Managing Software Packages and File Systems

1
Managing Software Packages and File Systems

• Chapter Ten

2
Managing Packages

• Linux groups related files into packages for
  easier management
• Software package contains all files needed to
  install and use application
• Red Hat Package Manager format
• Abbreviated as rpm
• Debian Package Manager format
• Abbreviated as deb

3
Managing Packages (continued)

• Debian package format
• Used by the Debian Linux distribution
• .deb file extension
• dpkg old form for installing packages
• apt Advanced Packaging Tool
• dselect - utility manages Debian packages

4
Managing Packages Graphically

• Use graphical utility to change what is installed
• To start utility, enter Red-Hat
  system-config-packages in terminal window
• Select check box next to any category of packages
  to add packages from category
• Details link lists individual software packages
  included in category

5
Managing Packages Graphically (continued)
6
Synaptic Package Manager in Ubuntu
7
Using rpm to Manage Software Packages

• rpm command-line utility maintains database
  listing all software packages installed on system
• Lists
• Files included in each package
• Packages are dependent on other packages
• Other information
• rpm command
• Install new software packages
• Erase software packages from system

8
Using rpm to Manage Software Packages (continued)

• Name of package file includes version information
• Example
• gedit-2.4.0-3.i386.rpm
• Version 2.4.0
• Release code 3
• Platform i386

9
Using rpm to Manage Software Packages (continued)

• Rpm command options fall into categories
• -q option?query database and learn about packages
• -i or -U option?install or upgrade package
• -e option?erase (uninstall) rpm package
• Options can be used in combination
• Install new rpm files either from
• Linux CD-ROM
• Internet

10
Using rpm to Manage Software Packages (continued)

• Install package zsh-4.2.0-1.i386.rpm
• rpm -uvh /tmp/zsh-4.2.0-1.i386.rpm
• Can use regular expression to specify package
  names
• rpm utility maintains internal database of keys
• Key is part of encryption information used to
  digitally sign rpm file

11
Using rpm to Manage Software Packages (continued)

• Fedora keys located in /usr/share/rhn
• --import imports keys into rpm database
• Check for keys
• rpm --checksig -v packagefilename

12
Converting RPM to DEB Packages

• sudo apt-get install alien
• Download rpm
• student18_at_student18-desktop sudo alien
  --scripts --to-deb avg75flm-r45-a0973.i386.rpm
  avg75flm_r45-1_i386.deb
• Coverts to deb generated
• Install Debian package
• student18_at_student18-desktop sudo dpkg --install
  avg75flm_r45-1_i386.deb

13
Repairing Package Manager

• sudo apt-get install -c
• Checks apt may need to be run if Synaptic
  package manager hangs
• sudo dpkg --configure -a
• Attempts to install all partially installed
  packages

14
APT Tools

• apt-get install package-name
• Installs a package
• apt-get remove package-name
• Removes a package
• --purge removes configuration files
• apt-cache search keyword
• Searches for packages that match a keyword

15
Updating the System Automatically

• Red Hat Network
• Download upgrades or security fixes for key
  operating system packages installed on system
• Subscribe to Red Hat Network service
• May be entitled to annual subscription as part of
  purchase
• Individuals can use for free

16
Updating the System Automatically (continued)

• Red Hat Network
• Uses icon on Panel in GNOME or KDE to indicate
  status
• Check mark in blue circle
• Flashing exclamation point in red circle
• To register, double-click network alert icon on
  panel
• To configure, right-click alert icon

17
Updating the System Automatically (continued)

• up2date utility
• Manage updated software
• Configure overall settings for Red Hat Network
• System Tools then Red Hat Network on GNOME main
  menu
• Tabs
• General
• Retrieval/installation
• Package exceptions

18
Software Updates in Ubuntu
19
Updating the System Automatically (continued)

• Management and provisioning products within Red
  Hat networks offering
• Must purchase
• Add capabilities to help keep systems secure and
  up to date

