Category: IT

While you can just create a pv out of raw block device I normally try to avoid it as it can cause confusion as to what the block device is being used for. It may also break some of the auto discover routines that LVM can use if it’s missing it’s configuration files.

Here’s an example of using parted to create a GPT with 1 partition that is the whole drive and set the partition flag to be lvm. The mkpart requires that you specify a file system but it doesn’t create the file system. Seems to be a long standing bug in parted. Also the start offset of 1M is to ensure that you get proper alignment.

parted /dev/sdb
mklabel GPT
mkpart primary ext2 1M 100%
set 1 lvm on
quit
pvcreate /dev/sdb1
pvdisplay
vgcreate vg_*name* /dev/sdb1 /dev/sdc1 /dev/sdd1
vgdisplay
lvcreate –extents 100%FREE -n lv_*name* vg_*name*
lvdisplay
mkfs.xfs -f /dev/mapper/vg_*name*-lv_*name*
df -ah

yum shell
remove sysklogd
install rsyslog
run
exit

vi /etc/rsyslog.conf
paste in the below:
# ### begin forwarding rule ###
# The statement between the begin … end define a SINGLE forwarding
# rule. They belong together, do NOT split them. If you create multiple
# forwarding rules, duplicate the whole block!
# Remote Logging (we use TCP for reliable delivery)
#
# An on-disk queue is created for this action. If the remote host is
# down, messages are spooled to disk and sent when it is up again.
$WorkDirectory /var/lib/rsyslog # where to place spool files
$ActionQueueFileName fwdRule1 # unique name prefix for spool files
$ActionQueueMaxDiskSpace 1g # 1gb space limit (use as much as possible)
$ActionQueueSaveOnShutdown on # save messages to disk on shutdown
$ActionQueueType LinkedList # run asynchronously
$ActionResumeRetryCount -1 # infinite retries if host is down
# remote host is: name/ip:port, e.g. 192.168.0.1:514, port optional
*.* @@your splunk server:514
# ### end of the forwarding rule ###

chkconfig rsyslog on
service rsyslog restart

So we were having this weird latency issue with our new R815’s and the Broadcomm nics utilizing iSCSI on a segregated lan.

Turns out we needed the BCM-NetXtremeII-5.0-offline_bundle-940344.zip driver imported into update manager, a reboot later, we were all happy!

This explains how to add a cron job to VMware in such a way that it will still be there after reboots.

Having enabled ssh access to your ESX/ESXi server, ssh in as root.

First, add the cron job to the root crontab:

1. Edit /var/spool/cron/crontabs/root
2. Add the line (all on one line)
5 0 * * * /full/path/to/script arguments/with/full/path > /full/path/to/logfile 2>&1
3. When you quit, use Esc, :wq! to override the read only attribute.

For details of the meaning of “5 0 * * *” (5 minutes past midnight every day) read the man page for crontab(5) on any Unix/Linux server, or else on the web.

Now, add a command to /etc/rc.local to re-generate the cron job when ESX/ESXi reboots

1. Edit /etc/rc.local, using a command such as “vi /etc/rc.local”.
2. At the end of the file, add 3 lines (using “G” then “O” in vi). The first kills crond, the second adds the new cron job to the root crontab file, ad the third restarts crond:
/bin/kill $(cat /var/run/crond.pid)
/bin/echo ’5 0 * * * /full/path/to/script arguments/with/full/path > /full/path/to/logfile 2>&1′ >> /var/spool/cron/crontabs/root
/bin/busybox crond
3. Save and exit the editor (Press the “Esc” key then “:wq” then press “Return” in vi)
4. Run the command “auto-backup.sh” so that the change to /etc/rc.local survives a reboot.

Every time you change the cron job, remember to update /etc/rc.local as well and run the “auto-backup.sh” command to backup the new /etc/rc.local file.

Open the Apache configuration file located at /etc/httpd/conf/httpd.conf
Change AllowOverride None to AllowOverride All inside the DocumentRoot Directory Directive, normally
This is very important for wordpress post name permalinks!!!

Install MySQL and Apache

yum install mysql
yum install mysql-server
chkconfig mysqld on
service mysqld start
sudo yum install php-gd
yum install httpd
chkconfig httpd on
service httpd start

Create Database:

mysql

Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 5340 to server version: 3.23.54

Type ‘help;’ or ‘h’ for help. Type ‘c’ to clear the buffer.

mysql> CREATE DATABASE databasename;
Query OK, 1 row affected (0.00 sec)

mysql> GRANT ALL PRIVILEGES ON databasename.* TO “username”@”hostname”
-> IDENTIFIED BY “password”;
Query OK, 0 rows affected (0.00 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)

mysql> EXIT
Bye
$

# ### begin forwarding rule ###
# The statement between the begin … end define a SINGLE forwarding
# rule. They belong together, do NOT split them. If you create multiple
# forwarding rules, duplicate the whole block!
# Remote Logging (we use TCP for reliable delivery)
#
# An on-disk queue is created for this action. If the remote host is
# down, messages are spooled to disk and sent when it is up again.
$WorkDirectory /var/lib/rsyslog # where to place spool files
$ActionQueueFileName fwdRule1 # unique name prefix for spool files
$ActionQueueMaxDiskSpace 1g # 1gb space limit (use as much as possible)
$ActionQueueSaveOnShutdown on # save messages to disk on shutdown
$ActionQueueType LinkedList # run asynchronously
$ActionResumeRetryCount -1 # infinite retries if host is down
# remote host is: name/ip:port, e.g. 192.168.0.1:514, port optional
*.* @@splunk:514