Configure Multipath In Redhat Enterprise Linux Server 7 | Native Maltipathing | RHEL 7 |CentOS7

[Music] welcome in this video I am going to demonstrate and going to show you how to configure multipath in Turner Enterprise Linux server seven so what is multiple the first question so multipath is nothing but we are using a more than one path so it is self-explanatory saying that we are using more than one path it could be two three like that so what is the reason behind it because for example in most scenario in IT environment production servers they use fiber channel switch and they use CIN storage area network so from them from them we allocate learn and from server end we use them and we scan them and we formatted them as LVM or whatever we are using it so now whenever we are using those learn from storage area network through fibre channel switch if there is a one part in whether in is in fabric for channel switch or in your hospice adapter which is called SBA is failed then we should be able to have a redundant and there is a redundant part through which we should be able to access the same drive in case of port failure or in case of cable is faulty or in case of three or five a channel switch is faulty right so to avoid this those we use multipathing and in Red Hat Enterprise Linux and not only other Enterprise Linux all Nix based operating system we have a native multipathing so we need to just install them and enable it so that is how what I'm going to do in this system and I'm going to show you but currently since I am using a virtual environment and I do not have a fiber channel switch environment I'm going to configure or allocate the land from a scuzzy target server to this system in client system and I'm going to configure the multipath right so to do that what I need is I need to go to my I square the target server and I need to configure that so let me just show you what that one so those are the region so let me just go to the server and here currently if I do I PA I have only one interface so this is the interface and this is running this IP so and I I showed you in my previous video you know I scuzzy target and I see the initiator video how to I look at the LUN and if you have not watched that video peace go through that video to understand better so now I have allocated to learn from my eyes because you target to this system and if I run this command LS blk I have to be able to see this is the tool on one GB and there is another it base which is the size of 2zv and this two discs are coming from one single IP so the IP is this one so in case this interface is cause down and for some reason I'm unable to access this interface then what will happen in my client system this to learn what I am accessing will inaccessible and I won't be able to access this to learn to avoid this we need to have some kind of fault tolerance right so what I'm going to do is I'm going to allocate another one or two interface in this target server and again I'm going to discover this to learn from the client end and I will configure a multi path in this client system and let's see how it goes so first thing what I have to do is I need to power of this system because it is better to come up with all drivers when the system is coming up I think the you rules will not create if I do an online so let me just power it off and let me just go to my virtual machine here is the virtual machine and I have power rod power of my system and the system is running fine so let me just locate two additional 800 interface so let me just add like this network next finis and I will aide and another interface fitness okay so I have added and at the two interface currently I have all three interface and I just bought on my system and it will take it will not take much time because there is nothing running but I scuzzy target here so there should not be any issues to boot the system up so let's wait for probably one minute and my system came up let me just go to petition here and let's take a restart session and login with the root then so now if I just do a IPA I can be able to see there are two more interface which is located here but there is no IP on them so what I'm going to do is I'm just going to go inside this location sorry in this is not the one and let's do CD to this location and I see there is a file only for the first interface the other interface is not created so let me just create an interface like this probably 60 is 37 and one is 38 and let me just modify them so it would be same interface name is a little different here 36 name is 36 so it should be 37 here I just need to make that change is 37 here and I need to save this and now I need to make a change on the other interface so the other interface is 38 and let me save it and let me do a up for both the interface and let's see if there is any IP it is allocated okay it says so meter in 37 let me just do it for the other one I have up slowly IP a and I do not see IP on them so let me just double check 37 38 and let me just - sorry it is rhel7 so I need to run something called systemctl restart Network and looks like some issue in my interface so let me see the you devrel m dot or eighties rules this your depth and the rules there is a file and there is no interface created here so what I have to do is let me just double-check everything again it is 37 37 and this one is 38 38 but still I'm unable to any well my IP so let's do one thing just restart my system one more time and let's see if it comes up or not my system are my system is up and now I will be able to login and let's try to troubleshoot it why I'm unable to do it even though I have change those settings but it is not working for some reason so let me just go back to this location here and these are the two files if I do IPA okay so it probably means I need to create a device name something like this one and this one so that is why it is not able to start the IP or enabled IP let me just do something like this one I have CFC and the first interface is this one then and second interface is this one then so now this 37 and 38 I won't need it so let me just remove generic 37 38 and now if I just go inside this file I need to change the name here for to this one The Meters to VI I have CFC you know 33 and let me go to name here and change the device as well and I think the dw/bi D is also not required let me just hesitate for now so 92 East and let me do it for this one VI and let me just copy this portion and change the name here and has the ear ad so because it is for the post interface and let me just start the service and hopefully this time it should work restart network and let's hope everything goes fine and I do not see any error here and let me just do a IP a and now it is looks fine so I can able to see the first interface it has AP 31 33 and I should have one more 32 so 31 32 33 so 3 IP I have it so now next thing if I go to my client system and if I discover the land here again and let me run this command again I forgot the command 4 so I get initiator let me just