Linux Complete Backup and Recovery HOWTO 2002 January 20
CharlesCurleyccurley at trib dot com1.22003-02-12c^2Added Red Hat 8.0 notes, support for FAT32, split the first stage restore scripts, and other minor changes. Notes on Amanda.1.12002-09-10c^2New code to handle ext3 partitions in make.fdisk, and a note on initrd.1.02002-07-24c^2We now use bz2 compression in the first stage, have the run time option to check for bad blocks, and have a script that runs the entire first stage.0.052002-07-04c^2Added another variation, other minor fixes.0.042002-05-09c^2Added Theme ent Variations section, a variation; also some minor reorganization.0.032002-04-09c^2Added the Beeblebrox Project to resources.0.022002-01-27c^2Added Mondo to resources0.012001-10-25c^2Initial version for LDP releaseImagine your disk drive has just become a very expensive hockey puck. Imagine you have had a fire, and your computer case now looks like something Salvador Dalent would like to paint. Now what?Total restore, sometimes called bare metal recovery, is the process of rebuilding a computer after a catastrophic failure. In order to make a total restoration, you must have complete backups, not only of your file system, but of partition information and other data. This HOWTO is a step-by-step tutorial on how to back up a Linux computer so as to be able to make a bare metal recovery, and how to make that bare metal recovery. It includes some related scripts.IntroductionThe normal bare metal restoration process is: install the operating system from the product disks. Install the backup software, so you can restore your data. Restore your data. Then you get to restore functionality by verifying your configuration files, permissions, etc. The process and scripts explained in this HOWTO will save re-installing the operating system. The process explained here will restore only files that were backed up from the production computer. Your configuration will be intact when you restore the system, which should save you hours of verifying configurations and data.Copyright InformationCopyright ent 2001, 2002 Charles Curley and distributed under the terms of the GNU Free Documentation License (GFDL) license, stated below. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License. If you have any questions, please contact linux-howto at metalab.unc.edu. Disclaimers No liability for the contents of this documents can be accepted by the author, the Linux Documentation Project or anyone else. Use the concepts, examples and other content at your own risk. There may be errors and inaccuracies that may be damaging to your system. Proceed with caution, and although errors are unlikely, the author(s) take no responsibility for them. All copyrights are held by their by their respective owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark. Naming of particular products or brands should not be seen
as endorsements.
You are strongly recommended to take a backup of your system
before major installation and backups at regular intervals.
In addition, you are strongly recommended to use a sacrificial experimental computer when mucking with the material, espcially the scripts, in this HOWTO.New VersionsYou can find this document at its home page or at the Linux Documentation Project homepage in many formats. Please comment to ccurley at trib dot combzip2 compressed chunky (lots of small pages. Faster reading.) HTML.
bzip2 compressed smooth (one monster page -- no chunks. Easier to search.) HTML.
bzip2 compressed postscript (US letter format).
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Use the source, Luke.CreditsThis document is derived from two articles originally published in
Linux Journal. My thanks to
Linux Journal for reverting the rights to those articles, thereby helping make this HOWTO possible.
Thanks to Joy Y Goodreau for excellent HOWTO editing.Feedback Feedback is most certainly welcome for this document. Without your corrections, suggestions and other input, this document wouldn't exist. Please send your additions, comments and criticisms to me at: ccurley at trib.com.Translations Not everyone speaks English. Volunteers are welcome.
Overview The process shown below is not easy, and can be hazardous to your data. Practice it before you need it! Do as I did, and practice on a sacrificial computer!
The target computer for this HOWTO is a Pentium computer with a Red Hat 7.1 Linux server or workstation installation on one IDE hard drive. The target computer does not have vast amounts of data because the computer was set up as a sacrificial test bed. That is, I did not want to test this process with a production computer and production data. Also, I did a fresh installation before I started the testing so that I could always re-install if I needed to revert to a known configuration.
NOTEThe sample commands will show, in most cases, what I had to type to recover the target system. You may have to use similar commands, but with different parameters. It is up to you to be sure you duplicate your setup, and not the test computer's setup. The basic procedure is set out in W. Curtis Preston, Unix Backup ent Recovery, O'Reilly ent Associates, 1999, which I have favorably reviewed in Linux Journal. However, the book is a bit thin on specific, real-time questions. For example, exactly which files do you back up? What metadata do you need to preserve, and how?
