Differences

This shows you the differences between two versions of the page.

@@ Line 1: / Line 1: @@
+<markdown>
+# Backing Up
+## Date: Thu 29 Nov 2018
+## Create a new disk in VirtualBox
+Let's create a second hard drive in VirtualBox first.
+. Go to Settings
+. Click on Storage
+. Highlight **Controller: SATA**
+. Click on the Plus-Floppy icon
+. Click on **Add Hard Disk**
+. Click on **Create new disk**
+. Create a **VDI** disk (this is just like the initial install process)
+    - Feel free to name your disk and allocate a maximum size
+    - Since this will be used for backing up, the size of the disk should be
+      equal or larger than the size of the main disk
+## Prepare disk
+. Start your machine and log in
+. Check to see that your new drive exists:
+    - run `lsblk` or `fdisk -l | less` to find your drive
+    - should be located at `/dev/sdb`
+Now we need to partition the disk and make a file system. Recall that we need
+to use `parted` for this. However, this time when we run the `print` command in
+`parted`, we'll get a notification that we're missing a disk label. This is the
+same thing as a [partition table or partition map][1], and for our purposes,
+we'll use the *gpt* or [GUID Partition Table][2].
+After we use parted to create the disk label, we'll then exit out and from the
+root command prompt, we'll make the file system, and mount the *external* hard
+drive to the `/mnt` directory:
+```
+# parted /dev/sdb
+(parted) print
+...
+(parted) mklabel
+New disk label type? gpt
+(parted) print
+...
+(parted) mkpart
+Partition name? []? backup
+Filesystem type? [ext2]? ext4
+Start? 0%
+End? 100%
+(parted) print
+...
+(parted) quit
+# lsblk
+# mkfs.ext4 /dev/sdb1
+# mount /dev/sdb1 /mnt
+```
+*Note 1*: We can skip using `parted` and proceed to `mkfs.ext4` if we want to
+use the whole disk, but `parted` allows us to create multiple partitions on a
+storage device, which are useful with large disks. Remember that multiple
+partitions also allow us to have multiple file systems on a single physical
+device.
+*Note 2*: We can add the partition to `/etc/fstab` for auto mounting, but it's
+not entirely necessary for backup drives -- of course, it depends on the
+context. I avoid it here.
+## Backing up
+### Backup and sync
+There are many backup options, and the book does a nice job covering some of
+the big ones. Therefore, in this demo, I'll cover `rsync`, but I'd also
+encourage you to read this article on [`duplicity`][3].
+`rsync` is:
+```
+man -k rsync
+rsync (1)     - a fast, versatile, remote (and local) file-copying tool
+```
+See the **SYNOPSIS** in the `rsync` man page, but the basic syntax is:
+```
+$ rsync [OPTION...] SRC... [DST]
+```
+Let's use `rsync` to back up my `home/` directory to our new drive:
+```
+# mount /dev/sdb1 /mnt
+rsync -ahv --delete /home/sean /mnt
+```
+Where the following options mean:
+* -a, --archive
+    - archive mode
+* -h, --human-readable
+    - output numbers in a human-readable format
+* -v, --verbose
+    - increase verbosity
+* --delete
+    - delete extraneous files from dest dirs
+### Backup, sync, and exclude
+Let's say there are certain directories in the source location that we do not
+want to back up. To exclude those, we can create a file and list those sources
+in that file, and then tell `rsync` to skip them during the backup. E.g., let's
+say I have a directory (regular files work too) called **Documents/** and a
+file called **hello-world.txt** in my home directory, and I don't want those
+backed up in this process:
+```
+$ nano /home/sean/.exclude-rsync
+Documents/
+hello-world.txt
+$ rsync -ahv --delete --exclude-from '/home/sean/.exclude-rsync' /home/sean \
+  /mnt
+```
+### Remote backups
+We can backup over the internet using `ssh`. Let's backup a test
+**/home/sean/tmp** directory to a remote **tmp/** directory. We'll also play
+around with creating and removing files:
+```
+$ mkdir test ; cd test ; touch a.txt
+$ rsync -ahv . csbu225@sweb.uky.edu:/home/csbu225/tmp
+$ mv a.txt b.txt
+$ rsync -ahv . csbu225@sweb.uky.edu:/home/csbu225/tmp
+$ ssh sweb ls tmp/
+$ rsync -ahv --delete . csbu225@sweb.uky.edu:/home/csbu225/tmp
+$ ssh sweb ls tmp/
+```
+### Restore
+To restore, we just work in reverse since the SRC directory is now the backup
+location and the DST directory is now the restore location:
+```
+$ cd /mnt
+$ rsync -ahv --delete /mnt /home/sean
+```
+[1]:https://www.gnu.org/software/parted/manual/html_node/mklabel.html
+[2]:https://en.wikipedia.org/wiki/GUID_Partition_Table
+[3]:https://fedoramagazine.org/taking-smart-backups-duplicity/
+</markdown>

C. Sean Burns: Notebook

User Tools

Site Tools

Differences

Page Tools