473,735 Members | 1,975 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Commonly used hardware RAID

18 New Member
*A RAID distributes data across several physical disks which look to the operating system and the user like a single disk. Several different arrangements are possible. We assume here that all the disks are of the same capacity, as is usual. A number of standard schemes have evolved which are referred to as levels. There were three RAID levels below used most commonly, but many more variations have evolved, notably several nested levels (such as RAID 0+1, RAID 1+0, RAID 5+0, RAID 5+0, etc.) and many non-standard levels (Most of these non-standard RAID levels are proprietary).
RAID 0
Striped Disk Array without Fault Tolerance: Provides improved performance and additional storage but no fault tolerance. Any disk failure destroys the array, which becomes more likely with more disks in the array. A single disk failure destroys the entire array because when data is written to a RAID 0 drive, the data is broken into fragments. The number of fragments is dictated by the number of disks in the array. The fragments are written to their respective disks simultaneously on the same sector. This allows smaller sections of the entire chunk of data to be read off the drive in parallel, giving this type of arrangement huge bandwidth. RAID 0 does not implement error checking so any error is unrecoverable. More disks in the array mean higher bandwidth, but greater risk of data loss.

RAID 1
Mirroring and Duplexing: Provides fault tolerance from disk errors and failure of all but one of the drives. Increased read performance occurs when using a multi-threaded operating system that supports split seeks, very small performance reduction when writing. Array continues to operate so long as at least one drive is functioning. Using RAID 1 with a separate controller for each disk is sometimes called duplexing.

RAID 5
Block Interleaved Distributed Parity: Distributed parity requires all drives but one to be present to operate; drive failure requires replacement, but the array is not destroyed by a single drive failure. Upon drive failure, any subsequent reads can be calculated from the distributed parity such that the drive failure is masked from the end user. The array will have data loss in the event of a second drive failure and is vulnerable until the data that was on the failed drive is rebuilt onto a replacement drive.
Sep 27 '10 #1
0 3561

Sign in to post your reply or Sign up for a free account.

Similar topics

2
1988
by: peter | last post by:
I've got a table which is used for storing votes, each row has a field with a reference to the user who's been voted for and i'd like to simply get the user ref with the most votes,or if tied, return both of them. I cant use subqueries as it's a mysql 4.0 server, any ideas on how i could do it (without retrieving all the nominees then doing select count(*) for all of them then sorting them externaly). thanks, peter
3
3463
by: fabio de francesco | last post by:
Hello, I have a couple of years of experience with C++. I started studying C++ syntax, then I read the B.Stroustrup's book, and eventually I went through the N.Josuttis' book on how to program with the C++ Standard Library. I am not a professional programmer however I would like to gain more knowledge of the language to get what could be considered the skills you'd expect from a professional developer ( I also know Unix
3
2005
by: Rich | last post by:
This is what one of the tables looks like - they are all similar and there are about 60 different tables: CREATE TABLE SalesData1( smalldatetime TimeStamp, varchar(8) CustomerID, numeric S1, numeric S2, numeric S3, numeric S4,
1
1237
by: Myk Quayce | last post by:
I'm writing a website using Notepad and ASP.NET and C#, and I'm trying to determine the best way of grouping commonly-used methods so they can be accessed by many .aspx pages. Any help would be greatly appreciated. TIA -- Myk Quayce
1
2556
by: serge | last post by:
I have a database that is around 2 to 4 GB. If I were to estimate some numbers like 4x growth or even 10x, the database size could reach 40GB. The new server will be running SQL Server 2005. I am not sure which configuration option to take. I've gathered some information from different places: Configuration #1: OS - Raid1 2x36GB
110
10613
by: alf | last post by:
Hi, is it possible that due to OS crash or mysql itself crash or some e.g. SCSI failure to lose all the data stored in the table (let's say million of 1KB rows). In other words what is the worst case scenario for MyISAM backend? Also is it possible to not to lose data but get them corrupted?
2
1547
by: Bit Byte | last post by:
Coming from a pure C/C++ background - recently started looking at C# for a project. The absence of header files in C# has thrown me "a bit of a curve". I want to modularise my code and put all the commonly used data types etc into a single compilation unit (library). How may I do this in C# - any examples would be useful - tx
1
1301
by: Andras Kovacs | last post by:
We use Raid 0+1 on all of our partitions except the one for TEMP. TEMP is running on a 200GB Raid 0 partition. I have spare disks to replace bad ones. I can bring back the system online within 10 minutes. We had a Raid 5 once here but I replaced it with Raid 0+1.
3
2310
tharden3
by: tharden3 | last post by:
What is the Progamming Language most commonly used to make big name games like COD4? Is it java? Would you use different ones for different types of games?
3
6462
by: jduhler | last post by:
Is there a way in SQL Server T-SQL to store commonly used SQL statements in a function, stored proc, or system variable? That way if that code ever changes I can change it in one place. If I use the code below in 100 different SQL statements... can I stored it somewhere and just call it from another SQL statement? For example, I want to call this very simplified statement 100 times from different stored procs::
0
9466
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...
0
9327
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth. The Art of Business Website Design Your website is...
1
9253
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
0
9201
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
0
6049
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
0
4564
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
0
4823
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
2
2740
muto222
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.
3
2190
bsmnconsultancy
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.