Thursday, November 22, 2012

Configuring an NTP server without internet access (locally)

Is the first time I had to figure out how to configure an NTP (Network Time Protocol) server without internet access... most of the time you just configure your /etc/ntp.conf file to point to a public NTP server and your internal servers to point to this one acting as your server and you are done. Nothing interesting there... 

First make sure you have ntp package installed in all your servers

rpm -qa |grep ntp-4
Make sure your firewall is stopped 

service iptables stop
service ip6tables stop
chkconfig  iptables off
chkconfig ip6tables off

Or add the required rules to allow port 123 between your servers

iptables -A RH-Firewall-1-INPUT -m state --state NEW -m udp -p udp --dport 123 -j ACCEPT
iptables -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 123 -j ACCEPT
service iptables save
service iptables restart

Backup your current configuration file in all the servers... (just in case)

cp /etc/ntp.conf /etc/ntp.conf.orig

Basically you have to configure your server pointing to itself so it will be in sync... something like this...

vi /etc/ntp.conf
fudge stratum 10

Notice that to access its own system clock, also called the local clock , NTP uses the pseudo IP address This IP address must not be mixed up with, which is the IP of the localhost or loopback

Here you may want to restrict the IPs that are allowed but since this is assuming you are on a local (controlled) environment with no internet access then is not absolutely necessary

Restart the ntpd server

/etc/init.d/ntpd restart
service ntpd restart

On the client side you configure as follows...

vi /etc/ntp.conf

Where the server IP is the IP of your NTP server 

Restart the ntpd server on the clients too

/etc/init.d/ntpd restart
service ntpd restart

To Verify your network mask you can look at your network script

cat /etc/sysconfig/network-scripts/ifcfg-eth0

Ensure NTP will start at boot in all the servers

chkconfig ntpd on

Synchronize your local time with the server (do it 3 times):

ntpdate -u [your ntp server IP]

Determining if the NTP is synchronized properly

ntpq –p

One of the problems that I found was with the Stratum Value as you can see in the configuration file we set it to 10 you can verify the current value on the ntp server with the following command 

ntpq -c rv

Now... what does that mean... 

NTP increases the stratum for each level in the hierarchy a NTP server pulling time from a "stratum 1" server would advertise itself as "stratum 2" to its clients. A stratum value of "16" is reserved for unsynchronized servers meaning that your internal NTP server thinks not to have a reliable timesource in other words is not synchronizing to a higher-level stratum server 

Most of the time take like 15 minutes to lower the value... if you are at 16 you wont be able to sync the clients... Once dropped try again

If you need to do some debugging there look at the output of ntpq peers for clues for possible reasons

Thursday, November 8, 2012

Portmir using screen

For those AIX lovers that have by destiny the need to play with Linux and cry because in Linux there is nothing like portmir... where there is a *like solution for this... screen... if you don´t know what screen is look at my previous post ... but here is how to configure it to share a session... 

As root:
   1. Set the screen binary setuid root.
       sudo chmod +s /usr/bin/screen
       sudo chmod 755 /var/run/screen
   2. Start screen
       screen -S portmir
   3. Verify the username with w
   4. Allow multiuser access in the screen session
       :multiuser on
   5. Grant permission to the remote user to access the session
       :acladd username
   6. The remote user can now connect to the session using
       screen -x root/portmir


Screen as you may already know is a tool to handle multiple sessions in one window... very useful to remove load from your personal laptop.. avoid having to connect everyday to all those sessions... and having the capability to left processes running =D ... 

well on Linux most of the time is already installed on AIX is never so install it... but there is a little issue on the code that need to be fixed to successfully install the tool on AIX... 

