disk information and format

It is quote common that you need information about disk. There are many commands (sometimes distribution depended) that can do that. Try following:

lshw -class disk
smartctl -i /dev/sda
hdparm -i /dev/sda
hwinfo --disk
ls /dev/disk/by-id
cat /proc/partitions

cat /proc/mdstat




To add new disk you just need

fdisk -l

parted /dev/sdb

(parted) mklabel GPT                                                      

(parted) mkpart primary 0% 100%                                           

(parted) quit

mkfs.ext4 /dev/sdb1

tune2fs -m 0 /dev/sdb1

Add line to /etc/fstab

identify problem

If something does not work first look at logs :
cat /var/log/syslog
dmesg

But there are not only these logs (see /var/log folder).

For hardware identify what was determined :
lsusb
lspci
lshal
lshw

There you easily find vendor or identification for hardware.

For software (run by command) try:
strace command


or use verbose output of command, often by:
command --verbose



For open files, see:
lsof

Mentioned utilities have many options, so try arguments. Use keywords from previous outputs to feed goog..

playing with linear raid and ext4

The goal is to create linear raid with ext4 array from 4 disks. Than add 5. disk and verify data.

Create linear raid from 4 disks
$ sudo mdadm -v --create /dev/md0 -l linear -n 4 /dev/sdb /dev/sdc /dev/sdd /dev/sde

Make ext4fs
$ sudo mkfs.ext4 /dev/md0

Mount array
$ sudo mkdir array
$ sudo mount /dev/md0 /media/array

Information about array
$ sudo mdadm --detail /dev/md0
$ cat /proc/mdstat

Set the system recognize the raid after the reboot
$ sudo echo 'DEVICES /dev/sdb /dev/sdc /dev/sdd /dev/sde' >> /etc/mdadm/mdadm.conf
$ sudo mdadm --detail --scan >> /etc/mdadm.conf

Upload test data, make md5 checksum
$ cd /media/array/
$ wget http://cdimage.debian.org/debian-cd/5.0.7/amd64/iso-cd/debian-507-amd64-netinst.iso
$ md5sum debian-507-amd64-netinst.iso
971ddace926fc3f7765f595da5cce223 debian-507-amd64-netinst.iso

Add 5. disk and resize filesystem
$ mdadm --grow --add /dev/md0 /dev/sdf
$ sudo resize2fs /dev/md0

Add device at /etc/mdadm/mdadm.conf and rescan (change list line)

Compare checksum
$ md5sum debian-507-amd64-netinst.iso
971ddace926fc3f7765f595da5cce223 debian-507-amd64-netinst.iso

Checksums are the same.

Add line to /etc/fstab and test reboot.

Sometimes there are problems with assemble, look in

cat /proc/mdstat


if there are not some dummy traits from one disk, that you can stop by

mdadm --stop /dev/md_d0


See also wiki

esxi managing from console

See also: Robert Chase page

It is easy to use console of ESXi server and do some managing from it.


Get all virtual machines
vim-cmd vmsvc/getallvms

Power off/on/reboot virtual machine with id 368
vim-cmd vmsvc/power.off 368
vim-cmd vmsvc/power.on 368
vim-cmd vmsvc/power.reboot 368

Get information about virtual machine with id 368
vim-cmd vmsvc/get.summary 368

Delete all snapshots
vim-cmd vmsvc/snapshot.removeall 368

Refresh datastore
esxcfg-nas -r

Delete and add nfs datastore back
esxcfg-nas -d back
esxcfg-nas -a back --host IPADDRESS --share DIRECTORY

Running processes
esxtop

Console screen
dcui

apache2 modules

List of loaded modules:
apache2ctl -t -D DUMP_MODULES

List of compiled modules:
apache2 -l

Apache2 version:
apache2 -v

Disable module:
a2dismod module_name

Enable module:
a2enmod module_name

second postfix instance with auth smtp

See advosys.ca help.ubuntu.com adomas.org postfix.org

Copy config dir
cp -rp /etc/postfix /etc/postfix-out

Create file /etc/postfix-out/sasl/smtpd.conf with
pwcheck_method: saslauthd
mech_list: PLAIN LOGIN
Note, that previous plaintext mechanism send credentials unencrypted. Therefore TLS-encrypted SMTP session is used.

