friday and include raid10 cluster improvements, memory leak fixes, a raid10 hang fix, a raid5 block faulty device fix, a metadata updating fix, and an invalid disk. The performance of the linux kernel is often critical for the products using it. On hard disk testing random doesnt matter, because every byte is written as is also on ssd with dd. Speaking of raid levels, raid 45 will never give you good performance, that is comparing to raid0 or raid10. How to improve server performance by io tuning part 1. Chipset serial ata and raid performance compared the tech.
Contains comprehensive benchmarking of linux ubuntu 7. 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. A word of caution the examples in this article are from my test raid systems. And about the prize of hard drives, ive seen 300 gib drives at 10 euros in ebay i dont know if they are really new.
The linux community has developed kernel support for software raid. Dec 08, 2005 raid 10s attractive blend of performance and redundancy does come at a price, though. This makes it dramatically safer than raid 5, which is very important, but also imposes a dramatic write penalty. Xfs, making for a 185% speed increase for hardware over software. Trying some raid1 configurations, i want to know if the read speed is faster both on a single file and on several files. Arrays require an even number of at least four drives to implement, and capacity is limited to just half. It is used to getset hard disk parameters including test the reading and caching performance of a disk device on a linux based system.
Test hdd, ssd, usb flash drives performance hdparm is a linux command line utility that allows to set and view hardware parameters of hard disk drives. Under linux, the dd command can be used for simple sequential io performance measurements. The kernel also supports the allocation of one or more hot spare disk units per raid device. Jun 01, 20 improve software raid speeds on linux posted on june 1, 20 by lucatnt about a week ago i rebuilt my debianbased home server, finally replacing an old pentium 4 pc with a more modern system which has onboard sata ports and gigabit ethernet, what an improvement. The real performance numbers closely match the theoretical performance i described earlier. However, of all the zillions of raid controllers ive worked with ive never seen a raid 1 card improve read performance. Software vs hardware raid nixcraft linux tips, hacks. You should then ask yourself if the software raid found in linux is comprehensive enough for your system. I keep hearing that raid 1 is supposed to increase read performance because data is duplexed on both drives. Raid 10 is mirrored stripes, or, a raid 1 array of two raid 0 arrays. I am the proud user of linux software raid on my home server, but for a proper enterprise system i would try to avoid it. If you are using a very old cpu, or are trying to run software raid on a server that already has very high cpu usage, you may experience slower than normal performance, but in most cases there is nothing wrong with using mdadm to create software raids. Soft possibly the longest running battle in raid circles is which is faster, hardware raid or software raid. Iometer can do a good job modeling realworld workloads.
Improve your sata disk performance by converting from ide to ahci by jack wallen jack wallen is an awardwinning writer for techrepublic and. I ran the benchmarks using various chunk sizes to see if that had an effect on either hardware or software configurations for the. Ive been working with server based raid controllers for a long time with pretty much all raid levels. More expensive raid cards include a small amount of batterybacked storage. A raid can be deployed using both software and hardware. With software raid, you might actually see better performance with the cfq. These layouts have different performance characteristics, so it is important to choose the right layout for your workload. To help improve run times, 3 threads were used on the quadcore system. Benchmarking and stress testing is sometime necessary to optimize system performance and remove system bottlenecks caused by hardware or software. Optimize your linux vm on azure azure linux virtual. Increasing the stripe width adds more disks and can improve readwrite performance if the stripe width chunk size is greater than the data size. Performance comparison of mdadm raid0 and lvm striped. You can test our physical drives with hdparm utility e. The chunksize is the chunk sizes of both the raid 1 array and the two raid 0 arrays.
Normal io includes home directory service, mostlyreadonly large file service e. Redundant array of inexpensive disks raid is an implementation to either improve performance of a set of disks andor allow for data redundancy. Hddssd performance with mdadm raid, bcache on linux 4. In testing both software and hardware raid performance i employed six 750gb samsung sata drives in three raid configurations 5, 6, and 10. Dec 20, 2019 benchmarking and stress testing is sometime necessary to optimize system performance and remove system bottlenecks caused by hardware or software. The only real numbers of raid 10 performance relative to a single disk that i could find were in the zdnet article comprehensive raid performance report. Solutions like zfs can perform better than hardware because they. But the real question is whether you should use a hardware raid solution or a software raid solution. Raid10 is mirrored stripes, or, a raid1 array of two raid0 arrays. A redundant array of inexpensive disks raid allows high levels of storage reliability. There are many all in one dedicated benchmarking tool with a pretty gui available for linux. Mdadm is linux based software that allows you to use the operating system. Understanding raid performance at various levels storagecraft. With a call to mdadm and pvcreate, you can be well on your way to using lvm on top of a raid 5 or raid 10 device.
For those making use of linux software raid, a number of improvements are on deck to the kernels md code with the forthcoming linux 4. I evaluated the performance of a single, traditional 250 gb 3. Read performance is identical between all raid types. Improve software raid speeds on linux posted on june 1, 20 by lucatnt about a week ago i rebuilt my debianbased home server, finally replacing an old pentium 4 pc with a more modern system which has onboard sata. If data write performance is important then maybe this is for you. Testing downloads from another pc in the network is a good point to test the raid speed. Performance numbers for several configurations of storage devices. That means reading one 10gb file wont be any faster on raid1 than on a single disk, but reading two distinct 10gb fileswill be faster. This article will help you for increasing raid rebuildingresyncing speed in linux box. Learn to live with the fact that gigabit networking is slow and that 10gbe networking often has barriers to reaching 10gbps for a single test. The choice between hardware assisted and software raid seems to draw strong opinions on all sides.
