The calculator supports over the 10 major types of RAID setups. Various types of data units are supported for input, and while the cost is indicated in U. These can help you decide if the selected configuration is right for your particular case - be it for a server or a workstation. RAID stands for Redundant Array of Independent Disks, originally Redundant Array of Inexpensive Disks is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units.
The purposes is to provide data redundancy, performance improvement, or in certain cases: both.
Calculating filesystem stride_size and stripe_width for best performance under RAID
The term was coined in a paper by Patterson at. The particular configuration depends on the required level of performance and redundancy.
Each RAID level provides a particular balance across several variables: reliability, availability, performance, and capacity. The techniques to achieve that are: mirroringin which identical data is copied onto more than one drive; stripingwhich partitions each drive's storage space into units ranging from a sector up to several mb; parity - in which information is striped across each drive, allowing the RAID to continue working even if one drive were to fail.
Parity uses the XOR operation to allow information to be restored in case of a drive failure. Check the graphs below the levels table for visuals.
RAID levels greater than RAID 0 provide protection against unrecoverable sector read errors, as well as against failures of whole physical drives. You can use the above images to better understand the intputs and outputs of the RAID calculator.
In order to calculate the capacity of a disk array using our RAID capacity calculator, you need to know the peculiarities of each configuration, as some parts of it will limit the usable capacity of the array, like mirroring and parity.
Then, you need to know the number and size of the remaining disks and multiply them together. It is that simple, and it's even easier using our calculator.
This is the cost to have advantages like fault tolerance and high availability. This free RAID calculator will greatly assist you in this task.
In our RAID calculator you can select between four types of storage units: classic binary terabytes and gigabytes and SI terabytes and gigabytes. In order to differentiate between the two, the International System of Units SI made the horrible decision to start using existing terminology to refer to something else. Thus the terabyte TB became GB, instead of So, they needed a name for the GB terabyte, so they chose "tibibyte" with a symbol "TiB".
The story is the same with gigabyte and gibibytes GiB. Make sure to account for that insanity while planning your RAID. In our RAID calculator we support all four. RAID is no replacement for backup. Even though some RAID levels provide data redundancy, that doesn't mean it should be used as backup of your critical files. While a RAID protects you against drive failure, it does not protect you against errors human or otherwisefile corruption, malicious actors or RAID controller failure.Question: How Do You Resize a RAID 5 Array
None of those risks are accounted for in a simple RAID calculator. If you'd like to cite this online calculator resource and information as provided on the page, you can use the following citation: Georgiev G.
Calculators Converters Randomizers Articles Search. RAID Type. Drive Capacity. Drive Cost. Drives per RAID.What stripe size should I use? What cluster size should I format the drive to? The stripe size is the amount of user data in a RAID group stripe. This does not include drives used for parity or mirroring. The stripe is measured in KB. It is calculated by multiplying the number of stripe disks by the stripe element size. That would be a good cluster size to use.
You'll waste a little space on smaller files, but probably not enough to matter. In the Perc, use a segment size that matches, if possible I think it supports 64KB segments.
So you may want to choose that. Assuming you use 64KB stripe element size for KB stripe widthit wants to update just one of the stripe elements. So in RAID-6, that means first read 6 stripe elements one from each diskthen update one of the 64KB elements, then recalculate the parity, then write 3 of the 6 stripe elements the updated one and the two parity. I think this is called the read-modify-write cycle, and it's a performance killer, but that's the price you pay for parity.
So, ideally, your filesystem block size aka NTFS cluster size should be the same as your stripe width, or a multiple of it. But in practice, the performance difference is minimal except for worst case scenarios of heavy write loads of small files. If you have the time, try it both ways. Then benchmark copying over a few 5GB files. Since this is a large streaming write task, the performance will probably be the same.
Lots of information It sounds like you guys agree on using a 64kb NTFS cluster size, so that sounds good. It sounds like you guys are suggesting 64kb but almost everything I've read says to use kb for large files. Should I just compromise and go for kb? This is fairly confusing stuff, heh. It is only necessary to read the data segment and the parity segment s. The old data is then removed from the parity, and the new data added into it. This means that a RAID-5 single segment or partial segment write will require reads depending on what's in the cache and 2 writes.
Super User is a question and answer site for computer enthusiasts and power users. It only takes a minute to sign up. I initially set the stripe size to 1M since I will be storing large files much larger than 1MB. However, seeing the statistics made me reconsider my choice. I won't be using that for writing, leaving only the internal cache of the controller Adaptec Z. There were zero K or 1M reads. With writes, K is most common, K taking second place. The question: Will changing the stripe size to K or K or lower speed up the array considering the statistics?
Would that slow down the rebuild of the array? From your own data it should already be rather obvious to chose the most used chunk size. From the data you presented I would go for K assuming more reads than writes. How this turns out on your real world performance however is another story and depends heavily on the the type of load.
With very flat queues the difference will probably not be huge. Both of these clearly state that if you know which size your application s mostly use which seems the case with the given statistics you should go for these. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Recommended RAID5 stripe size? Ask Question.
Asked 5 years, 10 months ago. Active 5 years, 10 months ago. Viewed 17k times. Still, I would like to get the best performance from this array.Read this thread for more information.
Hello There, Guest! Login Register. Login Username: Password: Lost Password? Remember me. Thread Modes. The current volume stripe size is 64KB. Would re-striping the array at a smaller stripe size help this? What is the best procedure for that?
I assume that means the volume stripe size is 64KB. In video editing, normally a larger stripe size is better. Does that make sense? There is no way to change this setting. We are considering a couple enhancements in a future version of SoftRAID that would give your organizing tasks better performance, but we cannot pre-announce the kinds of features we have in mind. SSD"s would be much faster, but not cost effective.