Before beginning the process set forth in this HOWTO you will need to back up your system with a typical backup tool such as Amanda, BRU, tar, Arkeia or cpio. The question, then, is how to get from toasted hardware to the point where you can run the restoration tool that will restore your data.
Users of Red Hat Package Manager (RPM) based Linux distributions should also save RPM metadata as part of their normal backups. Something like:
bash# rpm -Va ent /etc/rpmVa.txt in your backup script will give you a basis for comparison after a bare metal restoration.
To get to this point, you need to have:
Your hardware up and running again, with replacement components as needed. The BIOS should be correctly configured, including time and date, and hard drive parameters. At the moment, there is no provision for using a different hard drive.
A parallel port IomegaZIP drive or equivalent. You will need at least 30 MB of space. Your backup media.
A minimal Linux system that will allow you to run the restoration software.
To get there, you need at least two stages of backup, and possibly three. Exactly what you back up and in which stage you back it up is determined by your restoration process. For example, if you are restoring a tape server, you may not need networking during the restoration process. So only back up networking in your regular backups.
You will restore in stages as well. In stage one, we build partitions, file systems, etc. and restore a minimal file system from the ZIP disk. The goal of stage one is to be able to boot to a running computer with a network connection, tape drives, restoration software, or whatever we need for stage two.
The second stage, if it is necessary, consists of restoring backup software and any relevant databases. For example, suppose you use Arkeia and you are building a bare metal recovery ZIP disk for your backup server. Arkeia keeps a huge database on the server's hard drives. You can recover the database from the tapes, if you want. Instead, why not tar and gzip the whole arkeia directory (at /usr/knox), and save that to another computer over nfs or ssh? Stage one, as we have defined it below, does not include X, so you will have some experimenting to do if you wish to back up X as well as your backup program. Some restore programs require X.
Of course, if you are using some other backup program, you may have some detective work to do to. You will have to find out the directories and files it needs to run. If you use tar, gzip, cpio, mt or dd for your backup and recovery tools, they will be saved to and restored from our ZIP disk as part of the stage one process describe below.
The last stage is a total restoration from tape or other media. After you have done that last stage, you should be able to boot to a fully restored and operational system.
LimitationsThis HOWTO is restricted to making a minimal backup such that, having then restored that backup to new hardware (bare metal), you can then use your regular backups to restore a completely working system. This HOWTO does not deal with your regular backups at all.Even within that narrow brief, this HOWTO is not exhaustive. You still have some research, script editing, and testing to do.The scripts here restore the partition data exactly as found on the source hard drive. This is nice if you are restoring on an identical computer or at least and identical hard drive, but that is often not the case. For now, there are two remedies (which will make more sense after you've read the rest of the HOWTO):Edit the partition table input file. I've done that a few times. You can also do this to add new partitions or delete existing ones (but edit the scripts that use the partition table input file as well).Hand build a new partition table and go from there. That is one reason why restore.metadata does not call the hard drive rebuilding script. Use the rebuilding script.The scripts shown here only handle ext2fs, FAT12, FAT16 and FAT32. Until some eager volunteer supplies code for doing so in these scripts, you will need other tools for backing up and restoring file systems we haven't covered. Partition Image looks like a useful candidate here.PreparationWARNING Do your normal backups on their regular schedule. This HOWTO is useless if you don't do that.
Build yourself a rescue disk. I use tomsrtbt. It is well documented and packs a lot of useful tools onto one floppy diskette. There is an active list for it, and the few questions I've had were quickly and accurately answered. I like that in a product my shop may depend on one day.
Next, figure out how to do the operating system backup you will need so that you can restore your normal backup. I followed Preston's advice and used an Iomega parallel port ZIP drive. The drives get approximately 90 MB of useful storage to a disk. I need about 85 MB to back up my desktop, so a 100MB ZIP drive may be pushing your luck.
Installing the ZIP Drive Installing the ZIP drive is covered in the ZIP Drive HOWTO, available at the Linux Documentation Project and at its home page, http://www.njtcom.com/dansie/zip-drive.html.
Creating the Stage 1 Back Up Having made your production backups, you need to preserve your partition information so that you can rebuild your partitions.
