How do I improve my server disk performance

Posted on August 16, 2012June 4, 2015 by coder

From http://www.ubuntu.com

server runs rsnapshot multiple times a day to backup remote hosts. The actual incremental backup part takes very little time. The significant time is spent doing things like:-

/bin/cp -al /srv/rsnapshot/hourly.0 /srv/rsnapshot/hourly.1

Which takes about 2 hours. I realise there are a bazillion tiny files in there.

$ sudo du -hs hourly.1
659G hourly.1

1 2	$ sudo du -hs hourly.1 659G hourly.1

Also when rsnapshot deletes an old backup this can take a long time:-

/bin/rm -rf /srv/rsnapshot/daily.6/

Which takes about half an hour.

My questions are as follows, configuration of server and some IO stats are detailed below. I can of course provide more debug info if necessary:-

How can I identify where the bottlenecks are?

Am I reaching the limits of what’s capable (IO wise) with this box?

Are there any performance tweaks I could make?

Should I use a different RAID level?

Would it make sense to swap two of the internal RAID disks (half of each mirror) with two ‘other halves of the other mirror’ on the external array?

Note: I’m somewhat not inclined to be doing things like compiling my own kernel. Ideally I’d like to stick on 10.04 LTS, unless there’s some magic in later versions that makes this all work a lot quicker.

Internally the server has 1x160GB SATA boot disk and 4x2TB disks:-

Disk /dev/sde: 160.0 GB, 160041885696 bytes
Disk /dev/sdf: 2000.4 GB, 2000398934016 bytes
Disk /dev/sdh: 2000.4 GB, 2000398934016 bytes
Disk /dev/sdi: 2000.4 GB, 2000398934016 bytes
Disk /dev/sdg: 2000.4 GB, 2000398934016 bytes

Disk /dev/sde: 160.0 GB, 160041885696 bytes

Disk /dev/sdf: 2000.4 GB, 2000398934016 bytes

Disk /dev/sdh: 2000.4 GB, 2000398934016 bytes

Disk /dev/sdi: 2000.4 GB, 2000398934016 bytes

Disk /dev/sdg: 2000.4 GB, 2000398934016 bytes

The four internal 2TB disks are in a software MD RAID10 setup:-

md0 : active raid10 sdg1[3] sdh1[0] sdi1[2] sdf1[1]
3907023872 blocks 64K chunks 2 near-copies [4/4] [UUUU]
Additionally I have an external EDGE10 drive enclosure which is connected via a PCI-E eSATA card and contains four more drives of 500GB:-

Disk /dev/sda: 500.1 GB, 500107862016 bytes
Disk /dev/sdb: 500.1 GB, 500107862016 bytes
Disk /dev/sdc: 500.1 GB, 500107862016 bytes
Disk /dev/sdd: 500.1 GB, 500107862016 bytes
This is also setup as an MD RAID10 array

md1 : active raid10 sdb1[1] sda1[0] sdd1[3] sdc1[2]
976767872 blocks 64K chunks 2 near-copies [4/4] [UUUU]
md0 and md1 are combined to make one big LVM. Note: I only recently added the external array, so it's pretty much blank, I don't think there are any blocks on it right now.

This is presented as an LVM volume:-

--- Logical volume ---
LV Name /dev/data/data
VG Name data
LV UUID amZCgU-sQLi-R363-dUFx-Bcdf-iwlt-ZNnDp8
LV Write Access read/write
LV Status available
# open 1
LV Size 4.54 TiB
Current LE 1190134
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 512
Block device 251:0
Which is formatted as EXT4 and mounted as /srv:-

/dev/mapper/data-data on /srv type ext4 (rw)
There's plenty of free space.

/dev/mapper/data-data
4.5T 2.2T 2.1T 51% /srv
Other information that might be useful:-

$ uname -a
Linux ubuntuserver 2.6.32-32-server #62-Ubuntu SMP Wed Apr 20 22:07:43 UTC 2011 x86_64 GNU/Linux
.

