WEBVTT 00:00.180 --> 00:05.940 There are two types of people on earth those who have lost data and those who do not backup. 00:05.940 --> 00:11.860 So in this episode I want to talk about backups in today's highly automated cloud based world. 00:11.880 --> 00:17.040 Backing up seems almost trivial I don't know about you but with my high end Android phone I can pretty 00:17.040 --> 00:22.410 much break it in half by a new phone and everything pretty much magically comes back to life. 00:22.410 --> 00:28.470 So backing up is important but from an enterprise level in particular when we're talking about I.T. 00:28.470 --> 00:33.570 security there are certain issues you're going to see on the exam and I want to delve into these a little 00:33.570 --> 00:34.050 bit. 00:34.050 --> 00:37.640 So let's go ahead and get started first by talking about backup methods. 00:37.740 --> 00:41.360 Here I have a little computer and I want to back this computer up. 00:41.430 --> 00:44.740 Now we can back this up to an external hard drive. 00:44.820 --> 00:47.040 We could back it up to a tape. 00:47.130 --> 00:49.470 We could even back it up to the cloud today. 00:49.470 --> 00:55.080 But the problem is is that when we do a backup The only thing we can do is backup everything. 00:55.080 --> 00:58.870 Now if we do a backup of everything better known as a full backup. 00:59.040 --> 01:04.330 That's absolutely fantastic and it is an important part of any backup methodology however. 01:04.410 --> 01:11.250 And let's assume we backup every day at the end of the day as we go from Monday Tuesday Wednesday Thursday 01:11.250 --> 01:12.110 and Friday. 01:12.120 --> 01:16.520 That means every day we are spending X amount of time doing a full backup. 01:16.740 --> 01:19.380 And do we want to keep making full backups every day. 01:19.380 --> 01:20.320 The answer is No. 01:20.340 --> 01:21.920 It takes a long time. 01:21.960 --> 01:23.470 It puts in a lot of overhead. 01:23.490 --> 01:30.510 So if we can avoid that let's go ahead and avoid that and we can we can do this because all file systems 01:30.510 --> 01:35.380 have features built into them that give us clues as to when files have been changed. 01:35.550 --> 01:43.280 Here for example is a Linux system and I'm typing a command called stat on a file called cleverly file. 01:43.380 --> 01:48.660 And if we look at this file we'll see that it has a modified date and we could use that information 01:48.660 --> 01:51.720 to be able to determine from our last backup. 01:51.720 --> 01:54.770 Has this been modified or not in a Windows system here. 01:54.780 --> 01:57.270 I'm running Windows on top of NTFS. 01:57.270 --> 02:03.930 We have what's known as the archive attribute the archive attribute is turned on when ever a file is 02:03.930 --> 02:05.820 created or changed. 02:05.820 --> 02:10.370 So as we look at these three files here you'll see the first two you see that letter A. 02:10.560 --> 02:12.480 That shows that they've been changed. 02:12.480 --> 02:15.710 The third one is that the bottom has not been changed. 02:15.720 --> 02:18.220 Now using that we can do some cool things. 02:18.240 --> 02:20.230 We have two different options here. 02:20.250 --> 02:26.430 The first one is called a differential backup a differential backup basically means to backup all changes 02:26.430 --> 02:28.590 from the last full backup. 02:28.590 --> 02:35.730 The alternative is an incremental backup the incremental backup only backup changes from the last backup 02:35.820 --> 02:37.220 of any type. 02:37.230 --> 02:41.030 Let me show you how that works starting with a differential backup. 02:41.040 --> 02:45.990 So here we have Monday Tuesday Wednesday Thursday Friday at the end of the day on Monday we make a full 02:45.990 --> 02:47.070 backup. 02:47.070 --> 02:54.690 Now on the end of the day on Tuesday by reading this file information we can only make backup of the 02:54.690 --> 02:57.990 files that have changed on that one day. 02:57.990 --> 03:03.360 Now on the next day we make backups of all the files that have changed remember differential means since 03:03.360 --> 03:04.670 the last full backup. 03:04.950 --> 03:11.760 So this backup is going to be all the changes on Tuesday and Wednesday on the end of the day on Thursday 03:11.760 --> 03:13.450 we do another differential backup. 03:13.470 --> 03:19.320 And in this case we have all the changes of Tuesday through Thursday and then on Friday. 03:19.320 --> 03:22.890 Everything from Tuesday through Friday. 03:22.890 --> 03:28.770 The nice part about a differential backup is that you only need two backups to be able to restore. 03:28.950 --> 03:34.950 So let's say it's Friday and we've lost everything in that case what we do is we grab our full backup 03:34.950 --> 03:41.910 from Monday and we grab our backup on Thursday which reflects everything that's happened since that 03:41.910 --> 03:43.040 last backup. 