Download the tool from...
cd aix/freeSoftware/aixtoolbox/RPMS/ppc/wget
get wget-1.9-2.aix5.1.ppc.rpm
rpm -hUv wget-1.9-2.aix5.1.ppc.rpm
rpm -hUv screen-3.9.10-2.aix4.3.ppc.rpm
gunzip screen-4.0.3.tar.gz
tar -xvf screen-4.0.3.tar
cd screen-4.0.3
vi misc.c

changed following part in order to get over it:

,----[ misc.c - original part ]
| #else /* USESETENV */
| # if defined(linux) || defined(__convex__) || (BSD >= 199103)
| )
| setenv(var, value, 1);
| # else
| setenv(var, value);
| # endif /* linux || convex || BSD >= 199103 */
| #endif /* USESETENV */
| }

Then I used the dirty hack by adding ", 1" to the second setenv-statement directly.

,----[ misc.c - altered part ]
| #else /* USESETENV */
| # if defined(linux) || defined(__convex__) || (BSD >= 199103) ||
| setenv(var, value, 1);
| # else
| setenv(var, value, 1);
| # endif /* linux || convex || BSD >= 199103 */
| #endif /* USESETENV */
| }

That "solved" the error-message above.

make install

Now that the tool is installed here some useful commands

Access to the screen command line...
Jump with ID
List open consoles
ScrollBack” (ESC to finish)
detached (will appear the word [detached])
retach (If there are many open session will appear the list, just select the ID to open Type "screen [-d] -r [pid.]" to resume one of them.”
set password
open new terminal
rename the current session
screen –x
share a screened session without detaching
kill session
Terminate session
enable multiuser mode

Now to have a very nice .screenrc just copy paste the following and add your servers

autodetach on # Autodetach session on hangup instead of terminating screen completely
startup_message off # Turn off the splash screen
defscrollback 30000 # Use a 30000-line scrollback buffer
scrollback 30000
termcapinfo xterm ti@:te@
vbell off # turn off visual bell
caption string "%?%F%{= Bk}%? %C%A %D %d-%m-%Y %{= kB} %t%= %?%F%{= Bk}%:%{= wk}%? %n "
hardstatus alwayslastline
#hardstatus string '%{= kG}[ %{G}%H %{g}][%= %{= kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B} %d/%m %{W}%c %{g}]'
hardstatus string '%{= kG}[ %{R}%t %{g}]%= %{g}[%{B} %d/%m %{W}%c %{g}]'

screen -t prod-a ssh prod-a
screen -t prod-b ssh prod-b
screen -t prod-c ssh prod-c
screen -t prod-d ssh prod-d

that will create a nice screen and launch all the servers and if you have SSH trusted keys automatically connect to all of them ;) and look sort of like this

 and if you hit [ ctrl+a "  ] you will be able to select your server from there 

A simple Throughtput test using SCP

In the past it was easy to execute a throughput test using ftp now on modern environment FTP or Telnet y most of the time not allowed so we have to do our best with SCP, SFTP and SSH for security reasons... well... having a good test on your environment from all servers to all servers and keeping that info handy can be userful when you are experiencing low performance on the network 

Lets say you have servers A B and C you will execute your test as follows
A to B  
A to C
B to C

that will cover pretty much all the possibilities and you can run B to A but since you already have A to B and they go thru the same wire ... what is the point?... your chooise

   Step # 1: Create a large file (1 GB)

      dd if=/dev/zero of=/tmp/big.file bs=1024M count=1
      1+0 records in
      1+0 records out
      1073741824 bytes (1.1 GB) copied, 1.88378 seconds, 570 MB/s

   Step # 2: Use scp to transfer file
      scp -v /tmp/big.file
   Step # 3 From the end of the output capture only the required information and build your table

Source Destination MB/s  Duration
A         B                 47.7    0.2 Seconds

Next time you have a problem... well run the test there and figure how slow you are comparing against your baseline =)

ldapsearch over SSL

Recently I found with an issue with some ldap latency between a WAS server and an ldap farm having to do several hops to get there I needed to find out if the connection was working and also how long where they taking... running tcpdump or wireshark traces help but does not give you a real view of how ldap is working ... so I decided to configure ldapclient in this server and do some testing... and this might not work the same in all the environment but will be a good guide. 

First install ldapclient in my case running on RHEL I also needed the openldap package to be installed once this is completed you are able to execute the ldapsearch command... 