The script make.fdisk scans a hard drive for partition information, and saves it in three files. The first is an executable script, called make.dev.x (where x is the name of the device file, e.g. hda). Second is mount.dev.x, which creates mount points and mounts the newly created partitions on them. The last, dev.x, is the commands necessary for fdisk to build the partitions. You specify which hard drive you want to build scripts for (and thus the file names) by naming the associated device file as the argument to make.fdisk. For example, on a typical IDE system,
bash# make.fdisk /dev/hda spits out the scripts make.dev.hda, mount.dev.hda and the input file for fdisk, dev.hda.In addition, if make.fdisk encounters a FAT partition, it preserves the partition's boot sector in a file named dev.xy, where x is the drive's device name (e.g. sdc, hda) and y is the partition number. The boot sector is the first sector, 512 bytes, of the partition. This sector is restored at the same time the partitions are rebuilt, in the script make.dev.hda Fortunately, the price of hard drives is plummeting almost as fast as the public's trust in politicians after an election. So it is good that the output files are text, and allow hand editing. Right now, that's the only way to rebuild on a larger replacement drive. (See the To Do list.)
Other metadata are preserved in the script save.metadata. The script saves the partition information in the file fdisk.hda in the root of the ZIP disk. It is a good idea to print this file and your /etc/fstab so that you have hard copy should you ever have to restore the partition data manually. You can save a tree by toggling between two virtual consoles, running fdisk in one and catting /etc/fstab or /fdisk.hda as needed. However, doing so is error prone.
You will also want to preserve files relevant to your restoration method. For example, if you use nfs to save your data, you will need to preserve hosts.allow, hosts.deny, exports, etc. Also, if you are using any network-backed restoration process, such as Amanda or Quick Restore, you will need to preserve networking files like HOSTNAME, hosts, etc. and the relevant software tree.
The simplest way to handle these and similar questions is to preserve the entire etc directory.
There is no way a 100 MB ZIP drive is going to hold a server installation of a modern distribution of Linux. We have to be much more selective than simply preserving the whole kazoo. What files do we need?
The boot directory.
The /etc directory and subdirectories.
Directories needed at boot time.
Device files in /dev.
To determine the directories needed at boot, we look at the boot initialization file /etc/rc.sysinit. It sets its own path like so:
PATH=/bin:/sbin:/usr/bin:/usr/sbin
export PATH Trial and error indicated that we needed some other directories as well, such as /dev. In Linux, you can't do much without device files.
In reading the script save.metadata, note that we aren't necessarily saving files that are called with absolute paths.
We may require several iterations of back up, test the bare metal restore, re-install from CD and try again, before we have a working backup script. While I worked on this HOWTO, I made five such iterations before I had a successful restoration. That is one reason why it is essential to use scripts whenever possible. Test thoroughly!
One thing you can do on an RPM based system is use the rpm program to determine which files are where. For example, to get a complete list of the files used by the openssh package, run:bash# rpm -ql opensshThere are somethings you don't need. like the man pages. You can inspect each one and decide whether to back it up or not.Theme And VariationsNo ZIP driveThis backup process requires you to have the ZIP disk drive present at each backup. You could, given a large enough hard drive, create the ZIP disk's contents in a directory, and back that up over the net. Then you only need to build a ZIP disk (with cp -rp) on the backup server when you need to restore.The backup process will be faster, but you should check that the resulting directory will fit on your ZIP disk (with du -hs $target.zip)! You will have to edit the definition of the variable zip in save.metadata.My laptop has problems running both a network card and a ZIP drive, so this is the process I use to back it up.Alternatively, you could build several ZIP disks' worth of backup on the hard drive, and feed them to the system on restore.Multiple ZIP disksBy splitting up the two first stage scripts, restore.metadata and save.metadata, you could spread the first stage metadata across multiple ZIP disks.Excluding From First Stage SavingThere are time when you need to squeeze a few megabytes from the first stage data, expecially when you are pushing the limit of your ZIP disk. The function crunch in the script save.metadata takes multiple parameters to feed to tar. It can also take the --exclude parameter. So, for example, you can exclude emacs and gs like so:crunch etc etc --exclude etc/samba --exclude X11Why those two? Because they're hard drive space hogs and we don't need them at boot time.How to find good candidates for exclusion? List the target directories with ls -alSr for individual files, and du | sort -n for directories.InitrdIf your system uses an initial RAM disk, or initrd, to boot, make sure that save.metadata creates the directory /initrd. The easiest way to do this is to ensure that it is included in the list of directories used in the directory creating loop toward the end.Your system will probably use an initrd if it boots from a SCSI drive or has root on an ext3fs partition. Check /etc/lilo.conf to see if it calls for one.First Stage RestoreBooting tomsrtbt The first thing to do before starting the restoration process is to verify that the hardware time is set correctly. Use the BIOS setup for this. How close to exact you have to set the time depends on your applications. For restoration, within a few minutes of exact time should be accurate enough. This will allow time-critical events to pick up where they left off when you finally launch the restored system.
