Linux System Administration Recipes A Problem-Solution Approach

More documents

Recommendations

Info

CHAPTER 4 ■ TAKING BACKUPS AND MANAGING DATA4-4. Backing Up MySQLTo back up a MySQL database, you can use the mysqldump command:mysqldump -u root -pPASSWORD --single-transaction --all-databases > databasesbackup.sqlThis will back up all available databases on that server to the file databasesbackup.sql; to specify aparticular database, use the database name in place of –all-databases. If you’re doing this by hand, youcan leave out PASSWORD; the -p option with no argument will ask for the password on the command line.■ Note --single-transaction works for transactional tables (such as InnoDB and BDB), because it will dumpthe state of the database when the command was issued. MyISAM or MEMORY tables, however, could still changestate. For these types of tables, you can instead use the --lock-tables option. Bear in mind that tables fordifferent databases are locked separately, so there could be inconsistencies between databases (if somethingchanged in database 2 while database 1 was locked, for example). For MyISAM tables, another option is to use themysqlhotcopy utility, which is the fastest backup option.However, as with all backups, what you want is to automate it. Save the following script as/etc/cron.daily/mysqlbackup:01 #!/bin/bash02 dir="/usr/local/backups/"03 remotedir="/shared/raid/server_backups"04 mysqldir="${dir}ldap"05 filename="databases_"06 num=`date +%Y%m%d`07 mysqldump -u root -pPASSWORD --single-transaction –all-databases > ${mysqldir}${filename}${num}.ldif08 find $mysqldir -mtime +14 | xargs rm --09 cp $mysqldir/* $remotedirThis script saves a dump of the database in a local directory (${mysqldir}, line 07) and then copies itto a remote directory as well (line 09). The call to date on line 06 will produce files named for the datecreated, such as /var/backups/databasesbackup_20090711.sql, which means that you keep a history ofdatabase backups; line 08 clears out any backups older than two weeks so that you don’t end up overrunwith them.One obvious problem with this is that your MySQL root password is right there in plain text in thefile. Not very secure! A better bet is to create a user with minimal privileges (you can use SELECT, whicheffectively allows the user to view everything, and you can use LOCK TABLES so that the tables can belocked if need be) just for the purposes of backing up. Connect to your MySQL server as root (mysql -uroot -p), and issue this command:102Download at WoweBook.Com
CHAPTER 4 ■ TAKING BACKUPS AND MANAGING DATAmysql> grant SELECT,LOCK TABLES on *.* to backupuser@localhost identified by 'password';Then replace the username and password in line 07 of the previous script with the backup user’susername and password.To restore from one of these files, use the following command, which will ask for your rootpassword on the command line:mysql -u root -p databasename < databasesbackup_20090711.sqlYou’ll need to do this for each database.4-5. Backing Up Kerberos and LDAPIt’s important to back up your Kerberos and LDAP databases. A full regular backup should of courseinclude the files that Kerberos and LDAP use for their databases, but it’s also a good idea to keep aregularly updated dump of the databases elsewhere. This means that if you have corruption problems ora server goes down (although see recipes 2-7 and 2-8 for setting up slave/backup servers for LDAP andKerberos!), you can reload the information straightaway.This is exactly the sort of thing that cron is useful for. For LDAP, save this script as/etc/cron.daily/ldapbackup:01 #!