00:11.0 SATA controller: ATI Technologies Inc SB700/SB800 SATA Controller [AHCI mode] (rev 40)
02:00.0 RAID bus controller: Silicon Image, Inc. SiI 3132 Serial ATA Raid II Controller (rev 01)
When doing the cp command during rsnapshot I see the following in iostat:-

avg-cpu: %user %nice %system %iowait %steal %idle
0.55 0.00 5.47 66.14 0.00 27.85

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sde 0.00 0.00 0.10 0.00 0.80 0.00 8.00 0.00 0.00 0.00 0.00
sdf 0.00 407.50 0.00 66.80 0.00 3790.40 56.74 124.86 1524.88 13.55 90.50
sdh 0.00 406.90 0.00 66.90 0.00 3790.40 56.66 92.89 1230.52 13.21 88.40
sdi 0.00 407.80 5.50 70.20 44.00 3824.00 51.10 113.83 1333.84 12.34 93.40
sdg 0.00 406.80 6.10 71.60 48.80 3827.20 49.88 64.32 787.68 11.69 90.80
md0 0.00 0.00 11.50 1484.60 92.00 11876.80 8.00 0.00 0.00 0.00 0.00
dm-0 0.00 0.00 11.50 1484.70 92.00 11877.60 8.00 5331.18 471.91 0.63 94.70
md1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
So basically lots of writes, plenty of IO wait.

So right now the box is idle, I have suspended all jobs.

avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.00 0.00 0.00 100.00

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sde 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdf 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdh 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdi 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
sdg 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
md1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
dm-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Looks peachy!

$ sudo hdparm -T -t /dev/sd[a-i]

/dev/sda:
Timing cached reads: 2532 MB in 2.00 seconds = 1265.95 MB/sec
Timing buffered disk reads: 270 MB in 3.02 seconds = 89.53 MB/sec

/dev/sdb:
Timing cached reads: 2516 MB in 2.00 seconds = 1258.07 MB/sec
Timing buffered disk reads: 264 MB in 3.02 seconds = 87.37 MB/sec

/dev/sdc:
Timing cached reads: 2442 MB in 2.00 seconds = 1220.80 MB/sec
Timing buffered disk reads: 272 MB in 3.00 seconds = 90.60 MB/sec

/dev/sdd:
Timing cached reads: 2520 MB in 2.00 seconds = 1259.64 MB/sec
Timing buffered disk reads: 272 MB in 3.02 seconds = 90.07 MB/sec

/dev/sde:
Timing cached reads: 2524 MB in 2.00 seconds = 1261.48 MB/sec
Timing buffered disk reads: 306 MB in 3.01 seconds = 101.56 MB/sec

/dev/sdf:
Timing cached reads: 2366 MB in 2.00 seconds = 1183.28 MB/sec
Timing buffered disk reads: 388 MB in 3.01 seconds = 128.88 MB/sec

/dev/sdg:
Timing cached reads: 2536 MB in 2.00 seconds = 1267.52 MB/sec
Timing buffered disk reads: 400 MB in 3.00 seconds = 133.12 MB/sec

/dev/sdh:
Timing cached reads: 2538 MB in 2.00 seconds = 1269.08 MB/sec
Timing buffered disk reads: 426 MB in 3.00 seconds = 141.90 MB/sec

/dev/sdi:
Timing cached reads: 2538 MB in 2.00 seconds = 1268.57 MB/sec
Timing buffered disk reads: 402 MB in 3.01 seconds = 133.69 MB/sec

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

md0 : active raid10 sdg1[3] sdh1[0] sdi1[2] sdf1[1]

3907023872 blocks 64K chunks 2 near-copies [4/4] [UUUU]

Additionally I have an external EDGE10 drive enclosure which is connected via a PCI-E eSATA card and contains four more drives of 500GB:-

Disk /dev/sda: 500.1 GB, 500107862016 bytes

Disk /dev/sdb: 500.1 GB, 500107862016 bytes

Disk /dev/sdc: 500.1 GB, 500107862016 bytes

Disk /dev/sdd: 500.1 GB, 500107862016 bytes

This is also setup as an MD RAID10 array

md1 : active raid10 sdb1[1] sda1[0] sdd1[3] sdc1[2]

976767872 blocks 64K chunks 2 near-copies [4/4] [UUUU]

md0 and md1 are combined to make one big LVM. Note: I only recently added the external array, so it's pretty much blank, I don't think there are any blocks on it right now.

