While I’m not going to go into all of the options available (this is very well documented in the RAID wikipedia entry), I do feel that it is noteworthy to say that you should always opt for at least RAID 6 or even higher (we will be using Linux RAID10). That may be true, however despite these claims, server grade drives still have a higher level of S.M.A.R.T restrictions and QAing behind them (as can be observed by the fact that they are not released to the market as soon as the consumer drives are), so i still highly recommend that you fork out the extra $$$ for the upgrade. Some may say that there is no difference in fail rate between the two types. While there was no data loss, because the RAID did it’s job well and survived… moments like this shorten the life expectancy of the sysadmin, not to mention down time for the company for the server maintenance (something which may end up costing more then the higher grade drives). At least four consumer grade drives in the 3 servers I have setup like this (due to budget constraints) failed after about 1.5 ~ 1.8 years from the server’s initial launch day. Trust me, yours truly has tried this for you. Despite of their attractive price, consumer grade hard drives are not designed to be used in a 24/7 “on” type of a use. Now i know what your thinking, didn’t we say we are going to go on the cheap? and yes we did, but, this is exactly one of the places where doing so is reckless and should be avoided. The first step in avoiding a trap is knowing of it’s existence (Thufir Hawat from Dune).Ĭhoosing the disks is a vital step that should not be taken lightly, and you would be wise to capitalize on yours truly’s experience and heed this warning:ĭo NOT use “consumer grade” drives to create your array, use “server grade” drives!!!!!! RELATED: Which Type of RAID Should You Use For Your Servers? Choosing the disks that make the array Depending on the type of RAID you want to create you will need at least two disks on your system and in this guide we are using 6 drives.Doing so allowed me to use sda1 as part of the RAID array, so adjust accordingly to your setup. The Ubuntu system I used for writing this guide, was installed on a disk-on-key.You will see me use VIM as the editor program, this is just because I’m used to it… you may use any other editor that you’d like.This guide was written using Ubuntu server9.10 圆4, therefore it is assumed that you have a Debian based system to work with as well.It is assumed you know what RAID is and what it is used for.Patience young one, this is a long read.
#Open source raid monitor software
The Tom’s Hardware guide “ Tom’s goes RAID5” is an oldie but a goody exhaustive article about the subject, which I personally use as reference, however take the benchmarks with a grain of salt as it is talking about windows implementation of software RAID (as with everything else, i’m sure Linux is much better :P). As far as disk performance go, there is a penalty… however I have never encountered a bottleneck from the disk subsystem from the server to note how profound it is. With a software RAID setup your sacrificing some of the systems CPU performance in order to reduce total system cost, however with todays CPUs the overhead is relatively negligible (especially if your going to mainly dedicate this server to be a “file server”). The main disadvantages are basically performance and some reliability as such a card usually comes with it’s own RAM+CPU to perform the calculations required for the redundancy math, data caching for increased performance, and the optional backup battery that keeps unwritten operations in the cache until power has been restored in case of a power out.
The main advantage of such a thing is cost, as this dedicated card is an added premium to the base configuration of the system. Image by Filomena Scalise About software RAIDĪs the name implies, this is a RAID (Redundant Array of Inexpensive Disks) setup that is done completely in software instead of using a dedicated hardware card. With that said, going cheap/free does not mean “throwing caution to the wind”, and to that end, we will note points to be aware of, configurations that should be set in place in addition to using software RAID, to achieve the maximum price to reliability ratio.
0 kommentar(er)
