BackupPC 配置

數據備份 Overview This page covers installing and configuring BackupPC java script:window.open(this.src);" onload="return imgzoom(this,550)">. I've been using BackupPC since early 2004 and have been pretty happy with 數據備份

Overview

This page covers installing and configuring BackupPC. I've been using BackupPC since early 2004 and have been pretty happy with it.

Overview

This page covers installing and configuring BackupPC. I've been using BackupPC since early 2004 and have been pretty happy with it.

Preparation

Backups will be stored under /var/lib/backuppc.If you want to have that correspond to a specific partition or diskit's easiest to do it before installing BackupPC. I created an LVMgroup/volume mounted at that location just for BackupPC data.

Installation

BackupPC requires a version of Apache to beinstalled. (Other web servers may also work, but you will be on yourown.) If you don't have Apache installed then Apache 1.3 will beinstalled for you. If you want a different version of Apache theninstall that before installing BackupPC.

apt-get install backuppc libfile-rsyncp-perl

The installation creates a backuppc user. In order to receive emails sent to that aclearcase/" target="_blank" >ccount consider creating a .forward in ~backuppc (which is /var/lib/backuppc).

Configuring Apache

If Apache just got freshly installed, consider updating /var/www/index.html.

The installation process creates a backuppc system account and web login. The password for the weblogin should be changed with htpasswd /etc/backuppc/htpasswd backuppc. The password for the system account is already secure and doesn't need changing.

The BackupPC web interface is now accessible at http://hostname/backuppc.

Configuring BackupPC

The main config file is /etc/backuppc/config.pl.Very little needs to be changed in this file! Most settings that seemlike that might need changing (e.g. backup method) are often bestconfigured on a per-client basis in separate files. I changed thefollowing:

$Conf = 1;

Changed to $Conf = [1, 0, 1]; so as to keep a full backup that was approximately one month old in addition to the current one.

$Conf = 7;

This settingspecifies for how many backups in a row a machine has be available tobe considered an "always-on" machine. I reduced it to 2. I occasionally(but rarely) turn my machine off at night and don't want one night'soutage to cause 7 days of mid-day instead of night-time backups.

$Conf

I extend the Blackout to be all hours of every day of the week except for 2:00am to 8:00am.

$Conf = [
    {
       hourBegin =>  8,
       hourEnd   =>  2,
       weekDays  => [1, 2, 3, 4, 5, 6, 7],
    },
];

That's it!

Specifying Clients

First add each machine to be backed up to /etc/backuppc/hosts. All my entries look like this:

calvin      0       backuppc

Now create a machinename.pl file for each machine that is to be backed up. A generic config file for a Linux box looks like this:

$Conf = 'rsync';
$Conf = ['/sys', '/proc', '/cdrom', '/dvd', '/floppy'];

As a general rule, don't use trailing slashes when specifying directories to exclude.

Mac OS X

A good set of excludes for Macs are

$Conf = ['.Trash', '/Trash', '/automount', '/Network', '/private/var/automount', '/private/var/run', '/private/var/vm', '/private/var/tmp', '/private/tmp', 'Caches', 'CachedMessages'];

Also, if using tar on Mac OS X (which you probably won't, see below) you need to inform BackupPC that the binary is now in the usual /bin/tar location:

$Conf = '/usr/bin/tar';

Mac OS presents a problem: Many apps (e.g. Quark, Quicken) store important data in resource forks. But the versions of tar and rsync that ship with Mac OS X only support single-stream files (this may change with Mac OS X 10.4 Tiger).

Aside from ignoring resource forks there are two basic ways to deal with them. One is to use a $Conf (seebelow) to make single-stream copies of important files containingresource forks by using BinHex or something similar. A better approachis to make either tar or rsync resource-fork aware. Such a resource-fork aware version would simply map dual-stream files into two single-stream files.

