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12 Original text<dmoore@jeffco.k12.co.us>
18 <oliva@dcc.unicamp.br>>
22 Corrections and additions<jam@philabs.research.philips.com>
26 Corrections and additions<ralf@atg.venture.de>
30 XML-conversion;Updates
36 Refer to http://www.amanda.org/docs/restore.html for the current version of
38 This document describes how to restore files backed up with Amanda either with
39 or without Amanda tools.
40 All these cases assume you're trying to restore a complete disk, that is,
41 you've replaced the lost disk with a new one, or created a new filesystem on
42 it. Tweaking with the arguments to restore (not amrestore), you will be able to
43 restore individual files.
44 Also, this text does not cover amrecover, a program that provides a text user
45 interface similar to interactive restore (restore -i), but it allows you to
46 select individual files to recover and automatically determines the tapes where
47 they were stored. The backups must be performed with the `index' option enabled
49 I considered the following cases.
50 The server machine (machine Aaron) runs solaris, the client machine (machine
53 1. Client machine fails, non-system critical.
54 Example: /home fails on Barney.
55 First, use amadmin to find the tapes most recently used to backup the
58 amadmin <config> info Barney '/home$'
60 Current info for Barney /home:
61 Stats: dump rates (kps), Full: 41.1, 33.1, 38.8
62 Incremental: 9.5, 2.1, 24.7
63 compressed size, Full: 63.1%, 54.0%, 52.9%
64 Incremental: 43.7%, 15.5%, 47.8%
65 Dumps: lev datestmp tape file origK compK secs
66 0 19971223 Barney01 16 329947 208032 5060
67 1 19980108 Barney16 8 1977 864 91
68 2 19971222 Barney06 7 1874 672 83
69 3 19970926 Barney03 11 12273 3040 211
71 This tells us that we will need two tapes to do a full restore (Barney01,
72 Barney16). Note that, even if Barney06 and Barney03 are listed, they are
73 actually older than the full backup, so they should not be used to restore
75 Log into Barney. Cd to the /home directory. Insert the tape with the level
76 0 dump on it into the tape drive of Aaron.
77 Become super-user in the client host and run (replace <amanda> with the
78 username under which amanda runs):
80 rsh -n -l <amanda> Aaron amrestore -p /dev/rmt/0cn Barney '/home\$' |
83 This requires client root to have login access to <amanda>@Aaron, with a
84 .rhosts entry (.amandahosts won't do). If you use ssh, you may be able to
85 type a password in order to be authenticated. Another alternative is to
86 start the operation in the server, and rsh to the client. You should be
87 the amanda user or root in the tape server and run:
89 amrestore -p /dev/rmt/0cn Barney '/home$' |
90 rsh Barney -l root /usr/etc/restore -ivbf 2 -
92 If you don't want to use rsh at all, you may run:
94 amrestore /dev/rmt/0cn Barney '/home$'
96 This should create a file whose name contains the hostname, directory
97 name, dump level and dump date of the backup. Now you have to move this
98 file to the client somehow: you may use NFS, rcp, ftp, floppy disks :-),
99 whatever. Suppose you rename that file to `home.0'. Then, on the client,
100 you should become root and run:
102 restore -ivbf 2 home.0
104 Repeat one of these steps, incrementing the level of the dump, until there
105 are no more available backups.
106 2. Client machine fails, system critical disk.
107 Example: / fails on Barney.
108 First of all, boot off the CD, and reinstall the system critical
109 partition, restoring it to vendor supplied state. Then, go through all of
111 3. Server machine fails, non-system critical, non-Amanda disk.
112 Proceed just as described in Scenario 1. However, you won't have to go
113 through the rsh process, because you can just use amrestore to replace the
115 4. Server machine fails, system critical, non-Amanda disk.
117 First of all, boot off the CD, and reinstall the system critical
118 partition, restoring it to vendor supplied state.
119 Then, follow steps in Scenario 3.
120 5. Server machine fails, non-system critical, Amanda disk, with db.
121 Example: /opt on Aaron
122 If the disk that contains the Amanda database is toast, then you need to
123 rebuild the database. The easiest way to do it is to take the text file
124 that you had mailed to you via the 'amadmin export' command, and import
125 via the 'amadmin import' command. Then you should be able to follow the
126 steps outlined in Scenario 4.
127 Note that Amanda does not mail the exported database automatically; you
128 may add this to the crontab entry that runs amanda.
129 Maybe it's a good idea to print out the text files as well and store the
130 last 2 dumpcycles worth of paper (the disc text files might have got
131 toasted as well). From the paper you still are able to reconstruct where
133 6. Server machine fails, non-system critical, Amanda disk, with binaries.
134 Example: /usr/local on Aaron
135 This is where things get hairy. If the disk with the amanda binaries on it
136 is toast, you have three options.
138 i. reinstall the Amanda binaries from another tape, on which you have
139 conveniently backed up the binaries within the last couple of weeks
141 ii. recompile Amanda, making sure not to overwrite your db files.
142 iii. use dd to read Amanda formatted tapes. This is the option I am going
143 to explore most fully, because this seems the most likely to occur.
145 a. Find out the device name used by Amanda, by looking in
146 amanda.conf. Turns out to be /dev/rmt/0cn for this system.
147 If amanda.conf isn't at hand: this must be a non-rewinding tape
148 device specifier (which I believe the trailing `n' stands for).
149 b. Look over the copy of the output of 'amadmin <config> export',
150 and find out which tapes /usr/local was backed up on.
151 c. Grab the tapes that /opt was backed up on, and stick the level 0
152 into the drive. cd to /usr/local.
153 d. Skip the first record, which is just the tape header, by using
154 the appropriate tape command.
156 mt -f /dev/rmt/0cn fsf 1
158 e. Now you want to start looking for /usr/local on this tape.
160 dd if=/dev/rmt/0cn bs=32k skip=1 | gzip -d | /usr/sbin/
163 This command gives us an interactive restore of this record,
164 including telling us what partition, what host, and what level
165 the backup was. The gzip -d portion of the pipe can be omitted
166 if there was no compression.
167 f. If you don't find /usr/local on the first try, quit ufsrestore,
168 and move forward one record.
170 mt -f /dev/rmt/0cn fsf 1
172 and try the dd/restore command shown above. Do this until you
173 find /opt on the disk.
174 Another possibility: quick and dirty tape index in case you
175 don't know which partition /usr/local was on: (from
176 <ralf@atg.venture.de>)
180 while mt -f $TAPEDEV fsf 1 ; do
181 dd if=$TAPEDEV bs=32k count=1 | head -1
187 Amanda: FILE 19971220 uri /root-sun4 lev 1 comp .gz program
189 Amanda: FILE 19971220 uri /misc lev 1 comp .gz program DUMP
190 Amanda: FILE 19971220 uri / lev 1 comp .gz program DUMP
192 g. Restore the Amanda binaries (what else do you need??), and then
193 bail out of ufsrestore. You can use amrestore, as in Scenario 3.
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200 Chapter 5. Backup PC hosts using Samba Home Part II. About Tapes and Changers
projects / debian / amanda / blob