But that will be pretty much enough for a regular environment but in my case I had to go thru SSL using port 636 (secure) instead of 389 (insecure) so you have to do a modification to the /etc/openldap/ldap.conf file and add the following lines... 

PORT 636

Easy huh? now if you wonder how can you get the certificate to be used... well use this command

echo -n | openssl s_client -connect :636 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > ldapserver.pem

now how can I check what is being accepted for search in the ldap server... at least

ldapsearch -x -H ldaps:// -b "" 

and you will receive a line sort of like this 

uniquemember: uid=########,c=us,ou=ldapserver,

so now you can narrow your search as follows to look for us folks

ldapsearch -x -H ldaps:// -b "c=us,ou=ldapserver," 

and then you go to webpshere console and look for those fields that we can access as 

and now you can look by mail, cn, and uid as follows 

ldapsearch -x -H ldaps:// -b "c=us,ou=ldapserver," ""

Now to check the response times use the following... 

while true
/usr/bin/time -f "\t%e" 2>> /tmp/ldapresponse.out ldapsearch -x -H ldaps:// -b "c=us,ou=ldapserver," "" > /dev/null

Thursday, October 4, 2012

Using alt_disk_copy


Most system administrators have experienced the following scenario:
  • A failed ML upgrade.
  • It's getting to the end of the day.
  • You cannot fix it.
  • It's too late to get it resolved by third-party support.
  • You need to back out.
Typically, this situation requires a rootvg restore, whether it uses a tape mksysb restore or a network boot restore. There is no doubt it is a pain! Using the alt_disk_copy method to take a copy of your rootvg only requires the time it takes to do a reboot to recover your rootvg to the pre-upgrade event. This article demonstrates how to implement alt_disk_copy when applying an AIX upgrade and how to recover rootvg. alt_disk_copy can also be used for testing two different versions of AIX. You simply upgrade one disk then boot off it, and when you need to go back to the other version, simply boot off that disk instead. Indeed, the alt_disk_copy is often used to clone the rootvg to a spare disk for regular on-line backup of rootvg. It can also be used as a hardware migration tool of rootvg.

This article focuses on a typical rootvg two-disk software mirror set-up. However, alt_disk_copy is not restricted to this two-disk set-up; the same principles apply to multiple software mirroring situations.

The alt_disk utilities consist of the following commands:
  • alt_disk_copy performs disk cloning.
  • alt_rootvg_op performs maintenance operations on the clone rootvg.
  • alt_disk_mysysb performs a mksysb copy.
This demonstration does not discuss alt_disk_mysysb.

The filesets required for the alt commands are:

Overview information

Because the alt_disk_copy command takes a copy of the current running rootvg to another disk, be sure to have all the file systems mounted that you want cloned across. alt_disk_copy only copies the currently mounted file systems in rootvg. There is no need to stop processes to execute alt_disk_copy; however, this process can take some time, so it is best to do it at lunchtime or in the evening (remember it is taking a running copy). Once the copy has completed, you will be presented with two rootvg volume groups:

where altinst_rootvg is the cloned non-active/varied off rootvg. The cloned rootvg has all its logical volumes prefixed with the name 'alt'. The boot list is also changed to boot off altinst_rootvg. AIX likes to do things like this; it assumes you will want to boot off the cloned and not the real rootvg. If the system is now rebooted and when the system comes back up, the original rootvg will become:

The original altinst_rootvg becomes:

If you decide to reboot off the old_rootvg, when the system comes back up, the old_rootvg becomes:

The rootvg becomes:

Do not worry about the renaming of the original and cloned rootvg. I will demonstrate this shortly.

With a successful completion of an upgrade, the disk containing the cloned rootvg can then be destroyed using the alt_rootvg_op and mirrored back in. If the upgrade event has gone disastrously, there is no real problem--simply take a snapshot for third-party support, then boot off the good rootvg. For users to log in, it is business as normal.