Before booting tomsrtbt, make sure your ZIP drive is placed on a parallel port, either /dev/lp0 or /dev/lp1. The start-up software will load the parallel port ZIP drive driver for you.
The next step is to set the video mode. I usually like to see as much on the screen as I can. When the option to select a video mode comes, I use mode 6, 80 columns by 60 lines. Your hardware may or may not be able to handle high resolutions like that, so experiment with it.
Restoration Once tomsrtbt has booted and you have a console, mount the ZIP drive. It is probably a good idea to mount it read only:
# mount /dev/sda1 /mnt -o ro Check to be sure it is there:
# ls -l /mntAt this point, you can run the restoration automatically or manually. Use the automated restore if you don't need to make any changes as you go along.One consideration here is whether you have multiple hard drives. If your Linux installation mounts partitions on multiple hard drives, you must mount the root partition first. This is to ensure that mount point directories are created on the partition where they belong. The script first.stage will run the scripts to mount the drives in the order in which they are created. If you have created them (in the script save.metadata) in the order in which they cascade from root, the mounting process should work just fine.If you have multiple hard drives, and they cross-mount, you are on your own. Either combine and edit the scripts to mount them in the correct order, or do it manually.AutomatedTo run the first stage restore completely automated, enter the command:# /mnt/root.bin/first.stageIf you want to check for back blocks, add the -c option.Manually To run the process manually, change to the directory where the scripts are on the ZIP drive.
# cd /mnt/root.bin Now run the script(s) that will restore the partition information and create file systems. You may run them in any order. e.g.:
# ./make.dev.hdaIf you want to check for back blocks, add the -c option. This script will:
Clean out the first 1024 bytes of the hard drive, killing off any existing partition table and master boot record (MBR).
Recreate the partitions from the information gathered when you ran make.fdisk.
Make ext2 and ext3 file system partitions and Linux swap partitions as appropriate. If you provide the -c option to the script, it will also check for bad blocks.
Make some types of FAT partitions.
NOTEIf you have other operating systems to restore, now is a good time to do so. When you've done that, reboot to tomsrtbt and continue restoring Linux.Now run the script(s) that create mount points and mount the partitions to them.# ./mount.dev.hda Once you have created all your directories and mounted partitions to them, you can run the script restore.metadata. This will restore the contents of the ZIP drive to the hard drive.
You should see a directory of the ZIP disk's root directory, then a list of the archive files as they are restored. Tar on tomsrtbt will tell you that tar's block size is 20, and that's fine. You can ignore it. Be sure that lilo prints out its results:
Added linux * That will be followed by the output from a df -m command.
Finishing Touches If you normally boot directly to X, you could have some problems. To be safe, change your boot run level temporarily. In /target/etc/inittab, find the line that looks like this:
id:5:initdefault: and change it to this:
id:3:initdefault: Now, you can gracefully reboot. Remove the tomsrtbt floppy from your floppy drive if you haven't already done so, and give the computer the three fingered salute, or its equivalent:rebootThe computer will shut down and reboot.Second Stage Restoration As the computer reboots, go back to the BIOS and verify that the clock is more or less correct.
Once you have verified the clock is correct, exit the BIOS and reboot to the hard drive. You can simply let the computer boot in its normal sequence. You will see a lot of error messages, mostly along the lines of I can't find blah! Waahhh! If you have done your homework correctly up until now, those error messages won't matter. You don't need linuxconf or apache to do what you need to do.
NOTEAs an alternative, you can boot to single user mode (at the lilo prompt, enter linux single), but you will have to configure your network manually and fire up sshd or whatever daemons you need to restore your system. How you do those things is very system specific. You should be able to log into a root console (no X -- no users, sorry). You should now be able to use the network, for example to nfs mount the backup of your system.
If you did the two stage backup I suggested for Arkeia, you can now restore Arkeia's database and executables. You should be able to run /etc/rc.d/init.d/arkeia start and start the server. If you have the GUI installed on another computer with X installed, you should now be able to log in to Arkeia on your tape server, and prepare your restoration.