/bin/bash02 dir="/usr/local/backups/"03 remotedir="/shared/raid/server_backups"04 dbdir="/var/lib/ldap/"05 ldap="ldap/"06 ldapdir="$dir$ldap"07 filename="database"08 num=`date +%Y%m%d`09 /etc/init.d/slapd stop > /dev/null10 cp -r $dbdir $dir11 /usr/sbin/slapcat -l ${ldapdir}${filename}${num}.ldif12 /etc/init.d/slapd start > /dev/null13 find $ldapdir -mtime +14 | xargs rm --14 cp $ldapdir/* $remotedirLines 02–08 set up the directory and the variables for the file names. The dump files will be savedwith names in the format database20090321.ldif in the /usr/local/backups/ldap/ directory. (Feel freeto change this to whatever you prefer.)Lines 09–12 stop LDAP to avoid problems with database inconsistencies, copy the contents of theLDAP database directory (/var/lib/ldap/) to the backup directory, and then dump the database as anLDIF file using slapcat. Then LDAP is restarted. (This should take only a second or two all told.)103Download at WoweBook.Com
Page 2:
Download at WoweBook.Com
Page 5 and 6:
Download at WoweBook.Comiii
Page 7 and 8:
Contents■About the Author .......
Page 9 and 10:
■ CONTENTS3-7. Writing a Nagios P
Page 11 and 12:
■ CONTENTS■Chapter 8: Using the
Page 13 and 14:
■ CONTENTSAbout the Author■Juli
Page 15 and 16:
■ CONTENTSAcknowledgmentsMany tha
Page 17 and 18:
■ CONTENTSIntroductionThis book i
Page 19 and 20:
■ INTRODUCTIONDownloading the Cod
Page 21 and 22:
C H A P T E R 1■ ■ ■Saving Yo
Page 23 and 24:
CHAPTER 1 ■ SAVING YOURSELF EFFOR
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
C H A P T E R 2■ ■ ■Centraliz
Page 43 and 44:
CHAPTER 2 ■ CENTRALIZING YOUR NET
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72: CHAPTER 2 ■ CENTRALIZING YOUR NET
Page 83 and 84: C H A P T E R 3■ ■ ■Monitorin
Page 85 and 86: CHAPTER 3 ■ MONITORING AND UPDATI
Page 115 and 116: C H A P T E R 4■ ■ ■Taking Ba
Page 117 and 118: CHAPTER 4 ■ TAKING BACKUPS AND MA
Page 121: CHAPTER 4 ■ TAKING BACKUPS AND MA
Page 139 and 140: C H A P T E R 5■ ■ ■Working w
Page 141 and 142: CHAPTER 5 ■ WORKING WITH FILESYST
Page 155 and 156: C H A P T E R 6■ ■ ■Securing
Page 157 and 158: CHAPTER 6 ■ SECURING YOUR SYSTEMS
Page 173 and 174:
CHAPTER 6 ■ SECURING YOUR SYSTEMS
Page 175 and 176:
CHAPTER 6 ■ SECURING YOUR SYSTEMS
Page 177 and 178:
C H A P T E R 7■ ■ ■Working w
Page 179 and 180:
CHAPTER 7 ■ WORKING WITH APACHEOn
Page 181 and 182:
CHAPTER 7 ■ WORKING WITH APACHEdi
Page 183 and 184:
CHAPTER 7 ■ WORKING WITH APACHE4.
Page 185 and 186:
CHAPTER 7 ■ WORKING WITH APACHE
Page 187 and 188:
CHAPTER 7 ■ WORKING WITH APACHEAl
Page 189 and 190:
CHAPTER 7 ■ WORKING WITH APACHE
Page 191 and 192:
C H A P T E R 8■ ■ ■Making Be
Page 193 and 194:
CHAPTER 8 ■ USING THE COMMAND LIN
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
C H A P T E R 9■ ■ ■Working w
Page 207 and 208:
CHAPTER 9 ■ WORKING WITH TEXT IN
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
C H A P T E R 10■ ■ ■Things G
Page 225 and 226:
CHAPTER 10 ■ THINGS GO IN, THINGS
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
C H A P T E R 11■ ■ ■Tracking
Page 235 and 236:
CHAPTER 11 ■ TRACKING DOWN BUGSTh
Page 237 and 238:
CHAPTER 11 ■ TRACKING DOWN BUGS01
Page 239 and 240:
CHAPTER 11 ■ TRACKING DOWN BUGS
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
CHAPTER 11 ■ TRACKING DOWN BUGSTh
Page 247 and 248:
CHAPTER 11 ■ TRACKING DOWN BUGSAn
Page 249 and 250:
CHAPTER 11 ■ TRACKING DOWN BUGS#
Page 251 and 252:
C H A P T E R 12■ ■ ■Managing
Page 253 and 254:
CHAPTER 12 ■ MANAGING TIME AND PE
Page 255 and 256:
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
APPENDIX■ ■ ■Perl TipsSee rec
Page 269 and 270:
APPENDIX ■ PERL TIPS• Date::Par
Page 271 and 272:
APPENDIX ■ PERL TIPSPerl Syntax N
Page 273 and 274:
■ ■ ■Index■Symbols$CDPATH,
Page 275 and 276:
■ INDEXenscript option (printing)
Page 277 and 278:
■ INDEX■NNagiosadding hosts to,
Page 279 and 280:
■ INDEXsyslogcentralized logging
Page 281 and 282:
Download at WoweBook.Com
show all

Linux System Administration Recipes A Problem-Solution Approach

Create successful ePaper yourself

Delete template?

Save as template?