Category: Computers & Technology

reset root password in mysql

DBS” wrote:

> I have a problem, It’s been months since I used MySQL and (I believe) I had

> set it up with a root password. Now I can’t log on to MySQL as root MySQL

> user and create a new user or manage an existing user (I can log onto server

Familiar situation. :)

Do so:

service mysql stop

wait until MySQL shuts down. Then run

mysqld_safe –skip-grant-tables &

then you will be able to login as root with no password.

mysql -uroot mysql

In MySQL command line prompt issue the following command:

UPDATE user SET password=PASSWORD(“abcd”) WHERE user=”root”;

FLUSH PRIVILEGES;

At this time your root password is reset to “abcd” and MySQL will now

know the privileges and you’ll be able to login with your new password:

mysql -uroot -pabcd mysql

How to get tcpdump from Virtual Switches in ESX 3

1) Install VMware-esx-supptools-3.0.0-1.i386.rpm from the ESX 3 cd.

2) You can then run “/usr/lib/vmware/support/esxnet-support man” and learn how to use the tool, but …

3) To get a trace from the portgroup, you’ll need to run:

/usr/lib/vmware/support/esxnet-support trace -z -p Network0

Network0 of course will need to change to your portgroup name.

Another thing you can do is create a portgroup and put it in promiscuous mode. Then, run tcpdump in that guest that’s in that portgroup.

How to install VMware Tools in Trustix Secure Linux

How to install VMware Tools

This is taken from: http://www.trustix.net/wiki/index.php/VMwareTools

How to install VMware Tools

This has (so far) only been verified to work on VMware Workstation v5.5 and a TSL 3.0 installation with the following groups installed: “Minimal with SSH”, “Commonly used local utilities” and “Commonly used network utilities”; a typical, almost minimal, TSL system.

Required packages

You need the following packages installed on the system to get VMware Tools to compile the needed modules (other packages may be installed due to dependencies):

make
gcc
glibc-devel
kernel-source

All in one using swup:

swup --install make gcc kernel-source glibc-devel

n.b. –ignore-filter may be required on TSL 2.2 to allow kernel-source to be installed.

Configure kernel-source

VMware tools won’t compile if you have not configured and prepared the kernel-source.

  • The kernel-source installs itself in /usr/src/kernel-source-<version>. You should link this folder to /usr/src/linux:
cd /usr/src
ln -s kernel-source-<version> linux

We also need to copy the kernel config file into our kernel-source:

cp /boot/config-<version> /usr/src/linux/.config
  • Lets prepare the kernel-source for VMware Tools:
cd /usr/src/linux
make oldconfig
make modules_prepare

n.b. With TSL 2.2 use ‘make dep’ in place of ‘make modules_prepare’.

Install VMware Tools

Having your TSL 3.0 installation active, release the lock (CTRL+ALT) and go to the menu and choose:

VM -> Install VMware Tools..

Mount the virtual CD-ROM containing the VMware tools and install the rpm there. Then unmount it.

mount /mnt/cdrom
rpm -Uhv /mnt/cdrom/VMwareTools-<version>-i386.rpm
umount /mnt/cdrom

Compile and configure VMware modules for TSL

To finish the VMware Tools installation we run the VMware tools configure script and it will compile the VMware Tools modules:

vmware-config-tools.pl

Answer yes to all questions and all but the X Windows display driver is configured. See below for X Window driver support.

Optimized network driver – VMXnet

When TSL 3.0 was installed as guest OS it found and installed the pcnet32 driver. You could stick with it, but I would recommend you change it for the optimized vmxnet driver which was just compiled. The following instructions are displayed after vmware-config-tools.pl finish to help you replace the network driver:

service network stop
rmmod pcnet32
rmmod vxnet
vi /etc/modprobe.conf /etc/mkinitrd/modules <-- change vmnics to vmxnet
tsl-fixboot.sh --install <kernel-version>
depmod -a
modprobe vmxnet
service network start

X Window

You need the following packages installed to have the X Window driver compile (other packages may download and install due to dependencies):

xorg-x11
xorg-x11-devel

As always, you may install them all in one using swup:

swup --install xorg-x11 xorg-x11-devel

Now run vmware-config-tools.pl again to compile the svga driver:

vmware-config-tools.pl

NB! You may get a warning about not being able to compile the vmxnet driver. Just ignore that. You already have it installed if you followed the instructions above.

Please note, this will only give you a minimalistic xorg-x11 without gnome or another DE/WM. I would recommend you check out the Desktop Environment section to get a fully working and useful desktop.

If you get the error when compiling the tool: “The kernel defined by this directory of header files does not have the same address space size as your running kernel.”

The way I fixed it was just by using a newer version of VMware-tools. I used the source from ESX 3.0 and you can search on the web and you should be able to find it.

How to Set Up DNS Blacklisting in a Lab Environment for Test

This is a very simple setup for those who have a lab environment where they do not want to be connected to the public Internet while doing the testing.

Some background:

The way dnsbl works is that when a connection is made to your mail server, it will take the client’s IP address, reverse it, append a domain onto it, and do a dns A or TXT record lookup for that name.

For example, if a spammer’s IP is 10.4.17.108, and you are using spam.list.com as your dnsbl site, your MTA will do a query for 108.17.4.10.spam.list.com. If the query returns positive, it means that the IP address is listed in the blackhole list and that mail should be rejected.

So the first thing you will need to do is set up a simple dns server. You can find out how to do that by consulting the DNS & Bind book or http://docs.sun.com/db/doc/816-7511 or various other sources.