NOTEWhen you restore, read the documentation for your restoration programs carefully. For example, tar does not normally restore certain characteristics of files, like suid bits. File permissions are set by the user's umask. To restore your files exactly as you saved them, use tar's p option. Similarly, make sure your restoration software will restore everything exactly as you saved it.
To restore the test computer:
bash# restore.all If you used tar for your backup and restoration, and used the -k (keep old files, don't overwrite) option, you will see a lot of this:
tar: usr/sbin/rpcinfo: Could not create file: File exists
tar: usr/sbin/zdump: Could not create file: File exists
tar: usr/sbin/zic: Could not create file: File exists
tar: usr/sbin/ab: Could not create file: File exists This is normal, as tar is refusing to overwrite files you restored during the first stage of restoration.
Then reboot. On the way down, you will see a lot of error messages, such as no such pid. This is a normal part of the process. The shutdown code is using the pid files from daemons that were running when the backup was made to shut down daemons that were not started on the last boot. Of course there's no such pid.
Your system should come up normally, with a lot fewer errors than it had before, ideally no errors. The acid test of how well your restore works on an RPM based system is to verify all packages:
bash# rpm -Va Some files, such as configuration and log files, will have changed in the normal course of things, and you should be able to mentally filter those out of the report. You can redirect the output to a file, and diff it against the one that was made at backup time (/etc/rpmVa.txt), thereby speeding up this step considerably. Emacs users should check out its diff facilities.
Now you should be up and running. It is time to test your applications, especially those that run as daemons. The more sophisticated the application, the more testing you may need to do. If you have remote users, disable them from using the system, or make it read only while you test it. This is especially important for databases, to prevent making any corruption or data loss worse than it already might be.
If you normally boot to X, and disabled it above, test X before you re-enable it. Re-enable it by changing that one line in /etc/inittab back to:
id:5:initdefault: You should now be ready for rock and roll -- and some aspirin and a couch.
Distribution Specific Notes Below are distribution notes from past experiences. If you have additional notes that you would like to add for other distributions, please forward them to me.
Red Hat 8.0Red Hat 8.0 requires changes only if you log in via ssh to your computer after the first stage restore. If, say, you perform the second state restore over ssh. If so, make the following changes:In the file save.metadata, add the kerberos libraries to the first stage backup.crunch kerberos usr/kerberos/lib/In the file restore.metadata, there is a loop that builds several directories. First, add these two directory names to the list: /var/empty/sshd and /var/lock/subsys. As Red Hat 8.0 defaults to ext3fs, it requires an inital RAM disk at boot time. So make sure initrd is in the list. Then, if it isn't already there, add the -p switch to the makdir command.The directory /var/lock/subsys is owned by group lock, so change its owner.chroot $target /bin/chown root:lock /var/lockFinally, usr/lib/libcrypto* has gone away, so you can remove that from the line that crunches usr/lib. Red Hat 7.1 This distribution is the one I used originally on my test computer. I have had no problems with it.
Red Hat 7.0 This version seems to require libcrack (in /usr/lib) and its attendant files in order to authenticate users. So in save.metadata, add to the line that saves /usr/lib the following: /usr/lib/*crack* and enable that line.
Application Specific Notes I have listed below notes about backing up particular applications.