This is presented as an LVM volume:-

--- Logical volume ---

LV Name /dev/data/data

VG Name data

LV UUID amZCgU-sQLi-R363-dUFx-Bcdf-iwlt-ZNnDp8

LV Write Access read/write

LV Status available

# open 1

LV Size 4.54 TiB

Current LE 1190134

Segments 2

Allocation inherit

Read ahead sectors auto

- currently set to 512

Block device 251:0

Which is formatted as EXT4 and mounted as /srv:-

/dev/mapper/data-data on /srv type ext4 (rw)

There's plenty of free space.

/dev/mapper/data-data

4.5T 2.2T 2.1T 51% /srv

Other information that might be useful:-

$ uname -a

Linux ubuntuserver 2.6.32-32-server #62-Ubuntu SMP Wed Apr 20 22:07:43 UTC 2011 x86_64 GNU/Linux

00:11.0 SATA controller: ATI Technologies Inc SB700/SB800 SATA Controller [AHCI mode] (rev 40)

02:00.0 RAID bus controller: Silicon Image, Inc. SiI 3132 Serial ATA Raid II Controller (rev 01)

When doing the cp command during rsnapshot I see the following in iostat:-

avg-cpu: %user %nice %system %iowait %steal %idle

0.55 0.00 5.47 66.14 0.00 27.85

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util

sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sde 0.00 0.00 0.10 0.00 0.80 0.00 8.00 0.00 0.00 0.00 0.00

sdf 0.00 407.50 0.00 66.80 0.00 3790.40 56.74 124.86 1524.88 13.55 90.50

sdh 0.00 406.90 0.00 66.90 0.00 3790.40 56.66 92.89 1230.52 13.21 88.40

sdi 0.00 407.80 5.50 70.20 44.00 3824.00 51.10 113.83 1333.84 12.34 93.40

sdg 0.00 406.80 6.10 71.60 48.80 3827.20 49.88 64.32 787.68 11.69 90.80

md0 0.00 0.00 11.50 1484.60 92.00 11876.80 8.00 0.00 0.00 0.00 0.00

dm-0 0.00 0.00 11.50 1484.70 92.00 11877.60 8.00 5331.18 471.91 0.63 94.70

md1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

So basically lots of writes, plenty of IO wait.

So right now the box is idle, I have suspended all jobs.

avg-cpu: %user %nice %system %iowait %steal %idle

0.00 0.00 0.00 0.00 0.00 100.00

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util

sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sde 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdf 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdh 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdi 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

sdg 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

md1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

dm-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Looks peachy!

$ sudo hdparm -T -t /dev/sd[a-i]

/dev/sda:

Timing cached reads: 2532 MB in 2.00 seconds = 1265.95 MB/sec

Timing buffered disk reads: 270 MB in 3.02 seconds = 89.53 MB/sec

/dev/sdb:

Timing cached reads: 2516 MB in 2.00 seconds = 1258.07 MB/sec

Timing buffered disk reads: 264 MB in 3.02 seconds = 87.37 MB/sec

/dev/sdc:

Timing cached reads: 2442 MB in 2.00 seconds = 1220.80 MB/sec

Timing buffered disk reads: 272 MB in 3.00 seconds = 90.60 MB/sec

/dev/sdd:

Timing cached reads: 2520 MB in 2.00 seconds = 1259.64 MB/sec

Timing buffered disk reads: 272 MB in 3.02 seconds = 90.07 MB/sec

/dev/sde:

Timing cached reads: 2524 MB in 2.00 seconds = 1261.48 MB/sec

Timing buffered disk reads: 306 MB in 3.01 seconds = 101.56 MB/sec

/dev/sdf:

