Update and improve Emergency backup restore v4 page

- Update formatting and style to be consistent with the rest of the docs
- Improve language
- Clarify instructions
- Improve organization
This commit is contained in:
Andrew David Wong 2022-11-23 17:34:08 -08:00
parent e5c8e3d392
commit 9eb7926ffe
No known key found for this signature in database
GPG Key ID: 8CE137352A019A17

@ -12,13 +12,17 @@ title: Emergency backup recovery (v4)
This page describes how to perform an emergency restore of a backup created on
Qubes R4.X (which uses backup format version 4).
The Qubes backup system has been designed with emergency disaster recovery in
mind. No special Qubes-specific tools are required to access data backed up by
Qubes. In the event a Qubes system is unavailable, you can access your data on
any GNU/Linux system with the following procedure.
The Qubes backup system is designed with emergency disaster recovery in mind. No
special Qubes-specific tools are required to access data backed up by Qubes. In
the event a Qubes system is unavailable, you can access your data on any
GNU/Linux system by following the instructions on this page.
Required `scrypt` Utility
-------------------------
**Important:** You may wish to store a copy of these instructions with your
Qubes backups. All Qubes documentation, including this page, is available in
plain text format in the the [qubes-doc](https://github.com/QubesOS/qubes-doc)
Git repository.
## Required `scrypt` utility
In Qubes 4.X, backups are encrypted and integrity-protected with
[scrypt](https://www.tarsnap.com/scrypt.html). You will need a copy of this
@ -34,8 +38,8 @@ easier scripting, which means you'll need to enter the passphrase for each file
separately, instead of using `echo ... | scrypt`.
Here are instructions for obtaining a compiled `scrypt` binary. This example
uses an RPM-based system (Fedora), but the same general procedure should work
on any GNU/Linux system.
uses an RPM-based system (Fedora), but the same general procedure should work on
any GNU/Linux system.
1. If you're not on Qubes 4.X, [import and authenticate the Release 4 Signing
Key](/security/verifying-signatures/#how-to-import-and-authenticate-release-signing-keys).
@ -46,7 +50,7 @@ on any GNU/Linux system.
[user@restore ~]$ dnf download scrypt
or, if that doesn't work:
Or, if that doesn't work:
[user@restore ~]$ curl -O https://yum.qubes-os.org/r4.0/current/vm/fc28/rpm/scrypt-1.2.1-1.fc28.x86_64.rpm
@ -66,17 +70,19 @@ on any GNU/Linux system.
[user@restore ~]$ rpmdev-extract scrypt-*.rpm
6. (Optional) Create an alias for the new binary.
[user@restore ~]$ alias scrypt="scrypt-*/usr/bin/scrypt"
Emergency Recovery Instructions
-------------------------------
## Emergency recovery instructions
**Note:** In the following example, the backup file is both *encrypted* and
*compressed*.
1. Untar the main backup file.
1. (Optional) If you're working with binaries that you saved with your backup,
such as `scrypt` or `bzip2`, you can make things easier by aliasing those
binaries now, e.g.,
[user@restore ~]$ alias scrypt="/home/user/scrypt-*"
[user@restore ~]$ alias bzip2="/home/user/bzip2-*"
2. Untar the main backup file.
[user@restore ~]$ tar -i -xvf qubes-backup-2015-06-05T123456
backup-header
@ -90,32 +96,15 @@ Emergency Recovery Instructions
vm1/whitelisted-appmenus.list.000.enc
dom0-home/dom0user.000.enc
**To extract only specific VMs:** Each VM in the backup file has its path
listed in `qubes.xml.000.enc`. Decrypt it. (In this example, the password is
`password`.)
[user@restore ~]$ cat backup-header | grep backup-id
backup-id=20190128T123456-1234
[user@restore ~]$ scrypt dec -P qubes.xml.000.enc qubes.xml.000
Please enter passphrase: 20190128T123456-1234!qubes.xml.000!password
[user@restore ~]$ tar -i -xvf qubes.xml.000
Now that you have the decrypted `qubes.xml.000` file, search for the
`backup-path` property inside of it. With the `backup-path`, extract only
the files necessary for your VM (`vmX`).
