While the first aspect tells us if the hard disk drive performance really increases with raid0, the second aspect will tell us if this increase in disk performance if any will be translated into. Raid 0, or disk striping, requires at least two disk drives and increases performance by. Raid 0 is bad because it doesnt improve seek time the crux of hd performance and its extremely unreliable. Shown below is the graph for raid6 using a 64kb chunk size. Raid 1 data is mirrored on each drive, improving read performance and reliability. Software raid how to optimize software raid on linux. In general, software raid offers very good performance and is relatively easy to maintain. Raid10 requires a minimum of 4 disks in theory, on linux mdadm can create a custom raid 10 array using two disks only, but this setup is generally avoided. The theoretical and real performance of raid 10 server. Using the smaller chunk size makes block output substantially faster for software raid but also more than halves the block input performance. Bite the bullet and invest in a good raid card and good drives to go with it. You can benchmark the performance difference between running a raid using the linux kernel software raid and a hardware raid card.
When they said that it is built on top of linux, they mean it. Mdadm is linux based software that allows you to use the operating system to create and handle raid arrays with ssds or normal hdds. The fallaway in hardware raid performance for smaller files is also present in the raid10 iozone write benchmark. The storage performance council spc, which develops benchmarks for products that range from disk and tape storage subsystems and storage network equipment to data backup and archiving software. Contains comprehensive benchmarking of linux ubuntu 7. Will if you have created a single raid partition and started to copy files from or to it speed will be duplicated if you are using 2 hdds for that raid partions, you will notice the difference in speed, but will not see the difference in the other partions. 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. Ive personally seen a software raid 1 beat an lsi hardware raid 1 that was using the same drives. The raid software is what is used to configure the desired raid level of features in an array. Raid 0 increases performance by allowing read and writes to be performed concurrently. How raid can give your hard drives ssdlike performance. If you want the best possible performance, give up on the idea of using software raid. A benchmark comparing chunk sizes from 4 to 1024 kib on various raid types 0, 5, 6, 10 was made in may 2010.
1248 587 935 486 375 1675 831 912 1207 441 987 783 636 203 377 105 1513 1435 1657 81 549 760 807 854 490 755 1171 1327 888 43 1278 839 287 1226 231 414 1200 849 337