Talk:Mdadm

Unnamed section

Keep it. This content is not a man page, but a description of the term/name. The newly added description of it's function will help people looking to find out why they might have it, or if it should be shelved on their system. It is a good thing.

(IMHO)Jrbeaman (talk) 03:43, 27 November 2007 (UTC)

Name

The original name was Mirror Disk when only mirroring on complete spindles was supported. As MD has increased in power it is now called Multiple Device to reflect that different RAID (and non-RAID) levels are supported on any block-structured device such as a disk, partition or USB stick. Martin of Sheffield (talk) 16:21, 19 May 2011 (UTC)

Re-vamping Quick Refererence

I'm working on cleaning up the quick reference, see My sandbox. Please leave any comments here or on My talk. Editing is not yet complete, I will announce it here when I am happy with the results. Martin of Sheffield (talk) 13:15, 26 May 2011 (UTC)

The first draft is now complete in my sandbox. Martin of Sheffield (talk) 17:11, 31 May 2011 (UTC)

Sandbox copy now inserted as live page. Martin of Sheffield (talk) 09:35, 7 June 2011 (UTC)

Increasing RAID5 Performance section is wrong

echo 16384 > /sys/block/md0/md/stripe_cache_size 
blockdev --setra 16384 /dev/md0

I tried this and it actually dropped my read speed from 212 MB/s to 192 MB/s

I scaled back the setra number to 4096: blockdev --setra 4096 /dev/md0;

and now my speed is restored.--71.194.190.179 (talk) 18:12, 2 August 2011 (UTC)

Would you care to work on this section? The section was originally added by 67.174.60.55 and since I can't easily test it I have left it alone. To be fair, did you note the comment: "This tip assumes sufficient RAM availability to the system. Insufficient RAM can lead to data loss/corruption"? You might need to check that there are no issues on your machine due to memory depletion. Martin of Sheffield (talk) 09:49, 3 August 2011 (UTC)

I have a system with raid 5 over 7*2TB disks and 8GB of ram that should be ok for testing right? The bad part is that initially i could not even make the setting, but i probably just have to un-mount the file system first. And second the test suggested with dd only tests liniair speed, not random access. --Robin den hertog (talk) 07:28, 19 September 2011 (UTC)

Absolutely none of this discussion has any bearing on an encyclopedia article, and this discussion page is not a filesystem tips forum.Dfeuer (talk) 01:43, 3 January 2012 (UTC)

Purge

This article was mostly how-to material, as was noted back in 2010. Nobody did anything about that, so I decided to be bold and just delete it all. If someone wants to move it to Wikibooks or Wikiversity, they're welcome to cut and paste from the page history.Dfeuer (talk) 01:52, 3 January 2012 (UTC)

I have now copied the original article to Wikiversity.Dfeuer (talk) 02:10, 3 January 2012 (UTC)

Dfeuer: Without going into too much detail of how I philosophize regarding what wikipedia is and is not, I would call a very big shenanigans on your extremely ill advised solo flight into reverting this article into a dumbed down product stub. Wikipedia is more than a collection of blog entries on available "things". The fact that it can include "Howto" like entries is one of the very big assets of an open encyclopedia. And to be fair, I'll counter any reply by asserting that I do not give two shitsome as to whether some policy or your own opinion says different. This was an awesome article before that demonstrated not only the great software that mdadm is, but also highlighted ---in detail--- its various abilities. Go right ahead and dumb this place down as well. As I said: I don't give one too many. And, I won't stop you. That's just the way the cookie crumbles in this day and age. Just people on solo flights, not giving a crap about what use a given thing maybe to others. Frankly, I am appalled. 91.96.231.235 (talk) 23:51, 7 January 2012 (UTC)

Excuse me for ranting on. But, I guess I need to explain why I'm not engaging in some stupid revert war with this dumbo, who obviously knows not a thing about the item at hand. It's because, I'd be reverted in turn, he'll whine about the "omg, your only an IP" thing and it'll just be another sob story on wikipedia. I know there is some excellent stuff on wikipedia. But, it's mostly the entries that are somewhat hidden from view as it were. How can wikipedia ever hope to actually "compete" with the likes of Britannica if not by departing from the classical idea of an "honorable" encyclopedia. No knowledge should be regarded too lowly or unworthy to include. I have always loved the way that you could get actual hands on info on this blog. However, I find it is being shoved down the pipe by control fanatics who think they incorporate the grant idea of what this is all about. It is a crying shame, because people like Dfeuer prevent me from seeing the worthy info others put on here. Geez, he's not even considering how well written this was. I absolutely cannot believe it. Wikipedia is slowly sucking up to something, and I don't know what it is yet at this point. 91.96.231.235 (talk) 00:05, 8 January 2012 (UTC)

The policy is pretty clear, the content of this article doesn't belong here. Moving it to a more appropriate wiki, like WP's sister site Wikibooks, and linking to that external entry is the correct option --Outlyer (talk) 16:20, 17 August 2012 (UTC)

Any progress on this? IMHO the whole "Quick Reference" part can go, maybe keep the "Mdmpd" section, if relevant. The "Known problems" section looks like more How-To material to me... RealLink (talk) 10:03, 7 November 2012 (UTC)

