Additional Information On AIX System Administration – IV

# lsfs command gives the following output:

Hd1 – home

Hd2 – USR

HD3 – TMP

HD4 – Root

HD5 – BLV

HD6 – Paging Space (2 types: primary, secondary)

HD7 – Not Found

HD8 – JFS

HD9 – VAR

HD10 – MNT

HD11 – admin (available in AIX V 6.1)

LED code 0c0 means successful completion of dump.

To view extended permissions, command used is:

# ls –e <filename>

Command used to set tty port for bidirectional mode:

# share <port attributes>

Commands used to setup quota for file system for end users are:

# vi /etc/<file system>

# edquota /<file system> <username>

# quotaon <file system>

# quotaon /<file system>

To initiate system dump, command used is:

# sysdumpstart –P (for primary)

# sysdumpstart –S (for secondary)

SNAP is generally used to gather system information.

Some of the SNAP commands are:

# snap –a

# snap –g

# snap –D

Image.data contains information about VG’s and LV’s.

Bosinst.data contains information about installation flow control.

To view mksysb tape and to restore particular file from mksysb tape, commands used are:

# tctl –f /dev/<tape drive name>

# restore –tvf /dev/<tape drive name>

# restore –xvf /dev/<tape drive name>

For eg:

# tctl –f /dev/rmt0

# restore – tvf /dev/rmt0

# restore – xvf /dev/rmt0

Tctl command is basically used to rewind the tape drive.

To list NIM objects, command used:

# lsnim

NIM stands for network installation management.

To see NIM log, command used is:

# nim –o showlog –a full_log = yes –a log_type = logtype NIMclient

Logtype can be boot, script etc.

NIMClient is the hostname / ip address of the client machine.

Sources of this command : IBM AIX Forum

# smit system command is used to change the server time.

# smit date command is used to change system date.

Time synchronization is either done by running time demon or ntp demon.

P5 family:

1. Entry :

i.      P5 510

ii.      P5 520

iii.      P5 550

1. Mind Range :

i.      P5 570

1. High End :

i.      P5 575

ii.      P5 590

iii.      P5 595

Physical Volume (PV) id can be found in Cuat ODM class.

Device in defined state means there is an entry in ODM class CuDV.

Procedure to change bootlist from hdisk0 to hdisk1:

Go to SMS mode by pressing F1 and change the bootlist by running the following command:

# bootlist –m normal hdisk0 hdisk1

If a machine keeps rebooting and repeating POST, it means either there is invalid bootlist or corrupted BLV or hardware failure of boot device.

More we will discuss about AIX System Administration in the coming posts.

Till then,

Happy Learning !

System Backup And Restore Commands in AIX

System Backup has become an essential part in today’s world. Backup is generally created to prevent loss of data.

In various production environments, backup of data is created to save all the transactions and the history of vital information available inside servers in each and every company today.

This particular post will discuss about the various commands used with respect to system backup and restore in AIX Operating system in a production environment.

There are multiple commands available to take Backup and restore it back on to the servers.

The first command that we will discuss is:

MKSYSB Command: This command is used to create an image on the Operating System on the Tape Drive.

This backup created on the tape drive can be used later to restore the entire OS from the tape onto the disk in its original state. It works very similar to how backup and restore works in windows Operating Systems (OS).

Command used to create backup with mksysb command is:

# mksysb –ief /dev/rmt0

Where rmt0 is the name of the tape drive on which the backup is created.

Flags:

Flag i stands for the image backup that will be created on running this command

E stands for exclusion of the file systems which are not needed while creating the backup on the tape drive. Administrator can remove the files/file systems they think is not needed while creating a backup.

To remove a particular file system, admin needs to edit the /etc/excludevg.rootvg file and specify the file systems which need not be backed up.

F stands for reading out the files backed up.

Mksysb command is also used to backup SMIT screen.

Commands used to backup user information are:

1. Savevg command: this command finds and backup all the files that belongs to a particular Volume group (VG).

Command used to create backup is:

# savevg –ief /dev/rmt0 <vgname>

Where vgname is the name of the volume group to be backed up.

Similarly, to backup a non root vg, command use is:

# savevg –f <destination path> -i <non root vg files to be backed up>

For eg:

#savevg –f /home/user01/vg00_backup –i vg00

After running this command, admin can remove vg00 from the system. Command to restore vg00 back from vg00_backup is:

# restvg –qf <backup file path> <folder where the data is to be restored>

For eg:

# restvg –qf /home/user01/vg00_backup hdisk10

So restvg command is basically used to restore non root vg data.

1. Tar command: it writes data from the disk onto the archival medium. It also restores the data back from tape to the disc.

To backup current working directory, command used is:

# cd /<current working directory>

# pwd

used to verify the current working directory.

# tar –cvf /dev/rmt0

Where

C stands to create a new backup on the archival medium

V stands for verbose

F stands for read

# tar –x extracts files from the archival medium on to the disk.

# tar –t will list the order in which the files appear on the archival medium.

To backup using tar command:

# tar –cvf <path where backup is taken / archival medium> <file system to be backed up>

To restore:

# tar –xvf <archival medium path>

1.  Cpio command: copies files into / out of the storage (archival) medium.

2. Backup command: creates the image/ copy of the files to be backedup on the archival medium.

# backup [–i] or [-p] or [-v] or [-q] or [-u] flags can be used to take backup.

-u flag creates an entry in /etc/dumpdates that is having all the backup history information.

To backup current directory, command used is:

#cd <current working directory>

# pwd

# backup –i –f /dev/rmt0

To backup a particular file system, command used is:

# backup -0 –f <path where the data is to be backed up> -f <files to be backed up>

For eg:

# backup -0 –f /home/user01/vg00_backup –i /home/usr01/vglv

Flag 0 means weekly backup

1 means daily

To restore this backup command used is:

# restore –qf <path of archival medium>

Or

# restore –xvf <path of archival medium>

Generally, /dev/rmt0 is the default destination medium where data is backed up.

Condition for RootVg Backup:

1.       Concentrate only on rootvg

2.      Unmounted file systems are not backed up

3.      Contains VGDA information, PV, VG and Policies

Restoration in maintenance mode is done in 3 ways:

1.       Boot from CD

2.       Telinit S|s|M|m

3.       # shutdown -m

There are 2 ways to restore after logging into maintenance mode:

1.       System backup first and then restore (offline mode)

2.       Restore directly from tape drive (all devices are shown CD0, RMT0. Choose tape drive / cd drive. Choose hard disk where restoration is to be done. System is restored)

/etc file system will hold most of the information about backup and restore.

P.S: Most of the information written on this blog and in every post is inspired and written after reading and going through various redhat pdfs and ibm books.