The steps to back resource forks up using tar are:

1. Install Helios xtar on the Mac(s) to be backed up.
2. If you're using BackupPC prior to 2.1.1 then on the BackupPC server, in /usr/share/backuppc/bin, apply BackupPC_tarExtract.diff.xtar_support with the commands

   mv BackupPC_tarExtract BackupPC_tarExtract.orig
   patch -o BackupPC_tarExtract BackupPC_tarExtract.orig BackupPC_tarExtract.diff
   chmod 755 BackupPC_tarExtract

   This patch was written by Craig Barratt himself.
3. In the client config file include the following line:

   $Conf = '/usr/bin/xtar';

Currently (2005-01) rsync is not an option. Andrew Reynhout has created a resource-fork aware rsync. However the Perl rsync emulator in BackupPC does not (yet) work with it. To install the new rsync just place it in /usr/bin, rename the existing rsync (e.g. to rsync_Apple) and make a symlink named rsync to the new version. Fix up the permissions and you're set.

marshmallow:/usr/bin root# ls -alF | grep rsy
lrwxr-xr-x    1 root  wheel        23 15 Aug 22:56 rsync@ -> rsync-2.6.2+hfsmode-1.1
-rwxr-xr-x    1 root  wheel    625696 15 Aug 22:54 rsync-2.6.2+hfsmode-1.1*
-rwxr-xr-x    1 root  wheel    211860  9 Aug 16:08 rsync_Apple*

Windows

Windows is tricky since you're unlikely to find an SSH server running and rsync or tarbinaries handy. The best solution is to install rsyncd on your Windowsmachines. You can get a simple Windows rsyncd installer from theBackupPC site. See the client setup manual page for more information. The config file for the machine will look like this:

$Conf = "rsyncd";
$Conf = "BackupPC";
$Conf = "******";
$Conf  = "cDrive";

$Conf = ['/winnt/tmp', '/pagefile.sys', '/hiberfil.sys', 'Temporary Internet Files/', '*Cache/', 'Thumbs.db', 'IconCache.db', '~*', 'desktop.ini', 'NTUSER.DAT', 'USRCLASS.DAT', '/RECYCLER', 'Virtual Machines/'];

Alternatively smbclient can be used to access a standard Windows share. Simply replace the rsync config lines with these:

$Conf = 'smb';
$Conf = 'C$';
$Conf = 'BackupPC';
$Conf = '******';

Note that there's a major limitation with this approach: it doesn't let you properly exclude files. You can only specify a single exclude and you don't have full regular expression support. I found that to exclude directory "foobar" I had to use $Conf = ['?foobar']; (foobar by itself or anything I could think of using \ or / didn't work).

The smb approach seem to also require much more RAM than the rsyncmethod. Backing up lots of files with smb has been seen to cause theLinux kernel to start killing random tasks.

If you must use smb you might be better off mounting the remote file system beforehand and then backing up with tar as if it were part of the localhost backup.

Granting Access

Using rsync or tarassumes that the backuppc user on the BackupPC machine has permisisonto SSH to the client machine and log in as root without entering apassword. See SSH for more information. When complete you should be able to execute sudo -u backuppc ssh root@client on the BackupPC server and get logged in to the client without any password prompt.

Extras

$Conf is a handy way to prepare the client forthe backup. I use the following to take a snapshop of my MySQL databasebefore backing up:
$Conf = '$sshPath -l root $host /usr/bin/mysqldump -A -p****** > /var/backups/mysql_snapshot.sql';

Troubleshooting

The BackupPC FAQ is a good resource. The most important thing it mentions it to try running

sudo -u backuppc /usr/share/backuppc/bin/BackupPC_dump -v -f tomato

in order to view the full output of a verbose backup session on the command line.

Error writing to tar file - Connection reset by peer

I gotthis sometimes with really big (2GB) files stored on a Windows box(smbclient backup method). I ended up just excluding the files.