Timing cached reads: 2366 MB in 2.00 seconds = 1183.28 MB/sec

Timing buffered disk reads: 388 MB in 3.01 seconds = 128.88 MB/sec

/dev/sdg:

Timing cached reads: 2536 MB in 2.00 seconds = 1267.52 MB/sec

Timing buffered disk reads: 400 MB in 3.00 seconds = 133.12 MB/sec

/dev/sdh:

Timing cached reads: 2538 MB in 2.00 seconds = 1269.08 MB/sec

Timing buffered disk reads: 426 MB in 3.00 seconds = 141.90 MB/sec

/dev/sdi:

Timing cached reads: 2538 MB in 2.00 seconds = 1268.57 MB/sec

Timing buffered disk reads: 402 MB in 3.01 seconds = 133.69 MB/sec

Minumum mysql memory using

Posted on August 16, 2012June 4, 2015 by coder

[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqld]
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking
#skip-locking bu hatalı satır external diyecen
bind-address = 78.41.103.72 # 127.0.0.1
key_buffer = 16K
max_allowed_packet = 1M
thread_stack = 64K #192
thread_cache_size = 8
table_cache = 4
#sorun yok
sort_buffer_size = 64K
read_buffer_size = 256K
read_rnd_buffer_size = 256K
net_buffer_length = 2K
#sorun yok
#skip-bdb #hatali
#skip-innodb # hatali

myisam-recover = BACKUP
query_cache_limit = 1M
query_cache_size = 16M
expire_logs_days = 10
max_binlog_size = 5M

[mysqldump]
quick
quote-names
max_allowed_packet = 16M

[mysql]
no-auto-rehash

[isamchk]
key_buffer = 8M
sort_buffer_size = 8M

[myisamchk]
key_buffer = 8M
sort_buffer_size = 8M

[mysqlhotcopy]
interactive-timeout

!includedir /etc/mysql/conf.d/

[client]

port = 3306

socket = /var/run/mysqld/mysqld.sock

[mysqld_safe]

socket = /var/run/mysqld/mysqld.sock

nice = 0

[mysqld]

user = mysql

pid-file = /var/run/mysqld/mysqld.pid

socket = /var/run/mysqld/mysqld.sock

port = 3306

basedir = /usr

datadir = /var/lib/mysql

tmpdir = /tmp

lc-messages-dir = /usr/share/mysql

skip-external-locking

#skip-locking bu hatalı satır external diyecen

bind-address = 78.41.103.72 # 127.0.0.1

key_buffer = 16K

max_allowed_packet = 1M

thread_stack = 64K #192

thread_cache_size = 8

table_cache = 4

#sorun yok

sort_buffer_size = 64K

read_buffer_size = 256K

read_rnd_buffer_size = 256K

net_buffer_length = 2K

#sorun yok

#skip-bdb #hatali

#skip-innodb # hatali

myisam-recover = BACKUP

query_cache_limit = 1M

query_cache_size = 16M

expire_logs_days = 10

max_binlog_size = 5M

[mysqldump]

quick

quote-names

max_allowed_packet = 16M

[mysql]

no-auto-rehash

[isamchk]

key_buffer = 8M

sort_buffer_size = 8M

[myisamchk]

key_buffer = 8M

sort_buffer_size = 8M

[mysqlhotcopy]

interactive-timeout

!includedir /etc/mysql/conf.d/

ubuntu how to install java

Posted on August 16, 2012June 20, 2015 by coder

This tutorial will cover the installation of

32-bit and 64-bit Oracle Java 7 (currently version number 1.7.0_05)
 JDK/JRE on 32-bit and 64-bit Ubuntu operating systems.

1 2	32-bit and 64-bit Oracle Java 7 (currently version number 1.7.0_05) JDK/JRE on 32-bit and 64-bit Ubuntu operating systems.

These instructions will also work on Debian and Linux Mint.