Hi, I just want to say, that I'm just a person who was looking for some info about mdadm and I found the section "Quick reference" in this article extremely useful! I might be wrong, but i suppose the Wikipedia team wants it to be useful. Right? I know that the knowledge is probably possible to find somewhere else, but... I don't know the other places and I know Wikipedia. So I found it convenient. Just saying. Regards. 80.254.148.99 (talk) 12:46, 26 February 2013 (UTC)

It's just my learned opinion that we should not give a flying fuck about what the policy says in this case and just leave this highly informative article the way it is. If must be, keep the warning banner on the top. I don't give a monkey's. Just leave the content here and all will be well. 91.96.27.179 (talk) 16:47, 16 March 2013 (UTC)

I agree with you, but keep in mind that if you have an archive of information you can organize it better. I don't like the "deleting all the stuff because for me are not good enough for a wikipedia article and nevertheless i don't care about the knowledge that i just deleted, i don't even look to move it elsewhere", that is a misbehavior or worse "acting dumb". But moving it elsewhere, maybe in a better container (look wikibook/wikiversity), helps only to improve the content so why not? Would someone be so kind to check any differences with the wikiversity article and put a link between this article and that one? Thanks! And anyway, be sure that is better to store the knowledge instead of losing it. Pier4r (talk) 15:18, 15 November 2013 (UTC)

It looks like Thumperward deleted the entire quick ref section in April without further discussion. While there is an automatic link to wikiversity where the content is replicated, then it was not immideatly obvious that that was the pace to go, so I have added a heading "Quick Reference" which explicitly points that out -- while that means that there are trippe references, then given the historical nature of this article and the number of time I have found this page useful **just for the quick reference** then I think having a extra link or two would be warranted. Alternatively moving the content back in regardless of the policy would be my next preferred action. Sorenriise (talk) 00:22, 24 September 2014 (UTC)

I've removed this. It doesn't pass the laugh test to assert that theoretically competent persons looking for said technical documentation should be so stupid as to not to be able to find the link to it in its standard position in the sidebox. Wikiversity's relatively low Google ranking is unfortunate, but it isn't our problem. Chris Cunningham (user:thumperward) (talk) 11:10, 24 September 2014 (UTC)

Reading the trails, I'm not able to find anyone who agree with your opinion. Until this article I was not aware of that there were anything called wikiversity in the first place, and the obscure link of that "it hold information" does not indicate that it is the lost information which is over there, or any other compelling reason to go and look there -- hence at minimum having a link stating that "Quick reference over there" would be rather nice given the controversial decision to delete the information from wikipedia. Sorenriise (talk) 08:13, 25 September 2014 (UTC)

Disagreement (especially based on non-arguments such as "it is useful" or "I am lazy") != "controversy" (another sadly all-too-common Wikipedia trope). But there are three people in this very comments thread that agreed with its removal other than myself, so it looks as if your difficulty in extracting present information from content doesn't just apply to articles. Chris Cunningham (user:thumperward) (talk) 12:32, 25 September 2014 (UTC)

Calling people lazy is probably against WP:CIV. My point is that question is not whether the documentation can be found elsewhere, which I agree that it can -- the official man page has all the information. I have been using mdadm and linux raid devices since 1999 but I still find the official documentation bewildering as it is so large and due to the number of options is hard to decode. The set of Quick Reference commands which are now on wikiversity covers over 99% of the daily use-cases and hence is very useful as a true "Quick reference" and it is not a question of being lazy. I have at no point intended that we should pull the entire Quick Reference back in the wikipedia article, and my edit which you rolled back was a descriptive link for the new location. The current widget just says "Wikiversity has additional information", which is a non obvious link when im looking for the quick reference. My question to you is, how do we make this information more obvious to find? Should I split the wikiversity article into something with a better name? Is there (should there) be a parameter to the wikiversity macro which better describes what kind of content lives over there? Could we put a better described link in one of the "See Also" or "Reference Section", and if so which section would be most appropriate to hold such link? Sorenriise (talk) 22:34, 26 September 2014 (UTC)

I've made the link text more verbose, as suggested. Chris Cunningham (user:thumperward) (talk) 09:09, 30 September 2014 (UTC)

Thanks for that. The edit you made, created a broken link -- I have fixed that edit an edit here and a redirect on wikiversity, so pls don't rollback to a state with broken links. 99.103.198.159 (talk) 15:14, 30 September 2014 (UTC)

Looking good! I'm glad that you've found the way to resurrect the usable content that has been deleted from this article. — Dsimic (talk | contribs) 07:19, 2 October 2014 (UTC)

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Correctness sum of error rate

The article states "In effect, the failure rate of the array of storage devices is equal to the sum of the failure rate of each storage device. " I'm unsure on the correctness of this information. On this page the https://en.wikipedia.org/wiki/Mean_time_between_failures, under the section "MTBF and MDT for networks of components" a different calculation is given. This should be the correct calculation:

${\text{mtbf}}(c_{1};c_{2})={\frac {1}{{\frac {1}{{\text{mtbf}}(c_{1})}}+{\frac {1}{{\text{mtbf}}(c_{2})}}}}={\frac {{\text{mtbf}}(c_{1})\times {\text{mtbf}}(c_{2})}{{\text{mtbf}}(c_{1})+{\text{mtbf}}(c_{2})}}\;,$

where $c_{1};c_{2}$ is the network in which the components are arranged in series. (taken from the MTFB page)

Perhaps, with "sum" the text was referring to such a formula, but in that case the text is ambiguous. — Preceding unsigned comment added by TTheCreator (talk • contribs) 17:57, 10 May 2020 (UTC)