NT_STATUS_ACCESS_DENIED opening remote file

I was convinced this was BackupPC's fault but actually the permissionswere messed up on my Windows box. To fix, go to parent directory, setpermissions properly if needed, and explicitly propagate downoverwriding sub folders (via Advanced button). Default permissions fora standard folder are:

Administrators (RIA\Administrators)
Inherit Allow all except special permissions
CREATOR OWNER
Inherit Allow special permissions
Lorrin (RIA\Lorrin)
Inherit Allow special permissions
Note: this gets set to the CREATOR OWNER. So for C:\
it defaults to Everyone instead of a specific user.
SYSTEM
Inherit Allow all except special permissions
Users (RIA\Users)
Inherit Allow Read & Execute, List Folder Contents, Read, special permissions

Also "Backup Operators" don't have permission to read the user foldersinside "Documents and Settings". If you made the BackupPC account aBackup Operator instead of an Administrator and want to back up thosefolders add a Backup Operators (RIA\Backup Operators) entry with thepermissions to Read & Execute, List Folder Contents, Read.

Endless runs (tons of data)

Make sure you're not inadvertantly backing up mounted remote volumes (note all the excludes for Mac OS X above)

Endless runs (no data)

Perhaps you're getting stalled at

The authenticity of host 'calvin (192.168.123.3)' can't be established.
RSA key fingerprint is 0b:b2:fa:54:64:05:2c:6a:41:e5:1d:e5:4a:f4:a6:8d.
Are you sure you want to continue connecting (yes/no)?

Either manually ssh from backuppc's account to the host to be backed upor manually add the hosts info to ~backuppc/.ssh/known_hosts.

This can also happen if you're accidentally backing up mounted remotevolumes that are on a slow WAN and take impossibly long to traverse.

File RsyncP module doesn't exist

Install the libfile-rsyncp-perl package.

fileListReceive failed

This means something went seriously wrong with rsync. Check the client's dmesg- you might be running out of memory. rsync uses quite a bit (hundredsof MB) if you have many files and are doing a full backup. Note toself: make your swap parition bigger next time... I also saw this witha buggy non-release version of rsync.

You'll also see this if you forget to install rsync on the client. :-)

aborted by signal=ALRM

Make sure you're not backing up a folder full of non-file data such as /proc.

Check the $Conf setting; it's meant to bethe timeout between signals of life during the backup process but incertain cases acts as a timeout for the entire backup operation. Thedefault is only 7200 seconds (2 hours) and a backup can easily needmore time than that.

Also consider breaking the backup into smaller pieces. That requires two steps in the host's .pl file:

1. Define RsyncShareName to have multiple values instead of just /:

   $Conf = ['/', '/var/documents', '/var/media/pictures', '/var/media/music'];

2. Copy the RsyncArgs from config.pl and add the --one-file-system argument to it:

   $Conf = [
               #
               # Do not edit these!
               #
               '--numeric-ids',
               '--perms',
               '--owner',
               '--group',
               '--devices',
               '--links',
               '--times',
               '--block-size=2048',
               '--recursive',
   
               #
               # If you are using a patched client rsync that supports the
               # --checksum-seed option (see http://backuppc.sourceforge.net),
               # then uncomment this to enabled rsync checksum cachcing
               #
               #'--checksum-seed=32761',
   
               #
               # Add additional arguments here
               #
               '--one-file-system',
   ];

Restores fail

There are three places to check for details on what went wrong:

• the main LOG file (does it show the restore starting?)
• the per-PC LOG file (does it show the restore running?)
• the RestoreLOG file. It's available by clicking on the restorenumber on the per-PC summary page, and then clicking on the LOG link.

/usr/bin/xtar:: option requires an argument -- C

This shows in the restore log on a direct restore when the "Restore the files to share" field is left blank (instead of e.g. /) in the web form.

Tar exited with error 256 () status

This happens when the SSH connection fails to open.

"unknown host" error when starting a backup

This can happen if you have added a host to conf/hosts but forgotten to reload the config file.
Attachments: BackupPC_tarExtract.diff.xtar_support