Check to see if your Ubuntu Linux operating system architecture is 32-bit or 64-bit, open up a terminal and run the following command below.

 uname -a

uname -a

Java Version

 java -version

1	java -version

If you have OpenJDK installed on your system it may look like this

 java version "1.6.0_21"
OpenJDK Runtime Environment (IcedTea6 1.10pre) (6b21~pre1-0lucid1)
OpenJDK 64-Bit Server VM (build 19.0-b09, mixed mode)

java version "1.6.0_21"

OpenJDK Runtime Environment (IcedTea6 1.10pre) (6b21~pre1-0lucid1)

OpenJDK 64-Bit Server VM (build 19.0-b09, mixed mode)

If you have OpenJDK installed on your system, you have the wrong vendor version of Java installed for this exercise.
Completely remove the OpenJDK/JRE from the system if necessary
This will prevent system conflicts and confusion between different vendor versions of Java. For example, if you have the OpenJDK/JRE installed on your system, you can remove it by typing the following at the command line:

  sudo apt-get purge openjdk-\*

1	sudo apt-get purge openjdk-\*

This command will completely remove OpenJDK/JRE from your system
Create a directory to put your Oracle Java JDK and JRE binaries in, open up a terminal and create the directory /usr/local/java

sudo mkdir -p /usr/local/java

1	sudo mkdir -p /usr/local/java

Download the Oracle Java JDK/JRE for Linux. Make sure you select the correctcompressed binaries for your system architecture 32-bit or 64-bit (which end in tar.gz).

For example, if you are on Ubuntu Linux 32-bit operating system download 32-bit Oracle Java binaries.
For example, if you are on Ubuntu Linux 64-bit operating system download 64-bit Oracle Java binaries.

Copy the Oracle Java binaries into the /usr/local/java directory
In most cases, the Oracle Java binaries are downloaded to: /home/“your_user_name”/Downloads.

32-bit Oracle Java on 32-bit Ubuntu Linux installation instructions:

 sudo -s cp -r jdk-7u5-linux-i586.tar.gz /usr/local/java 
sudo -s cp -r jre-7u5-linux-i586.tar.gz /usr/local/java
cd /usr/local/java

sudo -s cp -r jdk-7u5-linux-i586.tar.gz /usr/local/java

sudo -s cp -r jre-7u5-linux-i586.tar.gz /usr/local/java

cd /usr/local/java

	#64-bit Oracle Java on 64-bit Ubuntu Linux installation instructions:
	cd /home/<strong>"your_user_name"</strong>/Downloads
	sudo -s cp -r jdk-7u5-linux-x64.tar.gz /usr/local/java
	sudo -s cp -r jre-7u5-linux-x64.tar.gz /usr/local/java
	cd /usr/local/java

#64-bit Oracle Java on 64-bit Ubuntu Linux installation instructions:

cd /home/<strong>"your_user_name"</strong>/Downloads

sudo -s cp -r jdk-7u5-linux-x64.tar.gz /usr/local/java

sudo -s cp -r jre-7u5-linux-x64.tar.gz /usr/local/java

cd /usr/local/java

Run the following commands on the downloaded Oracle Java tar.gz files. Make sure to do this as root in order to make them executable for all users on your system.
32-bit Oracle Java on 32-bit Ubuntu Linux installation instructions:

sudo -s chmod a+x jdk-7u5-linux-i586.tar.gz
sudo -s chmod a+x jre-7u5-linux-i586.tar.gz