Then, you need to set up a zone. Here's a sample:
 
# cat /var/named/spam.list.com
 
$TTL 86400 
@ 1D IN SOA @ root (
  42 ; serial
 3H ; refresh
 15M ; retry
 1W ; expiry
 1D ) ; minimum
NS localhost.
 A 10.4.16.11
108.17.4.10 IN A 127.0.0.2
108.17.4.10 IN TXT "10.4.17.108 is listed in spam.list.com"

With this in tact, all you need to do is set up your MTA to use spam.list.com for dnsbl calls.

lost vmfs volume – says 100% available – SAN LUN, storage pr

1) fdisk -l

this would show which device doesn’t have a partition.

2) dd if=/dev/sd(x) of=/tmp/dump_sdx.txt count=100 bs=1024

file /tmp/dump_sdx.txt shows x86 boot sector.

strings /tmp/dump_sdx.txt shows some vmdk files

3) fdisk -lu /dev/sd(x) shows that there are no partitions on the disk.

4) ran fdisk /dev/sd(x). created new partition spanning entire lun and then used partition type fb.

5) run “vmkfstools -V”

That’s it

Synchronizing with time server: [FAILED]

ntpd: Synchronizing with time server: [FAILED]
Starting ntpd: [ OK ]

When does it do the sync?

# Synchronize with servers if step-tickers exists

# or the -x option is used
echo -n $”$prog: Synchronizing with time server: ”
/usr/sbin/ntpdate $dropstr -s -b -p 8 $tickers 2>/dev/null >/dev/null
RETVAL=$?
[ $RETVAL -eq 0 ] && success || failure It does the sync when the /etc/ntp/step-tickers file is there. [root@localhost ~]#

cat /etc/ntp/step-tickers
time.vmware.com

Why would this happen? Strange stuff…

[root@localhost ~]# /etc/init.d/ntpd stop
Shutting down ntpd: [ OK ]
[root@localhost ~]# ntpdate time.vmware.com
28 Jun 10:49:44 ntpdate[25663]: step time server 10.16.12.148 offset 90.895171 sec

The ntpdate command doesn’t fail … wonder why… tail /var/log/messages shows:
Jun 28 10:52:31 localhost ntpd: ntpd shutdown failed
un 28 10:52:31 localhost ntpdate[26038]: can’t find host time.vmware.com
Jun 28 10:52:31 localhost ntpdate[26038]: no servers can be used, exiting
Jun 28 10:52:31 localhost ntpd: failed
Jun 28 10:52:31 localhost ntpd[26043]: ntpd [email protected] Wed Nov 17 15:43:55 EST 2004 (1)
Jun 28 10:52:32 localhost ntpd: ntpd startup succeeded

Can’t find host? Why’s that? Let’s try using the IP address instead of the name in the step-tickers file. Well, the IP address fixes it in Redhat Enterprise Linux 4, but I had this problem with ESX server (based on Redhat 7.2).

The problem was
[root@localhost ~]# file /etc/ntp/step-tickers
/etc/ntp/step-tickers: ASCII text, with CRLF line terminators The file was a DOS file. When the problem was in ESX, I was able to see the ^M character in /var/log/messages, so I was able to fix it after finding that. Fun stuff huh?

Interesting time issue …

Interesting Time issue in Linux.<-->

To complicate things a little, this was Redhat Enterprise Linux 4 update 2 in a VMware VM – reason why it makes it a little more complicated is because that there’s a time problem for Virtual Machines – in virtualization, you can’t afford to give the clock ticks that the older 2.6 kernels ask for (default 1000HZ). You can read more on it here: http://www.vmware.com/vmtn/resources/238.

So in this case, virtualization wasn’t the problem.

Here’s where I started:

ln -sf /usr/share/zoneinfo/America/Chicago /etc/localtime

date

Mon Feb 13 18:25:28 UTC 2006

ls -ld /etc/localtime

lrwxrwxrwx 1 root root 35 Feb 13 18:25 /etc/localtime -> /usr/share/zoneinfo/America/Chicago

cat /etc/sysconfig/clock

ZONE=”America/Chicago”

UTC=false

ARC=false

run hwclock – it just gives you the prompt back.

date -s “Feb 13 20:25:28 PST 2006”

run date and get

Mon Feb 13 04:25:28 UTC 2006

run setup – go through the options set it to America/Chicago and still … UTC … why!?

set:

export TZ=America/chicago

still … date shows UTC!

reboot the Vm, go into the bios … same thing …. why!!??

zdump -v America/Chicago … shows a bunch of bullshit – nothing that helps.

finally:

rpm -qf /usr/share/zoneinfo/America/Chicago

rpm –verify tzdata-2004e-2

S.5….T. /usr/share/zoneinfo/America/Chicago

S.5….T. /usr/share/zoneinfo/CST6CDT

S.5….T. /usr/share/zoneinfo/SystemV/CST6CDT

S.5….T. /usr/share/zoneinfo/US/Central

ahh … wonder how the files got changed. Anyways, it doesn’t matter.

reinstalled rpm

rpm –force -Uvh tzdata-2004e-2.noarch.rpm

Now run:

ln -sf /usr/share/zoneinfo/America/Chicago /etc/localtime

Now the date’s okay … cool deal!

mysql commands – create database / set permissions

/usr/bin/mysqladmin -u root password ‘new-password’
/usr/bin/mysqladmin -u root -h chunli.shocknetwork.com password ‘new-password’

mysql -u root -p -e “create database <dbname>”
mysql -u root -p -e “grant all on <dbname>.* to <user>@localhost identified by ‘<password>'”