{"id":174,"date":"2015-06-22T17:46:11","date_gmt":"2015-06-22T17:46:11","guid":{"rendered":"http:\/\/www.balajibandi.com\/blog\/?p=174"},"modified":"2017-02-05T17:55:45","modified_gmt":"2017-02-05T17:55:45","slug":"using-a-linux-host-via-qemu-in-gns3","status":"publish","type":"post","link":"https:\/\/www.balajibandi.com\/?p=174","title":{"rendered":"Using a Linux host via qemu in GNS3"},"content":{"rendered":"
So, lately I’ve been studying for the CCNA exam, which is probably 15 years overdue. \u00a0Part of the exam is running commands on a router or switch. \u00a0Unless you happen to have access to a rack full of Cisco gear you can change at will you’ll need a simulator. \u00a0GNS3 is just that – a simulator that lets you set up virtual switches and routers and “connect” them virtually. \u00a0It works great!GNS3 also has a built-in QEMU module so you can add virtual hosts to your pretend network. \u00a0That means you can start a web server on one end and a client on the other and actually connect them. \u00a0Or whatever you want really.<\/p>\n

But you have enough to do without learning QEMU right? \u00a0So here’s a quick guide to integrating Damn Small Linux into GNS3. \u00a0I’m using Windows 7 64bit as my workstation.<\/p>\n

DSL – Damn Small Linux.<\/b>
\nI chose this distribution because it’s tiny, starts quicky and uses very little memory. \u00a0You can start up a DSL virtual instance in 128m of RAM. \u00a0Here are the tricks I used to get it working.<\/p>\n

Versions used.<\/b>
\nGNS3 0.7.4 – Ships with QEMU
\nDamn Small Linux – 4.4.10 32bit ISO<\/p>\n

First obtain the DSL ISO image. \u00a0I downloaded it and placed it directly into the GNS3 program folder in Windows 7, which is located in\u00a0C:\\Program Files (x86)\\GNS3<\/p>\n

Start a windows CMD prompt and CD to the GNS3 directory.<\/p>\n

C:\\Program Files (x86)\\GNS3<\/b><\/p>\n

Now create a QEMU virtual disk. \u00a0This will contain your DSL instance.<\/p>\n

C:\\>\u00a0qemu-img\u00a0create\u00a0dsl 1G<\/b><\/p>\n

This creates an 1GB “container”. \u00a0You can probably make it smaller, or bigger. \u00a0It can be grown dynamically anyway if you need more space.<\/p>\n

Now boot Damn Small Linux from QEMU in the command line.<\/p>\n

C:\\Program Files (x86)\\GNS3>\u00a0<\/b>qemu\u00a0-hda dsl -cdrom\u00a0dsl-4.4.10.iso\u00a0-m\u00a0256 -boot\u00a0d<\/tt><\/em>
\n
\n<\/tt><\/em>> -hda dsl: indicates the “dsl” partition you made will be in the “hda” physical partition.
\n> <\/i>a – cdrom dsl-4.4.10.iso: indicates that the ISO image will be used as your CDROM.
\n> -m 256: Use 256m of RAM
\n> -boot d : indicated D drive is the boot drive.<\/p>\n

DSL should now spin up. \u00a0Just follow the prompts. \u00a0Eventually the desktop will come up. \u00a0Right click on the desktop and navigate to Apps \/ Tools \/ Install to Hard Drive.<\/p>\n

A script will launch. \u00a0Enter these params at the prompts.<\/p>\n

Target partition: hda
\nSupport multii-user? \u00a0Sure, why not. \u00a0Enter ‘y’
\nUse ext3 filesystem? \u00a0y
\nLast chance? y<\/p>\n

It will warn you that hda is the entire drive and not a partition. \u00a0That’s OK, confirm it.<\/p>\n

Now DSL will install itself into your virtual disk. \u00a0Neat! \u00a0Wait awhile and DSL will ask you if you want a bootloader. \u00a0Confirm Yes and when prompted – chose LILO by entering ‘l’ (lowercase L).<\/b> \u00a0This is important, GRUB will not work.<\/p>\n

Eventually DSL will try to reboot. \u00a0It will fail, because it can only be launched by QEMU. \u00a0DSL doesn’t know it’s a virtual instance it thinks it’s on real hardware. \u00a0What it doesn’t know won’t hurt it.<\/p>\n

Now, your DSL should be fully installed. \u00a0Back in the DOS prompt you should be able to launch it with this command.<\/p>\n

C:\\Program Files (x86)\\GNS3>\u00a0<\/b>qemu\u00a0-hda dsl -m 256<\/tt><\/em>
\n
\n<\/tt><\/em>You can use any amount of RAM you want, I think 256 is safe though.
\n<\/i><\/p>\n

Now, let’s configure GNS3 to launch your desktops by itself.<\/p>\n

Launch GNS3 and go to Edit \/ Preferences \/ Qemu section. \u00a0Most of the info will be filled in for you.<\/p>\n

Click on the Qemu Host tab. \u00a0Create a new instance for DSL:<\/p>\n

Identifier name: Name it whatever, I called it “DSL-1”
\nBinary image: It took me a long time to figure this one out. \u00a0Where does Qemu store its virtual disks??? I finally found them after searching the hard drive. \u00a0Click the “…” button and browse to:
\nC:\\Users\\\\AppData\\Local\\VirtualStore\\Program Files (x86)\\GNS3\\<\/b> – your Qemu instances should be in here.
\nRAM: 256 (or whatever)
\nNumber of NICs: How many do you want? \u00a0They’re free! \u00a0I left it at 6.<\/p>\n

Pick the rest if it’s important to you, or leave it at defaults and hit Save. \u00a0Now, test your Qemu settings on the General Settings tab. \u00a0If everything is working, when you launch a Host then a DSL virtual desktop should automatically pop up!<\/p>\n

\"\"<\/a><\/div>\n<\/div>\n
<\/div>\n","protected":false},"excerpt":{"rendered":"

So, lately I’ve been studying for the CCNA exam, which is probably 15 years overdue. \u00a0Part of the exam is running commands on a router or switch. \u00a0Unless you happen to have access to a rack full of Cisco gear you can change at will you’ll need a simulator. \u00a0GNS3 is just that – a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,7],"tags":[],"class_list":["post-174","post","type-post","status-publish","format-standard","hentry","category-gns","category-linux"],"_links":{"self":[{"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=\/wp\/v2\/posts\/174","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=174"}],"version-history":[{"count":3,"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=\/wp\/v2\/posts\/174\/revisions"}],"predecessor-version":[{"id":520,"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=\/wp\/v2\/posts\/174\/revisions\/520"}],"wp:attachment":[{"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.balajibandi.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}