# 64-bit Oracle Java on 64-bit Ubuntu Linux installation instructions:
sudo -s chmod a+x jdk-7u5-linux-x64.tar.gz
sudo -s chmod a+x jre-7u5-linux-x64.tar.gz

sudo -s chmod a+x jdk-7u5-linux-i586.tar.gz

sudo -s chmod a+x jre-7u5-linux-i586.tar.gz

# 64-bit Oracle Java on 64-bit Ubuntu Linux installation instructions:

sudo -s chmod a+x jdk-7u5-linux-x64.tar.gz

sudo -s chmod a+x jre-7u5-linux-x64.tar.gz

Unpack the compressed Java binaries, in the directory /usr/local/java

	sudo -s tar xvzf jdk-7u5-linux-i586.tar.gz

1	sudo -s tar xvzf jdk-7u5-linux-i586.tar.gz

	sudo -s tar xvzf jre-7u5-linux-i586.tar.gz

1	sudo -s tar xvzf jre-7u5-linux-i586.tar.gz

64-bit Oracle Java on 64-bit Ubuntu Linux installation instructions:

sudo -s tar xvzf jdk-7u5-linux-x64.tar.gz
 sudo -s tar xvzf jre-7u5-linux-x64.tar.gz

1 2	sudo -s tar xvzf jdk-7u5-linux-x64.tar.gz sudo -s tar xvzf jre-7u5-linux-x64.tar.gz

Double-check your directories. At this point, you should have two uncompressed binary directories in /usr/local/java for the Java JDK/JRE listed as:

	ls -a

ls -a

jdk1.7.0_05
jre1.7.0_05
<strong>Edit the system PATH file /etc/profile and add the following system variables to your system path</strong>. Use nano, gedit or any other text editor, as root, open up /etc/profile.

jdk1.7.0_05

jre1.7.0_05

<strong>Edit the system PATH file /etc/profile and add the following system variables to your system path</strong>. Use nano, gedit or any other text editor, as root, open up /etc/profile.

sudo gedit /etc/profile+
sudo nano /etc/profile
JAVA_HOME=/usr/local/java/jdk1.7.0_05
PATH=$PATH:$HOME/bin:$JAVA_HOME/bin
JRE_HOME=/usr/local/java/jre1.7.0_05
PATH=$PATH:$HOME/bin:$JRE_HOME/bin
export JAVA_HOME
export JRE_HOME
export PATH

sudo gedit /etc/profile+

sudo nano /etc/profile

JAVA_HOME=/usr/local/java/jdk1.7.0_05

PATH=$PATH:$HOME/bin:$JAVA_HOME/bin

JRE_HOME=/usr/local/java/jre1.7.0_05

PATH=$PATH:$HOME/bin:$JRE_HOME/bin

export JAVA_HOME

export JRE_HOME

export PATH

Inform your Ubuntu Linux system where your Oracle Java JDK/JRE is located. This will tell the system that the new Oracle Java version is available for use.this command notifies the system that Oracle Java JRE is available for use

	sudo update-alternatives --install "/usr/bin/java" "java" "/usr/local/java/jre1.7.0_05/bin/java" 1

1	sudo update-alternatives --install "/usr/bin/java" "java" "/usr/local/java/jre1.7.0_05/bin/java" 1

	sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/local/java/jdk1.7.0_05/bin/javac" 1

1	sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/local/java/jdk1.7.0_05/bin/javac" 1

this command notifies the system that Oracle Java JDK is available for use

	sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/local/java/jdk1.7.0_05/bin/javaws" 1

1	sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/local/java/jdk1.7.0_05/bin/javaws" 1

this command notifies the system that Oracle Java Web start is available for use,
Inform your Ubuntu Linux system that Oracle Java JDK/JRE must be the default Java

	sudo update-alternatives --set java /usr/local/java/jre1.7.0_05/bin/java
sudo update-alternatives --set javac /usr/local/java/jdk1.7.0_05/bin/javac
sudo update-alternatives --set javaws /usr/local/java/jdk1.7.0_05/bin/javaws
. /etc/profile

sudo update-alternatives --set java /usr/local/java/jre1.7.0_05/bin/java

sudo update-alternatives --set javac /usr/local/java/jdk1.7.0_05/bin/javac

sudo update-alternatives --set javaws /usr/local/java/jdk1.7.0_05/bin/javaws

. /etc/profile

Note your system-wide PATH /etc/profile file will reload after reboot of your Ubuntu Linux system.
Test to see if Oracle Java was installed correctly on your system. Run the following commands and note the version of Java:

java -version

1	java -version

This command displays the version of java running on your system
A successful installation of 32-bit Oracle Java will display