SquidSquid is a http proxy and cache. As such it keeps a lot of temporary data on the hard drive. There is no point in backing that up. Insert --exclude /var/spool/squid into the appropriate tar command in your second stage backup script. Then, get squid to rebuild its directory structure for you. Tack onto the tail end of the second stage restore script a command for squid to initialize itself. Here is how I did it over ssh in restore.tester:ssh $target "mkdir /var/spool/squid ; chown squid:squid /var/spool/squid;\
/usr/sbin/squid -z;touch /var/spool/squid/.OPB_NOBACKUP"The last command creates a file of length 0 called .OPB_NOBACKUP. This is for the benefit of Arkeia, and tells Arkeia not to back up below this directoryArkeiaThese notes are based on testing with Arkeia 4.2.Arkeia is a backup and restore program that runs on a wide variety of platforms. You can use Arkeia as part of a bare metal restoration scheme, but there are two caveats.The first is probably the most problematic, as absent any more elegant solution you have to hand select the directories to restore in the navigator at restoration time. The reason is that, apparently, Arkeia has no mechanism for not restoring files already present on the disk, nothing anlogous to tar's -p option. If you simply allow a full restore, the restore will crash as Arkeia over-writes a library which is in use at restore time, e.g. lib/libc-2.1.1.so. Hand selection of directories to restore is at best dicy, so I recommend against it.The second caveat is that you have to back up the Arkeia data dictionary and/or programs. To do that, modify the save.metatdata script by adding Arkeia to the list of directories to save:# arkeia specific:
tar cf - usr/knox | gzip -c ent $zip/arkeia.tar.gzYou must back up the data dictionary this way because Arkeia does not back up the data dictionary. This is one of my complaints about Arkeia, and I solve it on my own computer by saving the data dictionary to tape with The TOLIS Group's BRU.The data dictionary will be restored in the script restore.metadata automatically.AmandaAmanda (The Advanced Maryland Automatic Network Disk Archiver) works quite well with this set of scripts. Use the normal Amanda back-up process, and build your first stage data as usual. Amanda stores the data on tape in GNU tar or cpio format, and you can recover from individual files to entire backup images. The nice thing about recovering entire images is that you can then use variants on the scripts in this HOWTO to restore from the images, or direct from tape. I was able to restore my test machine with the directions from W. Curtis Preston's Unix Backup ent Recovery. For more information on it, see the Resources. The Amanda chapter from the book is on line.I made two changes to the script restore.tester. First, I changed it to accept a file name as an argument. Then, since Amanda's amrestore decompresses the data as it restores it, I rewrote it to cat the file into the pipe instead of decompressing it.The resulting line looks like this:cat $file | ssh $target "umask 000 ; cd / ; tar -xpkf - "where $file is the script's argument, the image recovered from the tape by amrestore.Since the command line arguments to tar prohibit over-writing, restore from images in the reverse of the order in which they were made. Restore most recent first.Some Advice for Disaster Recovery You should take your ZIP disk for each computer and the printouts you made, and place them in a secure location in your shop. You should store copies of these in your off-site backup storage location. The major purpose of off-site backup storage is to enable disaster recovery, and restoring each host onto replacement hardware is a part of disaster recovery.
You should also have several tomsrtbt floppies and possibly some ZIP drives in your off-site storage as well. Also, have copies of the tomsrtbt distribution on several of your computers so that they back each other up.
You should probably have copies of this HOWTO, with your site-specific annotations on it, with your backups and in your off-site backup storage.
What Now? This HOWTO results from experiments on one computer. No doubt you will find some directories or files you need to back up in your first stage backup. I have not dealt with saving and restoring X on the first stage, nor have I touched at all on processors other than Intel.
I would appreciate your feedback as you test and improve these scripts on your own computers. I also encourage vendors of backup software to document how to do a minimal backup of their products. I'd like to see the whole Linux community sleep just a little better at night.
To Do Volunteers are most welcome. Check with me before you start on one of these in case someone else is working on it already.
A partition editor to adjust partition boundaries for a different hard drive, or the same one with different geometry, or to adjust partition sizes within the same hard drive. A GUI would probably be a good idea here. On the other tentacle, the FSF's parted looks like it will fill part of the bill. It does re-size existing partitions, but with restrictions.
make.fdisk currently only recognizes some FAT partitions, not all. Add code to make.fdisk to recognize others and make appropriate instructions to rebuild them in the output files.
For FAT12 or FAT16 partitions we do not format, write zeros into the partition so that Mess-DOS 6.x does not get confused. See the notes on fdisk for an explanation of the problem. Make a script for putting ext2/3 file systems on ZIP disks.
Translations into other (human) languages.
Find out how loadlin or similar programs affect this process.Changes for GRUBChange the scripts to use a CD-ROM. A CD-ROM that would boot to tomsrtbt, with the first stage restore data on the rest of it, would be just the ticket.I've referred to Red Hat Package Manager (rpm) from time to time. What are the equivalent deb commands?The Scripts See the notes in the beginning of each script for a summary of what it does.
First Stage<filename moreinfo="none">make.fdisk</filename> This script, run at backup time, creates scripts similar to make.dev.hda and mount.dev.x, below, for you to run at restore time. It also produces data files similar to dev.hda, below. The name of the script and data file produced depends on the device given this script as a a parameter. That script, run at restore time, builds the partitions on the hard drive. make.fdisk is called from save.metadata, below.