There is no way to change this setting We are considering a couple enhancements in a future version of SoftRAID that would give your organizing tasks better performance.
However my case shows that is not always true, and 16 KB was a good choice. The uncertainty is if those little files fall out of the SSHD cache it wouldn't be any better. Real SSD's would have a dramatic impact. Hybrid, I share your skepticism. Plus, there is little known of the lifespan on hybrid drives, or their failure rates over time.
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What stripe size should I use for RAID-6?
Threaded Mode. Lost Password? Find Reply.Before talking about stripe size, it is important to mention the term stripe width, which equals the number of drives in a RAID array: for example, five drives equal a stripe width of five. Obviously, this value only changes if you alter the number of drives used in a RAID array; the more you add, the faster your RAID array will be, until you hit a controller or system interface bottleneck. Be careful here: stripe size does not represent the storage capacity of an entire stripe set spanning over all used drives.
A stripe set consists of all individual stripes as a whole, each of them having the selected stripe size. A stripe is the smallest chunk of data within a RAID array that can be addressed. People often also refer to this as granularity or block size. It can be compared to the blocks logical block addressing - LBA on conventional hard drives. Typical options are 16, 32, 64 and kB, but many professional RAID controllers also offer smaller stripe sizes, and some even support sizes as large as kB.
In fact, this feature is often overrated, as the performance changes are marginal on a typical gaming or office PC. However, it can be important for servers, though differences will still only be noticeable between very small and very large stripes with certain applications. If you want to create a RAID array for quick access to small files, small stripe sizes are favorable, to keep the waste of storage capacity small, and to provide high throughput thanks to a high level of data distribution across many drives.
File servers for photos, audio and video should, however, be operated with larger stripe sizes, as this helps to maximize sequential read performance. In the end, the best solution is to experiment with various options: try both a small and a large stripe size and collect performance data for it. Current page: Stripe Size Discussion. Stripe Size Discussion Before talking about stripe size, it is important to mention the term stripe width, which equals the number of drives in a RAID array: for example, five drives equal a stripe width of five.
In general, your stripe size choice has an impact on several factors: Performance Conventional hard drives deliver their best transfer performance when they read or write sequentially, repositioning the heads as little as possible. From this standpoint, it makes the most sense to select the largest stripe size available, especially if your hard drives are good at providing high throughput.
However, this only works if the files stored or read are at least as large as an entire stripe. If you will end of storing millions of text files, Word documents, small spreadsheets or similar small files, small stripe sizes will help to distribute all files across multiple drives to keep throughput high. Capacity Used The stripe size also defines the amount of storage capacity that will at least be occupied on a RAID partition when you write a file.
For example, if you selected a 64 kB stripe size and you store a 2 kB text file, this file will occupy 64 kB.
Obviously, the stripe size defines the minimum amount of data that a RAID controller will distribute files across its hard drives, in my example, 64 kB. See all comments 5. I've found conflicting opinions re stripe size, so I did my own tests though I don't have precision measuring tools like you guys.
My raid 0 is for gaming only, so all I cared about was loading time. So I used a stopwatch to measure the difference in loading times on Left 4 Dead when using 64kb and kb stripe size. The results for me were almost identical kb was faster by. That being the case, I erred on the side of kb in order to reduce the potential for write amplification I'm using 3x ocz vertex 2's.
What's remarkable is that, despite using the stopwatch to measure times manually, the results were always either identical, or separated by intervals of.I need help with deciding what stripe size to use for a RAID 5 setup. This is what I am trying to do. I will be using Veritas Backup Exec When going through the RAID 5 setup, the default size is 64kb but I have read that the larger the size the better the performance.
My stripe size choices are 4,8,16,64,, and KB. I just do not know enough about this to make an intelligent decision. The larger the size, the better the performance BUT the worse the utilization. So it is a trade off that you have to decide upon. Then like Scott says " crank it way up".
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It's fairly conservative but it will give you a nice large storage space which is typically what you are going for when you choose RAID 5. It also depends what you are storing. Lots of text files, keep it small. Storing nothing but VM images, crank it way up. The files will be created by Backup Exec and will come in 2 sizes. If the files really don't go smaller than 4GB I would totally go for the largest stripe size possible.
Ya, crank it up. Just like in any typical storage server scenario. Because like in my situation here at work you just never know what people are going to be throwing on there I see your poorly hidden file full of Mp3's you and your friends are dumping to I'm turning my back because I Hopefully you got the answer you were looking for?
RAID Scaling Charts, Part 3: 4-128 kB Stripes Compared
Any BA's or HP's to hand out? Brand Representative for StarWind. It also depends on how smart file system on top of a RAID is. To continue this discussion, please ask a new question. Get answers from your peers along with millions of IT pros who visit Spiceworks.This makes sense when you are running either on hardware or software raid under linux.
These two parameters could be supplied to mkfs. The biggest performance gain you can achieve on a raid array is to make sure you format the volume aligned to your raid stripe size. This is referred to as the stride. By setting up the file system in such a way that the writes match the raid layout, you avoid overlap calculations and adjustments on the file system, and make it easier for the system to write out to the disk.
The net result is that your system is able to write things faster, and you get better performance. I will try to explain it simple, at least in a way that I was able to understand this quick. Here are the MOST mistakes when calculating Stripe width, because of non-accurate calculating the number of data bearing disks. Now that we know our NODD Number of data-bearing diskswe can proceed with calculating the stripe width :.
I have a RAID 10 array with three active raid disks and zero spares. The layout is n2. Just confirming since NODD is not an integer.
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Save my name, email, and website in this browser for the next time I comment. Skip to content Table of Contents What is stride size and stripe width? How to calculate accurate stride size and stripe width?
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