03:43.140 --> 03:50.160 And with these two backups we can completely restore the system differential backups are fantastic because 03:50.220 --> 03:56.080 if you're using a weekly backup format as many many people do you're only going to have two backups 03:56.090 --> 04:02.940 that you worry about at any given moment your full backup and then whatever differential backup is important 04:02.940 --> 04:05.410 for you for whatever you want to do your restore from. 04:05.580 --> 04:07.340 So differentials fantastic. 04:07.350 --> 04:09.900 You have a very small number of backup sets. 04:10.050 --> 04:15.670 However backup sets get bigger and bigger and bigger over the course of your backup period. 04:15.840 --> 04:17.840 So there's an alternative to this. 04:17.850 --> 04:19.620 The alternative is incremental. 04:19.620 --> 04:21.610 Let me show you how that works. 04:21.660 --> 04:25.300 So let's start off once again by having our full backup on Monday. 04:25.310 --> 04:28.180 Now keep in mind we're going to be doing an incremental backup. 04:28.260 --> 04:34.440 So in this case what we're going to do is we're going to at the end of the day on Tuesday make a backup 04:34.680 --> 04:38.280 of only that which is changed on Tuesday. 04:38.430 --> 04:43.340 Now when Wednesday comes along we'll make another backup a separate backup of everything that changes 04:43.350 --> 04:47.250 on Wednesday and the same with Thursday and Friday. 04:47.250 --> 04:53.250 Now let's imagine that Friday comes along and we've had a corruption and we need to restore using an 04:53.250 --> 04:54.390 incremental backup. 04:54.390 --> 05:00.400 I'm going to need my full backup plus everything from Monday plus everything from Tuesday everything 05:00.440 --> 05:06.360 Wednesday plus everything from Thursday in order to create a complete backup. 05:06.380 --> 05:11.180 So generally when we're talking about backups I don't care what your methodology is I don't care what 05:11.180 --> 05:16.730 you're backing up to but you're almost always going to be in a situation where you're using full backups 05:17.000 --> 05:21.160 combined with either incremental or differential depending on your needs. 05:21.170 --> 05:23.030 The answer's easy differential. 05:23.060 --> 05:28.880 There are less back ups sets but they get bigger incremental more backup sets but smaller. 05:28.880 --> 05:29.510 All right. 05:29.510 --> 05:34.420 Now there is one other type of backup that comes into play and that is snapshots. 05:34.430 --> 05:40.910 Now we see snapshots typically under virtual machines and they are an absolute perfect way of making 05:40.910 --> 05:43.540 a copy of something that's happened in the past. 05:43.550 --> 05:48.710 The only downside to these types of things is that stamp shots are traditionally not stored on separate 05:48.710 --> 05:49.510 media. 05:49.520 --> 05:53.680 There's nothing against doing that here at total seminars when we make important snapshots. 05:53.810 --> 05:59.130 We add them to our backup sets and they're part of our overall backup process. 05:59.960 --> 06:02.690 So you've got all of these backups. 06:02.750 --> 06:04.070 So what are you going to do with them. 06:04.070 --> 06:07.160 So first of all you have to decide on your media. 06:07.160 --> 06:11.130 Number one if you go old school here you're talking about local backups. 06:11.180 --> 06:18.010 Now these could be tapes these could be external hard drives and they could be a separate backup that's 06:18.010 --> 06:21.390 stored locally local backups have one big benefit. 06:21.530 --> 06:24.130 Nearby in case anything messes up. 06:24.380 --> 06:30.740 So you can imagine the alternative which is an offsite backup is not nearly as convenient. 06:30.740 --> 06:32.510 However that's one big benefit. 06:32.600 --> 06:39.400 And that is if you catch fire or explode or something terrible happens you have a remote backup. 06:39.410 --> 06:45.500 What we'll see in a lot of situations is that we will keep local backups but then we also have a second 06:45.830 --> 06:48.550 offsite backup just in case. 06:48.560 --> 06:54.650 Now if you really want to be cool the fun way to do things is using cloud backup cloud backups work 06:54.650 --> 07:01.330 beautifully However they have one big downside and that is they take up a tremendous amount of time 07:01.330 --> 07:03.440 to get the initial backups going. 07:03.490 --> 07:07.450 So that first full backup that you're going to do can take quite a while. 07:07.450 --> 07:14.620 However once that's made what you'll see with most cloud backup providers is they do pretty much a continuous 07:14.920 --> 07:16.900 ongoing incremental backup. 07:16.900 --> 07:23.200 So once it's made it can be a very very powerful tool for keeping your data intact.