When you get a response back from support on the fix, during off-line hours, simply reboot off the cloned rootvg and fix the issue. There is no need to go through the time-consuming tasks of re-applying the upgrade because you already have it on the cloned rootvg. Get the upgrade tested, and if it is all OK, destroy the cloned rootvg and mirror back in.

Do not use importvg or exportvg on the clone rootvg; use the alt commands instead.

With the cloned rootvg, you can mount the file systems by waking up the disk using alt_rootvg_op. Doing whatever works is required on the cloned file systems, and one would assume here to fix a patch of link, or gather information for third-party support, then put the disk back to sleep, which will also unmount the file systems.

Excluding directories when cloning

When cloning, you can exclude certain directories by creating the file: /etc/exclude.rootvg. The entries should start with the ^ /. characters. The '^' means to search for the string at the beginning of the line and the './' means relative to the current directory. You are advised to do this so alt_disk_copy does not misinterpret the command, as it uses grep to search for the string. So, make sure you provide the full pathname, prefixed with '^.' , for example, to exclude the following directories:

I could insert into the /etc/exclude.rootvg file:

Make sure there are no empty lines after the last entry.

Let's get cloned!

Let's now go through a typical clone. Assume you have a software two-disk (hdisk0 and hdisk1) mirror of rootvg, and further assume that you are going to do a ML (or application upgrade, assuming it is installed in rootvg) upgrade on this system. I will demonstrate one way this can be done to clone the disk and after a successful upgrade will bring the disk back into rootvg and re-mirror. I will also demonstrate the actions you can take if the upgrade fails.


Before unmirroring the rootvg, first take some time to ensure you are correctly mirrored and have no stale LV's, because if you do, the unmirrorvg will fail. Of course, you could always do a migratepv to move the missing LV's across if the unmirrorvg fails. A simple method to check that you are mirroring is to issue the command:
lsvg -l rootvg

For each row of data output, check that the output of the PPs column is double that of the LPs column.

Another method to check to see if you are mirroring is to use: lspv -l and compare the output to make sure you have entries for each LV on both disks.

Next, issue the bosboot command. I personally always do this prior to either rebooting or disk operations involving rootvg; it is a good habit to have:
# bosboot -a
bosboot: Boot image is 35803 512 byte blocks.

A listing of the disks being used for this demonstration is as follows:
# lspv
hdisk0          0041a97b0622ef7f                    rootvg          active
hdisk1          00452f0b2b1ec84c                   rootvg          active

Next, unmirror rootvg and take the disk that is going to be used for cloning out of rootvg. This demonstration uses hdisk1 to clone rootvg, so issue the unmirrorvg command:
# unmirrorvg rootvg hdisk1
0516-1246 rmlvcopy: If hd5 is the boot logical volume, please run 'chpv -c name>'
       as root user to clear the boot record and avoid a potential boot
       off an old boot image that may reside on the disk from which this
       logical volume is moved/removed.
0516-1804 chvg: The quorum change takes effect immediately.
0516-1144 unmirrorvg: rootvg successfully unmirrored, user should perform
       bosboot of system to reinitialize boot records.  Then, user must modify
       bootlist to just include:  hdisk0.

Next, take hdisk1 out of rootvg in readiness for the cloning:
# reducevg rootvg hdisk1

Confirm that the disk is now not assigned to any volume groups:
# lspv
hdisk0          0041a97b0622ef7f                    rootvg          active
hdisk1          00452f0b2b1ec84c                    None

Running alt_disk_copy

Now you are ready to issue the alt_disk_copy. Simply supply hdisk1 as a parameter to the command. The basic format is:
alt_disk_copy -d

To use an exclude list, the basic format is:
alt_disk_copy -e /etc/exclude.rootvg -d