20
Understanding the File System

• During installation
• Partitions created
• ext3 or similar file system

21
Reviewing File System Types

• File system
• Collection of data structured in certain way so
  that it can be efficiently accessed
• Superblock
• Collection of information about file system as a
  whole meta data for file system
• Found in ext2 and ext3
• View superblocks
• sudo dumpe2fs /dev/hdd1 grep -i superblock

22
Reviewing File System Types (continued)

• ext2 and ext3 file systems
• Do not place files one after another filling up
  each area of hard disk in order
• Permit file to grow in size without being as
  likely to be broken into pieces
• Never need to defragment
• ext3
• Journaling file system

23
Reviewing File System Types (continued)

• Other journaling file systems
• ReiserFS
• Journaling File System (JFS)
• Virtual file system model
• Used by kernel
• Separates file system type from operation program
  wants to perform
• Linux can support any new file system type for
  which driver is available

24
Reviewing File System Types (continued)

• Each file system must be mounted
• Mount command
• Without any parameters
• List of currently mounted file systems

25
Checking File System Status

• Root file system becomes full
• Linux kernel can crash
• df command displays space usage information for
  each file system that is currently mounted
• If file system becomes full, must free space in
  directories where file system is mounted

26
df output

• Filesystem 1K-blocks Used
  Available Use Mounted on
• /dev/hdd1 8064524 3409880
  4244992 45 /
• varrun 517284 112
  517172 1 /var/run
• varlock 517284 4
  517280 1 /var/lock
• udev 517284 112
  517172 1 /dev
• devshm 517284 0
  517284 0 /dev/shm
• lrm 517284 18856
  498428 4 /lib/modules/2.6.15-23-386/volatile

27
Checking File System Status (continued)

• Immediately free space
• Look for large or numerous files in /tmp
  directory that can be deleted
• Look for large or numerous files in /var
  subdirectories
• Move system log file (/var/log/messages) to
  another file system that isnt as full
• See if any user subdirectories are using
  unusually large amounts of disk space
• Delete unused archive files

28
Checking File System Status (continued)

• du utility lists size of directory and all its
  subdirectories
• du h shows file sizes in kilobytes
• Various graphical tools and system administration
  scripts to check status of file systems
• Hardware Browser
• KDiskFree

29
File System Attributes

• ext3 file system assigns set of attributes to
  each file
• Not displayed by ls command
• lsattr command lists attributes of files in
  directory
• lsattr projectfile
• chattr command changes attributes of one or more
  files
• chattr i projectfile
• add attribute
• chattr -i projectfile
• remove attribute

30
Checking File Systems

• fsck utility
• Checks integrity of file systems
• Usually pronounced fizz-check
• Can also repair minor file system problems
• Must be run on file system that is not mounted
• Example fsck /dev/hda1
• e2fsck -c /dev/hda1
• e2fsck 1.38 (30-Jun-2005)
• /dev/hda1 is mounted.
• WARNING!!! Running e2fsck on a mounted
  filesystem may cause
• SEVERE filesystem damage.
• Do not run on a mounted volume.

31
Creating New File Systems

• Adding file system means
• Adding hard disk device to your system
• Making hard disk available to Linux by
• Formatting
• Mounting

32
Using the fdisk Utility

• Modifications to partition table only effective
  when you write changes to disk with w command to
  exit fdisk
• Example fdisk /dev/hdb

33
Using the fdisk Utility (continued)
34
Using the fdisk Utility (continued)

• Disk /dev/hdd 20.4 GB, 20490559488 bytes
• 255 heads, 63 sectors/track, 2491 cylinders
• Units cylinders of 16065 512 8225280 bytes
• Device Boot Start End Blocks
  Id System
• /dev/hdd1 1 1020
  8193118 83 Linux
• /dev/hdd2 1021 1151
  1052257 82 Linux swap / Solaris
• Command (m for help) n new partiion
• Command action
• e extended
• p primary partition (1-4)
• p - primary
• Partition number (1-4) 3
• First cylinder (1152-2491, default 1152)
• Using default value 1152
• Last cylinder or size or sizeM or sizeK
  (1152-2491, default 2491) 500