Add following lines to /etc/postfix-out/main.cf
queue_directory = /var/spool/postfix-out
data_directory = /var/lib/postfix-out

Create and copy queue and data directories
mkdir /var/spool/postfix-out
postfix -c /etc/postfix-out check
cp -rp /var/lib/postfix /var/lib/postfix-out
cp -rp /var/spool/postfix/etc /var/spool/postfix-out
cp -rp /var/spool/postfix/usr /var/spool/postfix-out
cp -rp /var/spool/postfix/lib /var/spool/postfix-out

Add following line to /etc/postfix/main.cf
alternate_config_directories = /etc/postfix-out

Modify port no. for smtp at /etc/postfix-out/master.cf

1025 inet n - - - - smtpd

Test start
postfix -c /etc/postfix-out start

Install sasl and mkdir var folder
apt-get install libsasl2-2 sasl2-bin


Modify /etc/init.d/saslauthd
PIDFILE=/var/spool/postfix-out/var/run/saslauthd/saslauthd.pid

Modify /etc/default/saslauthd
START=yes
PWDIR="/var/spool/postfix-out/var/run/saslauthd"
PARAMS="-m ${PWDIR}"
PIDFILE="${PWDIR}/saslauthd.pid"
OPTIONS="-c -m /var/spool/postfix-out/var/run/saslauthd"

Create dirs for sasl in chroot postfix
dpkg-statoverride --force --update --add root sasl 755 /var/spool/postfix-out/var/run/saslauthd

Add following lines to /etc/postfix-out/main.cf
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_path = smtpd

Restart all services
/etc/init.d/saslauthd restart
/etc/init.d/postfix restart
postfix -c /etc/postfix-out stop
postfix -c /etc/postfix-out start


Test by sasl
testsaslauthd -u USERNAME -p PASSWORD -f /var/spool/postfix-out/var/run/saslauthd/mux

Test by telnet
telnet SERVER_ADDRESS 1025
Trying IPADDRESS...
Connected to SERVER_NAME.
Escape character is '^]'.
220 SERVERNAME ESMTP Postfix (Ubuntu)
ehlo localhost
250-SERVERNAME
250-PIPELINING
250-SIZE 10240000
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN


Create startup script
cp /etc/init.d/postfix /etc/init.d/postfix-out

And replace pairs in new file
/etc/postfix by /etc/postfix-out
postfix by postfix -c /etc/postfix-out
/var/spool/postfix by /var/spool/postfix-out
postconf by postconf -c /etc/postfix-out

Now make symlinks in rc.d to /etc/init.d/postfix-out, e.g.
ln -s /etc/init.d/postfix-out /etc/rc6.d/K01postfix-out

Font Arial in R

See stat.ethz.ch

Install fonts

sudo apt-get install ubuntu-restricted-extras


In console

ttf2afm /usr/share/fonts/msttcorefonts/arial.ttf > ~/afont/arial.afm
ttf2afm /usr/share/fonts/msttcorefonts/ariali.ttf > ~/afont/ariali.afm
ttf2afm /usr/share/fonts/msttcorefonts/arialbd.ttf > ~/afont/arialbd.afm
ttf2afm /usr/share/fonts/msttcorefonts/arialbi.ttf > ~/afont/arialbi.afm

In R

postscript("fa1x.eps",
family=c("/home/pvl/afont/arial.afm","/home/pvl/afont/arialbd.afm","/home/pvl/afont/ariali.afm","/home/pvl/afont/arialbi.afm"),
horizontal=FALSE, height=4.5, width=7.5, paper = "special", pointsize=4)