The following output from the alt_disk_copy command has been truncated:
# alt_disk_copy -d hdisk1
Calling mkszfile to create new / file.
Checking disk sizes.
Creating cloned rootvg volume group and associated logical volumes.
Creating logical volume alt_hd5
Creating logical volume alt_hd6
Creating logical volume alt_hd8
Creating logical volume alt_hd4
Creating logical volume alt_hd2
Creating logical volume alt_hd9var
Creating logical volume alt_hd3
Creating logical volume alt_hd1
Creating logical volume alt_hd10opt
Creating /alt_inst/ file system.
Creating /alt_inst/home file system.
Creating /alt_inst/opt file system.
Creating /alt_inst/tmp file system.
for backup and restore into the alternate file system...
Backing-up the rootvg files and restoring them to the
alternate file system...
Modifying ODM on cloned disk.
Building boot image on cloned disk.
forced unmount of /alt_inst/var
forced unmount of /alt_inst/usr
forced unmount of /alt_inst/tmp
forced unmount of /alt_inst/opt
forced unmount of /alt_inst/home
Changing logical volume names in volume group descriptor area.
Fixing LV control blocks...
Fixing file system superblocks...
Bootlist is set to the boot disk: hdisk1

At this stage, you now have a cloned rootvg called altinst_rootvg. Notice in the previous output alt_disk_copy has changed the bootlist to boot off the cloned rootvg, which is now hdisk1.
# lspv
hdisk0          0041a97b0622ef7f                    rootvg          active
hdisk1          00452f0b2b1ec84c                    altinst_rootvg

This can be confirmed by issuing the bootlist command:
# bootlist -m normal -o
hdisk1 blv=hd5

At this point the ML upgrade can now be installed. After an ML upgrade you will need to reboot the system. For this demonstration, the ML upgrade will be installed on the real rootvg (that is hdisk0), so you need to change the bootlist now, because you want the system to come up with the new upgrade running.
# bootlist -m normal hdisk0

Confirm the change of the bootlist:
# bootlist -m normal -o
hdisk0 blv=hd5

Next, install the ML upgrade, then reboot. After rebooting, the system presents the following rootvg and cloned rootvg. As can be seen, no root volume group has been renamed, because we booted off the real rootvg (hdisk0):
# lspv
hdisk0          0041a97b0622ef7f                    rootvg          active
hdisk1          00452f0b2b1ec84c                    altinst_rootvg

Next let's assume everything has gone OK on the upgrade and support users and the systems administrator has signed it off with no issues found. The alt_disk_copy can now be destroyed, and the disk brought back into rootvg for mirroring. Use the alt_rootvg_op command with the X parameter to destroy the cloned rootvg. The basic format is:
alt_rootvg_op -X < cloned rootvg to destroy>

# alt_rootvg_op -X altinst_rootvg
Bootlist is set to the boot disk: hdisk0

Next, extend rootvg to bring hdisk1, and then mirror up the disk:
# extendvg -f rootvg hdisk1
# mirrorvg rootvg hdisk1
0516-1804 chvg: The quorum change takes effect immediately.
0516-1126 mirrorvg: rootvg successfully mirrored, user should perform
       bosboot of system to initialize boot records.  Then, user must modify
       bootlist to include:  hdisk0 hdisk1.

Change the bootlist to include both disks and run bosboot:
# bootlist -m normal -o hdisk0 hdisk1
hdisk0 blv=hd5
# bosboot -a
bosboot: Boot image is 35803 512 byte blocks.
# bootlist -m normal -o
hdisk0 blv=hd5
hdisk1 blv=hd5

For this demonstration, that's it: mission accomplished. The pgrade is installed with no issues. The system is operational. That's pretty much how alt_disk_copy works if all goes OK. But what if the upgrade fails? What options do you have? Let's look at that next.

