1 00:00:00,000 --> 00:00:14,160 Hey guys and welcome back. 2 00:00:14,160 --> 00:00:19,559 So now what I want to do is just have a few more words on file system recovery. 3 00:00:19,559 --> 00:00:23,600 Now like I say, when you're dealing with file system recovery, you can be dealing with things 4 00:00:23,600 --> 00:00:30,880 such as corrupt file systems and a common cause of a corrupted file system is when a 5 00:00:30,880 --> 00:00:33,800 system is inappropriately shut down. 6 00:00:33,800 --> 00:00:34,800 So what do I mean? 7 00:00:34,800 --> 00:00:39,640 That would be like someone pulling the power out of the system or a power outage. 8 00:00:39,640 --> 00:00:43,600 This type of thing could lead to such corruption of the file system. 9 00:00:43,600 --> 00:00:48,320 So when such a thing happens, we want to be aware of some of the tools that we have available 10 00:00:48,320 --> 00:00:52,760 to us to help us out and resolve these issues. 11 00:00:52,759 --> 00:00:57,399 The command I want to highlight here is the FSCK command. 12 00:00:57,399 --> 00:00:59,920 This is the file system check command. 13 00:00:59,920 --> 00:01:02,519 And it really is quite easy to use this command. 14 00:01:02,519 --> 00:01:10,000 All you would ultimately do is say FSCK and then specify the partition you want to check. 15 00:01:10,000 --> 00:01:13,640 So I would say dev sda1 for example. 16 00:01:13,640 --> 00:01:20,000 And this will actually give us detailed information about what exactly is wrong with the partition 17 00:01:20,000 --> 00:01:21,159 in this case. 18 00:01:21,159 --> 00:01:26,760 And once it identifies a particular problem, it will then ask you, do you want to fix this 19 00:01:26,760 --> 00:01:27,760 problem? 20 00:01:27,760 --> 00:01:30,159 To which you want to reply yes. 21 00:01:30,159 --> 00:01:34,960 Now you can continually just keep entering yes to all the problems. 22 00:01:34,960 --> 00:01:35,960 Do you want to fix this? 23 00:01:35,960 --> 00:01:36,960 Do you want to fix this? 24 00:01:36,960 --> 00:01:37,960 So on and so forth. 25 00:01:37,960 --> 00:01:40,519 But you can imagine this is quite tiresome. 26 00:01:40,519 --> 00:01:45,760 Instead a good way to run the FSCK utility is with the dash y flag. 27 00:01:45,760 --> 00:01:51,320 What this is going to do is going to preempt any such prompts and just answer yes to every 28 00:01:51,320 --> 00:01:52,920 time we get a prompt. 29 00:01:52,920 --> 00:01:58,280 If you have a lot of issues, FSCK can just run through those problems and attempt to 30 00:01:58,280 --> 00:02:00,640 fix each one as they go through. 31 00:02:00,640 --> 00:02:04,000 Now one point of note here, and this is very important. 32 00:02:04,000 --> 00:02:08,879 We do not want to run the FSCK utility on a live system. 33 00:02:08,879 --> 00:02:15,719 That means if you happen to have a partition working and mounted, do not run this utility 34 00:02:15,719 --> 00:02:17,439 in fact, let me just quickly show you. 35 00:02:17,439 --> 00:02:24,280 So if I say the command LSBLK, we can actually see the root file system is mounted on SDA5. 36 00:02:24,280 --> 00:02:25,800 So this is mounted. 37 00:02:25,800 --> 00:02:32,000 If I did FSCK DEV SDA5 and hit enter, notice it gives me the warning. 38 00:02:32,000 --> 00:02:33,800 The file system is mounted. 39 00:02:33,800 --> 00:02:35,840 If you continue, you will cause severe damage. 40 00:02:35,840 --> 00:02:41,479 So we want to say N for no to make sure we do not run this command on a mounted file 41 00:02:41,479 --> 00:02:42,479 system. 42 00:02:42,479 --> 00:02:48,079 That would mean you may have to use commands such as the U mount command to unmount a particular 43 00:02:48,079 --> 00:02:49,079 file system. 44 00:02:49,079 --> 00:02:54,359 If you do suspect that it does have issues and needs to be fixed with FSCK, this command, 45 00:02:54,359 --> 00:03:00,319 which we actually went over in the LPIC1 examination can help you unmount a partition safely. 46 00:03:00,319 --> 00:03:04,679 And then you can run the FSCK check to fix any particular problems. 47 00:03:04,679 --> 00:03:09,239 Okay, those are some of the main commands that we can use to fix these types of problems. 48 00:03:09,240 --> 00:03:12,320 I hope this has been informative for you and I'd like to thank you for viewing.