jbod

. (It is recommended that you do not delete the created vhd file, which will be used in subsequent operations) 650) This. width = 650; "src =" http://s3.51cto.com/wyfs02/M02/30/89/wKiom1OoMOmiDg-tAAQRdzThBA8077.jpg "Title =" image46.png "alt =" wKiom1OoMOmiDg-tAAQRdzThBA8077.jpg "/> At the end of this operation, Mr. Zhang, who is good at learning and flexible using the new technology, created a virtual volume with multiple physical disks of different capacities. In this way, the free disk can b

RaidPerformance of disks 1.定位 2.旋转 3.命令队列 4.数据库传输HBA: Host-based adapterRaid:redundent array of inexpensive Disks inexpensive disk arrayIndependent Standalone disk arrayLevel: Only used to identify the different ways of disk composition, can not replace data backup raid0：提高读写性能，没有容错能力。至少需要两块磁盘 100% raid1：至少需要两块硬盘，镜像，硬件容错能力，读性能提升，写性能下降 50% raid4：至少需要三块硬盘，允许一块盘出错，读写性能提升，（n-1）/n raid5: 至少需要三块硬盘，允许一块盘出错，读写性能提升，（n-1）/n raid6: 至少需要四块磁盘，允许两块盘出错。读写性能提升，（n-2）/n raid10：至少需要四块磁盘。允许不同组内个各坏一块盘，读写性能提升

and volume of storage is large, but each disk is prone to bad, so the probability of his damage goes up.In order to prevent change, just a copy of the data two copies, this technology is mirrored mirror. Another technique is the cyclic redundancy check code (RAID4), which is not used to store data on the disk, but the check code on this disk, when one of the bad, the use of checksums and other disk data to recover the data on the broken disk, so that the disk utilization is good, But a two-piec

. Disk utilization is (n-2)/nIn addition, there is a disk combination mechanism JOBD technologyJBOD: is to stack multiple disks into a large logical disk, and then use the second disk when the first disk is out of capacity.Thus JBOD has the following characteristics:1. Requires at least 2 disks to be combined into JBOD2. Data is stored sequentially from the first disk, so read and write performance is not improved3, no redundancy mechanism, when one o

At least 4 bucks. 5+0: Performance: Read and write promotion Redundancy capability: Available Space utilization: (n-2)/n At least 6 bucks. JBOD: To combine multiple small discs into a single market Performance: None Redundancy capability: None Space utilization: 100% At least 2 bucks.Logical raid: /dev/md# /dev/md1 /dev/md2 /dev/md3Md:Mdadm: Make any block device raid Modal Commands:

a powerful hardware engine also built-in memory controller, Allows al-7121a memory to have a more flexible range of choices from 1GB to 4GB capacity. The RAID 5 and RAID 6 hardware acceleration performance is also significantly enhanced. Supported by RAID capabilities, AL-7121A's support for RAID is quite comprehensive, supporting not only the common raid levels of 0, 1, 3, 5,10, 6, 60,nraid, but also the current very popular JBOD to ensure that dif

storage (JBOD). ********************************************************************************************************* Asmlib and Udev Both Asmlib and Udev solved the problem of fixed device names. In Linux, the order in which devices are detected and enumerated is not fixed. This is not the same as in Solaris, for example, unless a disk is physically moved in the array, the device name (for example, C0T0D1P1) does not change. Reconfiguration of

performance degradation, read performance improvementRedundancy capability: AvailableSpace utilization: 50%At least 2 pieces of diskHow the RAID5 works:The RAID5 uses an array of independent accesses, and the checksum information is distributed evenly across the disks of the disk.Performance: Improved read and write performanceRedundancy capability: AvailableSpace utilization: (n-1)/nAt least 3 pieces of diskHow the RAID10 works:RAID10 organizes the array in a way that mirrors first and then st