Recovery positions, please

Let's now assume you have just installed the ML upgrade and rebooted, and issues have been found with the operational running of AIX. Remember, you currently have the disks in the following state:
# lspv
hdisk0          0041a97b0622ef7f                    rootvg          active
hdisk1          00452f0b2b1ec84c                    altinst_rootvg

At this point, a snapshot should be taken of the running system, in readiness for third-party support, for the call that you will undoubtedly log. Taking stock of the current situation, you have:
  • rootvg: with post-upgrade issues.
  • altinst_rootvg : with good copy pre-upgrade.
Take me back

To get back to the pre-upgrade, simply change the bootlist to boot off the (altinst_rootvg) hdisk1, then reboot. It's that simple:
# bootlist -m normal -o hdisk1
hdisk1 blv=hd5
# bootlist -m normal -o
hdisk1 blv=hd5
# shutdown -Fr

After the reboot, you will be presented with the following rootvg disks:
# lspv
hdisk0          0041a97b0622ef7f                    old_rootvg
hdisk1          00452f0b2b1ec84c                    rootvg          active

Next, issue a bosboot and confirm the bootlist:
# bosboot -a
bosboot: Boot image is 35803 512 byte blocks.
# bootlist -m normal -o
hdisk1 blv=hd5

The system is now back to the pre-upgrade state.

Post upgrade fixing

At a convenient time schedule that is agreed-upon with the end users, and with information provided by third-party support, you can then boot off the ML failed upgraded disk (hdisk0) and apply a fix that might solve the issue, so change the bootlist to boot off (old_rootvg) hdisk0 and reboot:
# bootlist -m normal -o hdisk0
# shutdown -Fr

After the reboot, in readiness to apply the fix, you will be presented with the following rootvg disks:
# lspv
hdisk0          0041a97b0622ef7f                    rootvg          active
hdisk1          00452f0b2b1ec84c                    altinst_rootvg

Next, apply the fix or instructions on how to fix it have been carried out, and assume the system is now operational again.

After the system has been tested and signed off bring in hdisk1, use the commands described earlier:
alt_rootvg_op -X altinst_rootvg

Bootlist is set to the boot disk: hdisk0
# extendvg -f rootvg hdisk1
# mirrorvg rootvg hdisk1
bootlist -m normal -o hdisk0 hdisk1
hdisk0 blv=hd5
# bosboot -a

bosboot: Boot image is 35803 512 byte blocks.
#  bootlist -m normal -o
hdisk0 blv=hd5
hdisk1 blv=hd5
# lspv
hdisk0          0041a97b0622ef7f                    rootvg          active
hdisk1          00452f0b2b1ec84c                    rootvg          active

Waking the disk up

Within a cloned rootvg environment, you can wake up the cloned rootvg to be active. All cloned file systems from the cloned rootvg will be mounted. It is quite useful because you have a good running system, but at the same time mount the file systems from the cloned rootvg for further investigation or file modification. When a cloned rootvg is woken up, it is renamed to:

Do not issue a reboot while the cloned rootvg filesystems are still mounted, because unexpected results can occur. You can also rename a cloned rootvg, which is useful when you have more than one cloned rootvg.

Assume you have the disks in the following state:
# lspv
hdisk0          0041a97b0622ef7f                    old_rootvg
hdisk1          00452f0b2b1ec84c                    rootvg          active

To wake up a disk, the basic format is:
alt_rootvg_op -W -d < hdisk>

Let's now wake up old_rootvg (hdisk0):
# alt_rootvg_op -W -d hdisk0
Waking up old_rootvg volume group ...

Checking the state of the disks, you can see the old_rootvg has been renamed to altinst_rootvg and is now active.
# lspv
hdisk0          0041a97b0622ef7f                    altinst_rootvg  active
hdisk1          00452f0b2b1ec84c                    rootvg          active

The cloned file systems have been mounted, with the prefix of /alt_:
# df -m
Filesystem    MB blocks      Free %Used    Iused %Iused Mounted on
/dev/hd4         128.00    102.31   21%     2659    11% /
/dev/hd2        1968.00    111.64   95%    40407    58% /usr
/dev/hd9var      112.00     77.82   31%      485     3% /var
/dev/hd3          96.00     69.88   28%      330     3% /tmp
/dev/hd1         208.00    118.27   44%     1987     7% /home
/proc                 -         -    -         -     -  /proc
/dev/hd10opt    1712.00   1445.83   16%     6984     3% /opt
/dev/alt_hd4     128.00    102.16   21%     2645    11% /alt_inst
/dev/alt_hd1     208.00     33.64   84%     1987    21% /alt_inst/home
/dev/alt_hd10opt   1712.00   1445.77   16%     6984     3% /alt_inst/opt
/dev/alt_hd3      96.00     72.38   25%      335     2% /alt_inst/tmp
/dev/alt_hd2    1968.00    100.32   95%    40407    59% /alt_inst/usr
/dev/alt_hd9var    112.00     77.53   31%      477     3% /alt_inst/var