35
Using the fdisk Utility (continued)

• Command (m for help) t
• Partition number (1-4) 3
• Hex code (type L to list codes) l
• 0 Empty 1e Hidden W95 FAT1 80 Old
  Minix be Solaris boot
• 1 FAT12 24 NEC DOS 81 Minix
  / old Lin bf Solaris
• 2 XENIX root 39 Plan 9 82 Linux
  swap / So c1 DRDOS/sec (FAT-
• 3 XENIX usr 3c PartitionMagic 83 Linux
  c4 DRDOS/sec (FAT-
• 4 FAT16 lt32M 40 Venix 80286 84 OS/2
  hidden C c6 DRDOS/sec (FAT-
• 5 Extended 41 PPC PReP Boot 85 Linux
  extended c7 Syrinx
• 6 FAT16 42 SFS 86 NTFS
  volume set da Non-FS data
• 7 HPFS/NTFS 4d QNX4.x 87 NTFS
  volume set db CP/M / CTOS / .
• 8 AIX 4e QNX4.x 2nd part 88 Linux
  plaintext de Dell Utility
• 9 AIX bootable 4f QNX4.x 3rd part 8e Linux
  LVM df BootIt
• a OS/2 Boot Manag 50 OnTrack DM 93
  Amoeba e1 DOS access
• b W95 FAT32 51 OnTrack DM6 Aux 94
  Amoeba BBT e3 DOS R/O

36
Using the fdisk Utility (continued)

• c W95 FAT32 (LBA) 52 CP/M 9f
  BSD/OS e4 SpeedStor
• e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM
  Thinkpad hi eb BeOS fs
• f W95 Ext'd (LBA) 54 OnTrackDM6 a5
  FreeBSD ee EFI GPT
• 10 OPUS 55 EZ-Drive a6
  OpenBSD ef EFI (FAT-12/16/
• 11 Hidden FAT12 56 Golden Bow a7
  NeXTSTEP f0 Linux/PA-RISC b
• 12 Compaq diagnost 5c Priam Edisk a8
  Darwin UFS f1 SpeedStor
• 14 Hidden FAT16 lt3 61 SpeedStor a9
  NetBSD f4 SpeedStor
• 16 Hidden FAT16 63 GNU HURD or Sys ab
  Darwin boot f2 DOS secondary
• 17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI
  fs fd Linux raid auto
• 18 AST SmartSleep 65 Novell Netware b8 BSDI
  swap fe LANstep
• 1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot
  Wizard hid ff BBT
• 1c Hidden W95 FAT3 75 PC/IX
• Hex code (type L to list codes) 83
• write out parition
• Command (m for help) w

37
Formatting File Systems

• mke2fs command
• Formats partition
• Erasing all information on it
• Organizes space for data to be recorded
• Partition can be used by Linux
• Use -j option to add journaling
• For ext3
• Example mke2fs -j /dev/sdb2

38
Formatting File Systems (continued)

• fdformat /dev/fd0 command
• Format 3.5-inch disks
• tune2fs utility
• Examine superblock of file system
• Make minor changes to file system parameters
• tune2fs -j /dev/hdd convert to a journaling
  file system
• tune2fs /ddv/hdd -c maximum mount counts
• tune2fs /ddv/hdd -i daymonthweek frequency
• Time before running automatic system check before
  running automatic system check.