get this file here again and let me just discover it like this and the IP is 31 for the first IP second is 32 and third is 33 so I can able to discover it so now next is to login and let me just login and IP is 31 sorry it is test here not broad and I can able to log in without any issue it seems there is something about the multiple thing that can be ignored since it is successful so I am able to discover it so now the LAN which I'm using here PB s minus a minus o plus de velasco sighs they're coming in coming for three paths so it's device now is coming from three paths okay so now I'm going to configure a DM multipathing so this is a built-in package which come with none had DVD so let me just do a device mapper multipath so this is the package and it is already installed so I don't need to install it so next step is to start the service start multipath multiply the service so I have started the service and now the next step I need to do is multi-part hippin ll to check whether I can able to see my this so looks like my disk is not able to see because there is a file called multiple dot con which needs to be available under slash c TC and that file is not that whether I can copy the file from this location it is a simple file in this location or you can create one so to create that we have one command called empath config and Botcon - - we just have to specify user underscore friendly names and when I have run this command with one option we have either friendly names and I said no it has created one fine under CTC and now I'd be able to see there is a file so my file is there now if I do I can multi path ll it is still there but it's saying the look module is not loaded so what I have to do is I just have to do a multi path sorry mod proof to load the module and module name is multi path DM dear multipath is not found it seems let me just start restore the service again and let's see if that helps okay so now when I restart the service the module has started already and if I just check now wait what was the issue with my module name let me just take the module named multi path and it seems that in our agency when it is something else so so DM underscore multipath so this is a little slight change in rhel7 early acid well earlier it was DM - multipath and now it called DM underscore multipath so not an issue so now when I run this command I can able to see both the lens so this length are having three paths now you can see the first it is coming from this path and another one is thirty-four and third one is thirty-five so by default you don't need to do anything if you just install it by default it will create a file like what I have created and you can specify your options inside this file so if I just go to file multipath conf you can able to see this is the option which I have selected while creating this file user-friendly no and fine multi path it is saying yes so what I'm going to do now I'm just going to comment this here which means disabling this and I'm going to enable a default option so this will going to help me why because there are more options like in default you can see polling interval in every 10 second each path will going to check the other path whether it is alive or not so this is what it is and I'm just going to enable this here and the next thing is what method I'm going to use whether it is a round-robin or fault tolerance so random wind is a better method so I'm just going with the default and multi pass grouping ID serial and other options you can see those option and their work in multiple dot-com manual probably I can show you that one so here the user friendly names if I make it as user friendly names equal to yes let me show you what going to what it will going to happen and there would be okay so let me just save it and do a systemctl restart multipath D and now notice here you you see the line like this and now if I do multi path ll now you can see here it is saying empath be empath a so this is because I have said user friendly name equal to yes so this could causing confusion because whenever every time you are restarting your service or restore your server this may change that is why it is preferable to not to use the definite name equal to yes instead we need to use no and also I can see there is some issue in line 30 number so 31 let me go to line 31 and here looks like it seems fine but I need to close this again here probably okay so now let me do one thing first thing what I'm going to do I'm just going to make this is no here so that it doesn't show like multi path a or multi path empath a or a path B and the other important thing is you can blacklist your device for example you do not want it to see any days which is a lock till dis probably starting with SD and you do not want to see those output in multi-part - I'll L so you can blacklist this and also you don't want it to see something starting with name or you do not want to see your floppy device information so those you can enable it here so you can just blacklist just enable this option I'm just enabling all this and apart from that you can also use aliases so example I can show you what is the use of aliases so let me just save this fine and restart the multi-part service again and let's do a multi Vatican ll and okay so it says it duplicate keyword let me okay so actually the problem is here so there is a need to has this here and if I use this blacklist this portion this portion should be inside this default person because now I am seeing two different portion and that is why I am getting that error and apart from that if you wanted to use your device some aliases so probably I wanted to say this disc on this land I am going to use for data and I am going to use this man for my Oracle so you might be having a number of plants assigned to your system and you do not want it to confuse and however that you probably wanted to specify some alias name so for that also what you can do you can go to this section your default section wherever you are specifying your LUN and then you just need to specify something like WWI D and let me just copy this here sorry and this is going to be my LAN you and double-double ID and let me just go back here and I have to specify my none information here let me know this the first one let me copied it here and the aliases I'm just going to say the data this is for my data VG and Elias portion probably and it's to be a bed here and enable this one and this should be this would be one more curly braket I need to close it here that is why I'm getting that error and let me just restart this multipath service and let's see what its source this time so so it is giving the same thing so that means the setting which I have made is not correct so probably I have to do it in a little different way so what I'm going to do is I'm just going to comment all this line and I'll just come down here in multipath portion since I'm using Elias and let me just enable everything here and for aliases I can use this portion right so let me just enable it and this