[user@restore ~]$ tar -i -xvf qubes-backup-2015-06-05T123456 \
backup-header backup-header.hmac vmX/
2. Set the backup passphrase environment variable. While this isn't strictly
required, it will be handy later and will avoid saving the passphrase in
the shell's history.
3. Set the backup passphrase environment variable. While this isn't strictly
required, it will be handy later and will avoid saving the passphrase in the
shell's history.
[user@restore ~]$ read -r backup_pass
3. Verify the integrity of `backup-header`. For compatibility reasons,
`backup-header.hmac` is an encrypted *and integrity protected*
version of `backup-header`.
4. Verify the integrity of `backup-header`. For compatibility reasons,
`backup-header.hmac` is an encrypted *and integrity protected* version of
`backup-header`.
[user@restore ~]$ set +H
[user@restore ~]$ echo "backup-header!$backup_pass" |\
@ -123,28 +112,31 @@ Emergency Recovery Instructions
diff -qs backup-header backup-header.verified
Files backup-header and backup-header.verified are identical
**Note:** If this command fails, it may be that the backup was tampered
with or is in a different format. In the latter case, look inside
`backup-header` at the `version` field. If it contains a value other than
`version=4`, go to the instructions for that format version:
**Note:** If this command fails, it may be that the backup was tampered with
or is in a different format. In the latter case, look inside `backup-header`
at the `version` field. If it contains a value other than `version=4`, go to
the instructions for that format version:
- [Emergency Backup Recovery without Qubes (v2)](/doc/backup-emergency-restore-v2/)
- [Emergency Backup Recovery without Qubes (v3)](/doc/backup-emergency-restore-v3/)
4. Read `backup-header`:
5. Read `backup-header`.
[user@restore ~]$ cat backup-header
version=4
encrypted=True
compressed=True
compression-filter=gzip
backup_id=20161020T123455-1234
hmac-algorithm=scrypt
backup-id=20161020T123455-1234
5. Set `backup_id` to the value in the last line of `backup-header`:
6. Set `backup_id` to the value in the last line of `backup-header`. (Note that
there is a hyphen in `backup-id` in the file, whereas there is an underscore
in `backup_id` in the variable you're setting.)
[user@restore ~]$ backup_id=20161020T123455-1234
6. Verify the integrity of your data, decrypt, decompress, and extract
`private.img`:
7. Choose a qube whose data you wish to restore. Verify the data's integrity,
decrypt it, decompress it, and extract it.
[user@restore ~]$ find vm1 -name 'private.img.*.enc' | sort -V | while read f_enc; do \
f_dec=${f_enc%.enc}; \
@ -157,24 +149,17 @@ Emergency Recovery Instructions
**Note:** If your backup was compressed with a program other than `gzip`,
you must substitute the correct compression program in the command above.
This information is contained in `backup-header` (see step 4). For example,
if your backup is compressed with `bzip2`, use `bzip2 -d` instead in the
command above.
This information is contained in `backup-header` (see step 5). For example,
if your backup is compressed with `bzip2`, use `bzip2 -d` instead of `gzip
-d` in the command above.
7. Mount `private.img` and access your data.
8. Enter the decrypted directory, mount `private.img`, and access your data.
[user@restore ~]$ cd vm1/
[user@restore vm1]$ sudo mkdir /mnt/img
[user@restore vm1]$ sudo mount -o loop vm1/private.img /mnt/img/
[user@restore vm1]$ cat /mnt/img/home/user/your_data.txt
This data has been successfully recovered!
8. Success! If you wish to recover data from more than one VM in your backup,
simply repeat steps 6 and 7 for each additional VM.
**Note:** You may wish to store a copy of these instructions with your
Qubes backups in the event that you fail to recall the above procedure
while this web page is inaccessible. All Qubes documentation, including
this page, is available in plain text format in the following Git
repository:
https://github.com/QubesOS/qubes-doc.git
Success! If you wish to recover data from more than one qube in your backup,
simply repeat steps 7 and 8 for each additional qube.