39
Mounting New File Systems

• mount command
• To access file system
• Indicate
• Device on which file system is stored
• Directory where file system should be made
  accessible in directory structure
• Example mount -t ext3 /dev/sdb2 /archive
• Specify type and mount point
• umount /dev/sdb2 command
• Unmounts the partition

40
Mounting New File Systems (continued)

• lostfound directory
• Placed in beginning of all new ext2 and ext3 file
  systems
• Indicates successful mounting
• File system cannot be in use when using umount
  command

41
Automating File System Mounting

• /etc/fstab configuration file
• Key to automounting file systems
• Contains one line for each file system to
  automount
• Add options when executing mount command
• Example mount -t ext3 -o defaults /dev/sdb2
  /archive

42
/etc/fstab

• /etc/fstab static file system information.
• ltfile systemgt ltmount pointgt lttypegt ltoptionsgt
  ltdumpgt ltpassgt
• proc /proc proc defaults
  0 0
• /dev/hdd1 / ext3
  defaults,usrquota,grpquota,errorsremount-ro 0
  1
• /dev/hdd2 none swap sw
  0 0
• /dev/hdc /media/cdrom0 udf,iso9660
  user,noauto 0 0
• /dev/fd0 /media/floppy auto
  rw,user,noauto 0 0
• ro read only, rw-read write
• user anyone may mount, nouser only root can
  mount
• Defaults rw,suid,dev,exec,auto,nouser,async
• auto mount automatically, noauto do not mount
  automatically

43
Using the autofs Mounting Service

• autofs service
• Daemon
• Watches for users to change to preconfigured
  directories
• Mounts needed file system in background
• Operated by script in /etc/rc.d/init.d directory
• /etc/auto.master lists directories to be
  automounted

44
Using the autofs Mounting Service (continued)

• autofs service
• Example
• Mounting /misc directory
• Create /etc/auto.misc file
• Contains options to use when autofs mounts file
  system to /misc

45
Managing Swap Space

• mkswap command
• Format partition set up using fdisk as swap space
• Example mkswap /dev/hda2
• swapon command activates swap space

46
Setting Quotas on Disk Usage

• Disk quotas
• Limit on amount of hard disk space user or group
  can use
• Steps to create quota
• Enable quotas on file system
• Establish quota for users or groups
• Activate quota system
• Review current disk usage for file system

47
Setting Quotas on Disk Usage (continued)

• ulimit command
• Part of bash shell
• Impose limits on actions of users

48
Setting Quotas on Disk Usage (continued)

• sudo apt-get install quota
• Add usrquota and grpquota to partition that must
  have quotas
• /dev/hdd1 / ext3
  defaults,usrquota,grpquota,errorsremount-ro 0
  1
• sudo init 1 single user mode
• sudo mount / -o remount,rw
• remount to update options
• quotacheck -mavug
• quotaon /
• sudo touch /quota.user
• sudo touch /quota.group
• quotaon /dev/hdd1

49
Quota Commands

• quota check quota for current users
• quotaon /mountpointname turn on quotas
• repquota report on quota utilization
• edquota u username set quota for user
• edqupta u t set grace period

50
Using Networked File Systems

• Many Linux networks use networked file systems to
  share data transparently over network
• Use mount command to make directory on another
  computer appear as part of local file system
• Similar to idea of mapping a network drive in
  Microsoft Windows

51
Using Networked File Systems (continued)

• Networked file systems normally accessed using
• Network file system (NFS)
• sudo apt-get install nfs
• Server message block (SMB)

52
Using Networked File Systems

• gedit /etc/exports
• /home/localfoldertoshare remote_host_ip(permission
  s)
• Specify who can access the localfoldertoshare and
  what their permissions will be
• gedit /etc/hosts.allow
• specifies services that remote host can use
• portmapremote_host_ip
• lockdremote_host_ip
• mountdremote_host_ip
• rquotadremote_host_ip
• statdremote_host_ip
• /etc/hosts.deny
• Deny all other hosts access to services
• ALLALL

53
Using Networked File Systems

• remote_host_ip
• 192.168.240.100 single ip address
• all addresses
• 192.168.240.0/24 subnet
• Permissions
• ro read only, rw-read write
• root-squash no remote root level access to file
  system
• async,sync how files are updated asynchronously
  or synchronously