1,RAID 0RAID 0, most commonly known as striping, provides improved I\/O rates (in terms of IOPS) by striping the data across multiple drives, allowing the read and write operations to be shared amongst the drives inside the array.This level of RAID provides the best performance for both read and write operations, butprovides no redundancy or protection against data loss. In the event of a single disk failure in the array, all of the data is lost.
\none task A,have a+b, for raid0:risk 1:a,risk 2:b ,so:
\nn disks: n(read+write)<\/p>\n
2,RAID 1, most commonly known as mirroring, provides protection against the loss of
\ndata from a single disk by mirroring the writes to a second disk but doesn't provide added write performanceto the system, since the maximum throughput for the array is limited to the I\/O capacity
\nof a single disk
\none task A,have a+b, for raid1: write: risk 1:a+b,risk 2:a+b ,so:
\nn disks: (n read + n\/2 write)<\/p>\n
3,RAID 10
\nRAID 10, or RAID 1+0, is a nested RAID level known as a "striped pair of mirrors." It
\nprovides redundancy by first mirroring each disk, using RAID 1, and then striping those
\nmirrored disks, with RAID 0, to improve performance.
\none task A,have a+b, for raid10: write: risk 1:a,risk11:a, risk 2:b ,risk:22 b
\nso:
\nn disks: (n read + n\/2 write)<\/p>\n
4,RAID 01
\nRAID 01 or RAID 0+1, is a nested RAID level also known as "mirrored pairs of striped
\ndisks." In a RAID 0+1 configuration, the nested levels are the opposite of the RAID 1+0,
\nwith the disks first being striped in a RAID 0 and then mirrored using RAID 1. However,
\nthis type of configuration only allows for a single disk loss from one side of the array,
\nsince a single disk failure in a RAID 0 array causes that array to fail. A loss of a single disk
\nin both of the RAID 0 striped arrays would result in total data loss.<\/p>\n
5,RAID 5 (and 6)
\nRAID 5 is commonly known as "striping with parity;" the data is striped across multiples
\ndisks, as per RAID 0, but parity data is stored in order to provide protection from single
\ndisk failure. The minimum number of disks required for a RAID 5 array is three. The
\nparity blocks containing the parity data are staggered across the stripes inside the array
\nn disks: ((n-1) (read +write)<\/p>\n
Raid 0 –\u6bcf\u4e2a\u78c1\u76d8\u7684I\/O\u8ba1\u7b97= (\u8bfb+\u5199) \/\u78c1\u76d8\u4e2a\u6570<\/p>\n
\n\t\u3000\u3000Raid 1 –\u6bcf\u4e2a\u78c1\u76d8\u7684I\/O\u8ba1\u7b97= [\u8bfb+(2*\u5199)]\/2<\/p>\n
\n\t\u3000\u3000Raid 5 –\u6bcf\u4e2a\u78c1\u76d8\u7684I\/O\u8ba1\u7b97= [\u8bfb+(4*\u5199)]\/\u78c1\u76d8\u4e2a\u6570<\/p>\n
\n\t\u3000\u3000Raid 10 –\u6bcf\u4e2a\u78c1\u76d8\u7684I\/O\u8ba1\u7b97= [\u8bfb+(2*\u5199)]\/\u78c1\u76d8\u4e2a\u6570<\/p>\n
\t\u7531\u4e0a\u77e5\uff0craid5\u4e0eraid10\u6bd4\u8f83\uff0craid5\u5bf9\u5355\u5757\u78c1\u76d8\u7684I\/O\u8981\u6c42\u8f83\u9ad8\uff0c\u5e38\u91c7\u7528raid10
\n\t\u867d\u7136raid5\u5947\u5076\u6027\u662f\u5b9e\u73b0\u5bb9\u9519\u7684\u4e00\u79cd\u4e0d\u9519\u7684\u65b9\u5f0f\u3002\u4f46\u662f\u4ece\u78c1\u76d8\u5199\u5165\u6765\u8bf4\u4ee3\u4ef7\u9ad8\u6602\u3002\u4e5f\u5c31\u662f\u8bf4\u5bf9\u4e8e\u6bcf\u4e00\u4e2aIOP\u5199\u8bf7\u6c42\uff0cRAID5\u9700\u89814\u4e2aIOPS\u3002<\/p>\n
\n\t \u4e3a\u4ec0\u4e48\u9700\u8981\u8fd9\u4e48\u9ad8\u5199\u5165\u4ee3\u4ef7\u7684\u8fc7\u7a0b\u5982\u4e0b:<\/p>\n
\n\t \tLog files: \ttempdb:As a general rule, the tempdb database files should be physically separate from the user \t <\/p>\n http:\/\/blog.tianya.cn\/blogger\/post_show.asp?idWriter=0&Key=0&BlogID=854352&PostID=20759437<\/p>\n","protected":false},"excerpt":{"rendered":" 1,RAID 0RAID 0, most commonly known as striping, provid […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-2185","post","type-post","status-publish","format-standard","hentry","category-sql-server"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/posts\/2185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/comments?post=2185"}],"version-history":[{"count":0,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/posts\/2185\/revisions"}],"wp:attachment":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/media?parent=2185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/categories?post=2185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/tags?post=2185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n\t6,choose what?
\n\tData files:
\n\t 1,depends heavily on the read-to-write ratio for the .SQL Server tracks the I\/O usage of the database files for an instance and makes this information available in the sys.dm_io_virtual_
\n\tfile_stats Dynamic Management Function. While this information can be used
\n\tto determine if your overall workload is heavier for reads vs. writes.
\n\tFor a database that is primarily read-only, RAID 5 or RAID 6 can offer good read performance.
\n\t2,RAID 5 or 6 arrays are commonly used for data warehouses,<\/strong> or for storing data where write latency doesn't impact overall system performance.
\n\t3,For OLTP implementations of heavy-write databases, RAID 1+0 provides the best performance<\/strong><\/p>\n
\n\t Since the transaction log is written to sequentially, RAID 1 can be used in most situations<\/strong>.the transaction log for each database should be located on dedicated physical disks<\/p>\n
\n\tdata files and transaction log files, on a dedicated disk array. Since tempdb is a writeheavy
\n\tdatabase, RAID 1 or RAID 1+0 are usually the configurations best able to support
\n\tthe concurrent workload of tempdb.since tempdb is used for temporary storage only, Solid State Disks<\/strong> and even RamDisks can be used to significantly improve the I\/O characteristics of the tempdb database<\/p>\n