<filename moreinfo="none">make.dev.hda</filename>This script is a sample of the sort produced by make.fdisk, above. It uses data files like dev.hda, below. It builds partitions and puts file systems on some of them. This is the first script run at restore time.If you are brave enough to edit dev.hda (q.v.), say, to add a new partition, you may need to edit this script as well.If you want make.dev.hda to check for bad blocks when it puts a file system on the partitions, use a ent-cent command line option.<filename moreinfo="none">mount.dev.hda</filename>This script is a sample of the sort produced by make.fdisk, above. It builds mount points and mounts partitions on them, making the target file system ready for restoring files. This is the second script run at restore time.If you are brave enough to edit dev.hda (q.v.), say, to add a new partition, you may need to edit this script as well.<filename moreinfo="none">dev.hda</filename>This data file is used at restore time. It is fed to fdisk by the script make.dev.hda. It is produced at backup time by make.fdisk. Those familiar with fdisk will recognize that each line is an fdisk command or value, such as a cylinder number. Thus, it is possible to change the partition sizes and add new partitions by editing this file. That's why the penultimate command is v, to verify the partition table before it is written.<filename moreinfo="none">save.metadata</filename> This is the first script to run as part of the backup process. It calls make.fdisk, above. If you have a SCSI hard drive or multiple hard drives to back up, edit the call to make.fdisk appropriately.
<filename moreinfo="none">restore.metadata</filename> This script restores metadata from the ZIP disk as a first stage restore.
<filename moreinfo="none">first.stage</filename>This script runs the entire first stage restore with no operator intervention.If you want to check for bad blocks when it puts a file system on the partitions, use a ent-cent command line option.Second Stage These scripts run on the computer being backed up or restored.
<filename moreinfo="none">back.up.all</filename> This script saves to another computer via an NFS mount. You can adapt it to save to tape drives or other media.
<filename moreinfo="none">back.up.all.ssh</filename> This script does exactly what back.up.all does, but it uses ssh instead of nfs.
<filename moreinfo="none">restore.all</filename> This is the restore script to use if you backed up using back.up.all.
<filename moreinfo="none">restore.all.ssh</filename> This is the restoration script to use if you used back.up.all.ssh to back up.
Backup Server ScriptsThe ssh scripts above have a possible security problem. If you run them on a firewall, the firewall has to have access via ssh to the backup server. In that case, a clever cracker might also be able to crack the backup server. It would be more secure to run backup and restore scripts on the backup server, and let the backup server have access to the firewall. That is what these scripts are for. Rename them to get.x and restore.x where x is the name of the target computer. Edit them (the variable enttarget's initialization) to use the target computer's host name, or rewrite them to use a command line argument.These scripts backup and restore the target completely, not just the stage one backup and restore. Also, note that get.tester backs up the ZIP disk as well, in case you need to replace a faulty ZIP disk.I use these scripts routinely.<filename moreinfo="none">get.tester</filename><filename moreinfo="none">restore.tester</filename>ResourcesIn no particular order. These are things you might want to investigate for yourself. A listing here should not be taken as an endorsement. In fact, in many case I have not used the product and cannot comment on it.W. Curtis Preston's excellent Unix Backup ent Recovery. This is the book that got me started on this bare metal recovery stuff. I highly recommend it; read my review.A list of small Linux disties.tomsrtbt, The most Linux on 1 floppy disk. Tom also has links to other small disties.The Linux Documentation Project. See particularly the LILO, Linux Crash Rescue HOW-TOThe Free Software Foundation's parted for editing (enlarging, shrinking, moving) partitions.Partition Image for backing up partitions.From the web page: Partition Image is a Linux/UNIX utility which saves partitions in many formats (see below) to an image file. The image file can be compressed in the GZIP/BZIP2 formats to save disk space, and split into multiple files to be copied on removable floppies (ZIP for example), .... The partition can be saved across the network since version 0.6.0.Hugo Rabson's Mondo... creates one or more bootable Rescue CD's (or tape+floppies) containing some or all of your filesystem. In the event of catastrophic data loss, you will be able to restore from bare metal.Bacula is a GLPled backup product which has bare metal recovery code inspired in part by this HOWTO.The Crash Recovery Kit for LinuxThe Beeblebrox Project looks promising.GNU Free Documentation LicenseVersion 1.1, March 2000
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