Software vs hardware raid performance and cache usage server. The fourth core was kept for the software raid or lvm processing. Networking configuration can make a real difference to hyperv performance. Raid 10 may be faster in some environments than raid 5 because raid 10 does not compute a parity block for data recovery. There are plenty of tools which test the readwrite speed of a hard drive. Some raid controllers speedup read access when using raid1. Both drives, devsdb and devsdc, were used for all of the tests. So after we check that sbsize is still available, only reduce the reserved, dont increase it. We match them up to the z87c226 chipsets six corresponding ports, a handful of software based raid modes, and two operating systems to test their performance. The chunksize is the chunk sizes of both the raid1 array and the two raid0 arrays. Why speed up linux software raid rebuilding and resyncing.
As an alternative to a traditional raid configuration, you can also choose to install logical volume manager lvm in order to configure a number of physical disks into a single striped logical storage volume. Yes, linux implementation of raid1 speeds up disk read operations by a factor of two as long as two separate disk read operations are performed at the same time. The theoretical and real performance of raid 10 server. For what performance to expect, the linux raid wiki says about raid 5. Dec 05, 2017 the read performance im getting is maxing out around 250 mbs used to be 170 mbs with raid5. A lot of software raids performance depends on the cpu. 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. Same boot time same performance index in win 7 of 5. Best ways to improve vm performance in hyperv environment. I did not do test where those chunksizes differ, although that should be a perfectly valid setup.
Raid can be handled either by the operating system software or it may be implemented via a purpose built raid disk controller card without having to configure the operating system at all. And it can also be used as a simple benchmarking tool that allows to quickly find out the read speed of a disk. Software raid how to optimize software raid on linux using. Put in an intel 160 gb ssd to see some performance increase. For pure performance the best choice probably is linux md raid, but nowadays i. The linux kernel supports raid 0, raid 1, raid 4, or raid 5. Ive recently been specifying a moderatelysized storage system for a research setting.
Linux and unix test disk io performance with dd command. Some people use raid 10 to try to improve the speed of raid 1. Oct 27, 2018 for those making use of linux software raid, a number of improvements are on deck to the kernels md code with the forthcoming linux 4. In testing both software and hardware raid performance i employed six. The linux kernel is used in a wide variety of devices, from small iot devices to cloud servers. Its not obvious that raid0 will always provide better performance. If there is sufficient interest i will repeat the tests with xfs and native raid btrfs in a future article. The test was done on a supermicro aocsat2mv8 controller with 8 sata ii ports, and connected to a 32bit pci slot, which could explain the mbs max found. Monitoring and managing linux software raid prefetch.
Elements that affect performance system motherboard, chip set, bios, processor, memory system chip set and memory speed can impact benchmark performance recommend 8wide x8 pcie generation2 slot for all 6 gbs sas benchmarks operating system with latest service pack and updates raid controller firmware, bios. Mdadm is linux based software that allows you to use the operating system to create and handle raid arrays with ssds or normal hdds. Software raid how to optimize software raid on linux. In 2009 a comparison of chunk size for software raid 5 was done by rik faith with chunk sizes of 4 kib to 64 mib. What about testing a raid speed, including software raid. You can always increase the speed of linux software raid 0156.
The test were done on a controller which had an upper limit on about 350 mbs. The goal of this study is to determine the cheapest reasonably performant solution for a 5spindle software raid configuration using linux as an nfs file server for a home office. The goal of this article is mostly to provide a fresh look at the linux hddstorage performance options and now bcache would compare to a raid setup, etc. How to increase speed of software raid rebuilding in linux. May 22, 2017 redundant array of inexpensive disks raid is an implementation to either improve performance of a set of disks andor allow for data redundancy. Use dd command to monitor the reading and writing performance of a disk device. Most networking demands dont even bog down gigabit. Linux io performance tests using dd thomaskrennwiki. I am trying to do a disk performance test readwrite. Linux md raid 10 improvementsfixes queued for linux 4. For software raid i used the linux kernel software raid functionality of a system running 64bit fedora 9. In a linux system, this could be done easily with few basic command line tools. I would not recommend using devurandom because its software based and slow as pig. Arrays require an even number of at least four drives to implement, and capacity is.
Hd tune tests the speed of hard disk, so it bypass the software raid and probably the hardware raid too. Raid 6, however, is based off of raid 5 and has another level of parity. In general, software raid offers very good performance and is relatively easy to maintain. It is a way to virtualize multiple, independent hard disk drives into one or more arrays to improve performance, capacity and reliability. We match them up to the z87c226 chipsets six corresponding ports, a handful of softwarebased raid modes, and two operating systems to test their performance. The raid can be implemented either using a special controller hardware raid, or by an operating system driver software raid. For more detailed io performance benchmarking, the flexible io tester fio can be used. Raid 6, after raid 10, is probably the most common and useful raid level in use today. Linux software raid has native raid10 capability, and it exposes three possible layout for raid10style array. The main goals of using redundant arrays of inexpensive disks raid are to improve disk data performance and provide data redundancy. Linux hdparm command to test reading and caching disk performance again note that due to filesystems caching on file operations, you will always see high read rates. Jan 06, 2008 ive been working with server based raid controllers for a long time with pretty much all raid levels. Sep 26, 2017 ext4 was used throughout all the tests. This article covers raid level 0 and how to implement it on a linux system.
More details on configuring a software raid setup on your linux vm in azure can be found in the configuring software raid on linux document. The n2 layout is equivalent to the standard raid 10 arrangement, making the benchmark a clearer comparison. With the advent of hardware raid systems the battle was joined until the hardware array emerged victorious. So that your raid 10 is faster than your raid 5 at all means that your raid 5 wasnt performing up to snuff. Reading and writing performance issues can be helped with raid. Ive personally seen a software raid 1 beat an lsi hardware raid 1 that was using the same drives. Command to see what scheduler is being used for disks.
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