one I don't need this to portion I don't need so let me just comment it come in this to portion and here I can specify mind an ID I'll just go back here and copy this the new ID and name I will do data and same thing and you would be able to close it here like this and let's let's just do for one run first and let's see whether this is working or not okay so this time it is working and now you can see this one is belongs to data group all that IVD and here for this one it is not there so that's got to there's some issue in line 37 so okay so here blacklist is enabled let me just disable this two line here and if I start the service and do a multipath ll I do not see any error so it is coming clean and now probably I need to add an alias for this line let me go to that portion and copy the dildo lady here and I have to specify like this small tea pot can we break it open and enter my double dip di D is this one and now my alias name is for hora probably for Oracle me I'm going to use and I just need to remove this close it here and I need to close one more time yeah so now it looks fine so let me see whether how it went fine or not and everything seems to be fine now I can see there is an aura and now you can see data so both are available and I can see these are coming in thrillin so now what is a use like I'd earlier discuss for example now my this part or this part is failed or this HP a power assume this is a name which is coming from an HB m so the first is BA 33000 this is down and it is not accessible so what we can do probably we can do it for that last one because I logged into a system with this IP so probably I will do it for the last IP so what I'm going to do is I'm just going to this system here and IP a and I can see the 3 interface here 1 2 3 so I'm going to make it down here so let me just make it down down and it is disconnected so now if I do IPA I can see it is up 31 is up 33 is up 32 is done and let's see what happened in my system so here I can able to see if I do a multiple fan ll I can able to see the third on this IP it is saying fall fell t fall B so that means that path which is I'm accessing this learn through this path this path is failed so now I can see here the failed of failed ever but still I have two paths active this one and this one through the through this two paths I'm accessing Milan and I can able to access it not an issue so that is that is the main region see that's it I think you don't yeah I believe I have able to clear what I have trying to show you here for regarding multi path so there is a region and let me just make that interface again up and let's see I would be able to see that or not and now my interface is up all the interfaces of 31 32 33 and let me go to the system and if I do a multiple different ll okay so it is still saying failed so not an issue probably what we can do is we can just rescan it reload the multi path let me just reload it again or you don't need to restart it every time for any changes additional changes you can do I reload so now I probably able to see okay so 40 40 again it is saying 40 probably because I have to login again for dead IP so let me just and that command for 33 I believe I make it down so what was I this one I have conflict this is for 32 okay so let me just do it for 32 again and now I think I should be able to find but it is still saying failed so I think I need to restart my service for multi path so easily for private channel environment you don't need to restart it if you just do three Lord it walks so normally you don't need to restart the service but here it is saying faulty fail for this one still and it is still I'm unable to see that so let me just scan it for everything 31 32 33 so there was must be an issue with this is cozy if I restore the service but still it is giving me an issue here probably let me just stop the service and trying if that helps multi-part and then it is still saying my multi-part information okay so it's still confused right now because it should not sure so let me just do a logout for all this three AP and now again login for thirty-one thirty-two so for thirty-two it is taking a little time I hope this IP is up 32 is up here David's minus F okay so seems like some issue in my IP 32 that is why I'm still saying that is failed so anyway meanwhile the point was about the multipathing configuration so that I have showed you so that works but only thing didn't work here about the IP 32 it is still saying failed so anyway so currently I have logged into two IP one is 31 and 33 so 32 has some issues that is why I am unable to see and if I run multiple - ll I can able to see there are two paths now so this is the first one and okay so again it came so now I can see all three paths so there is some issue it means because it is some time it says failed and some time it says faulty so in SK see in real time scenario production environment we should we should not be used as Cathy so this is for this and I want to show you how to configure multipathing that is why I'm showing you so currently not an issue I can able to see all the three but for this two lengths so those are the three lengths three paths and those are the two lengths I also showed you how to make an alias for them so this is what about multi path there is nothing much about it if you still wanted to understand about what are those options are and what are those option means then you just need to go to multi-part manual file and you can understand from there for this polling interval what it does and other information like multi path directory and priority or for path grouping those information you can get it from this manual so basically there is nothing much in multi path so we use for fault tolerance if something goes wrong in one pot one pot so another pot is still available and still configured in multi pot so we would be able to access it so that is the main region so I believe I am amiable to I am able to discuss or I am able to tell you or whatever regarding multi path and it makes sense to you I believe if not then please let me know and please write write them in need of comment section and let me know and feel free to ask me if any have any doubts okay so for now this is it I need that is whatever I was supposed to discuss in this video so please subscribe my channel okay and also please hit like if you like this video campaign okay so Singh thank you so much for watching this video have a good day and see you next time

Channel: Tune To Linux

Views: 37,447

Keywords: how to configure multipath in linux, how to configure multipath in redhat linux, linux multipathing, linux multipath tutorial, redhat linux multipath, device mapper multipathing, Linux multipath, configure multipath in centos, configure multipath in rhel6, configure multipath in rhel7, how to configure multipath linux, redhat linux multipath configuration, native linux multipath, device mapper multipath rhel 6, device mapper multipath rhel 7

Id: -aGmEB-iYX0

Length: 39min 12sec (2352 seconds)

Published: Sun Jul 02 2017