At this point file modification or further investigation can be carried out on the cloned rootvg. Now you can access the cloned file systems. Once these tasks have been carried out, put the cloned rootvg to sleep and in the same operation issue a bosboot on that disk. The basic format of the command is:
alt_rootvg_op -S -t

Let's now put the altinst_rootvg to sleep:
# alt_rootvg_op -S -t hdisk0
Putting volume group altinst_rootvg to sleep ...
Building boot image on cloned disk.
forced unmount of /alt_inst/var
forced unmount of /alt_inst/usr
forced unmount of /alt_inst/tmp
forced unmount of /alt_inst/opt
forced unmount of /alt_inst/home
forced unmount of /alt_inst
forced unmount of /alt_inst
Fixing LV control blocks...
Fixing file system superblocks...

The current state of the disks is now:
# lspv
hdisk0          0041a97b0622ef7f                    altinst_rootvg
hdisk1          00452f0b2b1ec84c                    rootvg          active

From the above demonstration, you can see the cloned rootvg name stayed the same: altinst_rootvg.
It is sometimes good to go back to the original state of the disks to save confusion, especially if you have more than one cloned disk. So rename altinst_rootvg back to old_rootvg. The basic format is:
alt_rootvg_op -v -d

So in this example, you would issue:
# alt_rootvg_op -v old_rootvg -d hdisk0
# lspv
hdisk0          0041a97b0622ef7f                    old_rootvg
hdisk1          00452f0b2b1ec84c                    rootvg          active

Of course, you could rename the cloned rootvg to something more meaningful, if so desired.
# alt_rootvg_op -v bad_rootvg -d hdisk0
bash-2.05a# lspv
hdisk0          0041a97b0622ef7f                    bad_rootvg
hdisk1          00452f0b2b1ec84c                    rootvg          active

You cannot rename a cloned rootvg to altinst_rootvg; it is a reserved name.

From this point, the system is now operational or not, depending on the success of the fix, using the commands described earlier.

If the fix worked on (old_rootvg) hdisk0, then run with the new ML version.

Confirm that the disk will boot off hdisk0:
# bootlist -m normal -o hdisk0

# shutdown -Fr

Destroy the newly cloned disk (we rebooted off old_rootvg; it now becomes altinst_rootvg) hdisk1:
# alt_rootvg_op -X altinst_rootvg

Bring in hdisk1 into rootvg for mirroring:
# extendvg -f rootvg hdisk1
# mirrorvg rootvg hdisk1
# bosboot -a
# bootlist -m normal -o hdisk0 hdisk1

If the fix did not work, then stay at the same ML version, and fix another day:
Confirm that the disk will boot off hdisk1:
# bootlist -m normal -o hdisk1

Destroy cloned disk (old_rootvg) hdisk0:
# alt_rootvg_op -X old_rootvg

Bring in hdisk0 into rootvg for mirroring:

# extendvg -f rootvg hdisk0
# mirrorvg rootvg hdisk0
# bosboot -a
# bootlist -m normal -o hdisk0 hdisk1


alt_disk_copy           Clones the currently running system to an alternate disk
  1. To clone the running 5300-00 rootvg to hdisk3, then apply updates from /updates to bring the cloned rootvg to a 5300-01 level:
  2.    alt_disk_copy -d hdisk3 -F 5300-01_AIX_ML -l /updates
  3. The bootlist would then be set to boot from hdisk3 at the next reboot.
  4. To clone the running rootvg to hdisk3 and hdisk4, and execute update_all on all updates from /updates:
  5.    alt_disk_copy -d "hdisk3 hdisk4" -b update_all -l /updates
  6. The bootlist would then be set to boot from hdisk3 at the next reboot.
  7. To clone the running rootvg to hdisk1 and stop after phase 1:
  8.   alt_disk_copy -d hdisk1 -P1
  9. To execute phases 2 and 3 on an existing alternate rootvg and reboot the system on successful completion:
  10.  alt_disk_copy -d hdisk1 -P23 -r
  11. To clone the running system to hdisk1 and hdisk2, and to convert the file systems from JFS file systems to JFS2 file systems, run the following command:
  12. alt_disk_copy -B -T -d hdisk1 hdisk2
  13. Attention:
  14. Do not change the bootlist to use the cloned rootvg.
alt_disk_mksysb      Installs an alternate disk with a mksysb install base install image.

  1. To install a mksysb image on hdisk3 and hdisk4 , then run a customized script (/tmp/script) to copy some user files over to the alternate rootvg file systems before reboot:
  2.    alt_disk_mksysb -m /mksysb_images/my_mksysb -d "hdisk3 hdisk4" -s /tmp/script
  3. To install a mksysb image on hdisk2 and stop after phase 1:
  4.    alt_disk_mksysb -m /mksysb_images/my_mksysb -d hdisk2 -P1
  5. To execute phases 2 and 3 on an existing alternate rootvg on hdisk4 and reboot the system upon successful completion:
  6.    alt_disk_mksysb -d hdisk4 -m /mksysb_images/my_mksysb -P23 -r
  7. To install a mksysb image on hdisk1, and to convert the file system from a JFS file system to a JFS2 file system, run the following command:
  8. alt_disk_mksysb -B -T -m  /mksysb_images/my_mksysb -d hdisk1
  9. Attention:
  10. Do not change the bootlist to use the cloned rootvg.

alt_rootvg_op           Performs operations on existing alternate rootvg volume groups.
  1. To remove the original rootvg ODM database entry, after booting from the new alternate disk, enter the following command:
  2. alt_rootvg_op -X old_rootvg
  3. To cleanup the current alternate disk install operation, enter the following command:
  4. alt_rootvg_op -X
  5. To determine the boot disk for a volume group with multiple physical volume, enter the following command:
  6. alt_rootvg_op -q -d hdisk0
  7. Illustrated Example
  8. # lspv

  9. hdisk0          00006091aef8b687     old_rootvg
  10. hdisk1          00076443210a72ea     rootvg
  11. hdisk2          0000875f48998649     old_rootvg

  12. # alt_rootvg_op -q -d hdisk0

  13. hdisk2
  14. To modify an alt_disk_install volume group name, enter the following command:
  15. alt_rootvg_op -v alt_disk_530 -d hdisk2
  16. Illustrated Example
  17. # lspv

  18. hdisk0          00006091aef8b687     rootvg
  19. hdisk1          00000103000d1a78     rootvg
  20. hdisk2          000040445043d9f3     altinst_rootvg
  21. hdisk3          00076443210a72ea     altinst_rootvg
  22. hdisk4          0000875f48998649     None
  23. hdisk5          000005317c58000e     None

  24. # alt_rootvg_op -v alt_disk_432 -d hdisk2

  25. #lspv

  26. hdisk0          00006091aef8b687     rootvg
  27. hdisk1          00000103000d1a78     rootvg
  28. hdisk2          000040445043d9f3     alt_disk_432
  29. hdisk3          00076443210a72ea     alt_disk_432
  30. hdisk4          0000875f48998649     None
  31. hdisk5          000005317c58000e     None
  32. To "wake up" an original rootvg after booting from the new alternate disk, enter the following command:
  33. alt_rootvg_op -W -d hdisk0
  34. To "put to sleep" a volume group that had experienced a "wake-up" and rebuild the boot image, enter the following command:
  35. alt_rootvg_op -S -t
  36. To update the active alternate rootvg to the latest fileset levels available in /updates and install them into the alternate root volume group, enter the following command:
  37. alt_rootvg_op -C -b update_all -l /updates