You should receive a message which displays:

java version "1.7.0_05"
Java(TM) SE Runtime Environment (build 1.7.0_05-b05)
 Java HotSpot(TM) Server VM (build 23.1-b03, mixed mode)
 javac -version

java version "1.7.0_05"

Java(TM) SE Runtime Environment (build 1.7.0_05-b05)

Java HotSpot(TM) Server VM (build 23.1-b03, mixed mode)

javac -version

This command lets you know that you are now able to compile Java programs from the terminal.
You should receive a message which displays:
javac 1.7.0_05
A successful installation of Oracle Java 64-bit will display
java -version
This command displays the version of java running on your system
You should receive a message which displays:

java version "1.7.0_05" Java(TM) SE Runtime Environment (build 1.7.0_05-b20) Java HotSpot(TM)
 64-Bit Server VM (build 23.0-b21, mixed mode)

 javac -version 
This command lets you know that you are now able to compile Java programs from the terminal.
 You should receive a message which displays:
 javac 1.7.0_05

java version "1.7.0_05" Java(TM) SE Runtime Environment (build 1.7.0_05-b20) Java HotSpot(TM)

64-Bit Server VM (build 23.0-b21, mixed mode)

javac -version

This command lets you know that you are now able to compile Java programs from the terminal.

You should receive a message which displays:

javac 1.7.0_05

Congratulations, you just installed Oracle Java on your Linux system.

Now reboot your Ubuntu Linux system.
Afterwards, your system will be fully configured for running and developing Java programs.

Unable to resolve host -fixed

Posted on August 15, 2012June 4, 2015 by coder

sudo: unable to resolve host PC_COMPUTER

fixed with using this command lines:

$nano /etc/hosts #and add your new host name to the 127.0.0.1 line

1	$nano /etc/hosts #and add your new host name to the 127.0.0.1 line

AFter it looks like:

127.0.0.1 localhost
192.168.2.2 PC_COMPUTER

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

Replace "PC_COMPUTER_ OLD NAME ..." in the above example by your new hostname as stated in the /etc/hostname file.

127.0.0.1 localhost

192.168.2.2 PC_COMPUTER

# The following lines are desirable for IPv6 capable hosts

::1 ip6-localhost ip6-loopback

fe00::0 ip6-localnet

ff00::0 ip6-mcastprefix

ff02::1 ip6-allnodes

ff02::2 ip6-allrouters

Replace "PC_COMPUTER_ OLD NAME ..." in the above example by your new hostname as stated in the /etc/hostname file.

Create a Good Password using Terminal

Posted on August 15, 2012June 4, 2015 by coder

If you’re not the best at making passwords or just don’t want to make one up right off the spot, you would usually run third party applications to generate a good password for you.

Why download third party apps when you already have a password generator for you just waiting to be used in the Terminal?

To create a password:

1. Access Terminal. Username>Applications>Utilities>Terminal
2. On the line provided, write openssl rand -base64 6.
3. Terminal will generate an eight character password for you.

openssl rand -base64 6

1	openssl rand -base64 6

how to get hardware information on terminal

Posted on August 15, 2012June 6, 2015 by coder

Hardware information can be quite difficult to obtain for certain components of the system. Nonetheless, having the knowledge about what hardware your computer has can be essential in avoiding system crashes by verifying minimum system requirements for games, heavy applications and the like. dmidecode is a tool that provides a description of the system’s hardware, along with other handy information such as firmware details and serial numbers. It is often the case that such information is required for obtaining or updating associated hardware and software for a computers peripheral device.

lshw

lshw

To extract details system information, open a Terminal from Applications Accessories and enter the following command:

sudo dmidecode

1	sudo dmidecode

This will display detailed system information within the terminal. Simply copy and paste the information to a word processor or text editor (optionally) to get an elaborate overview of your system.

The available information includes the following:

BIOS information, Vendor, release date, runtime size, ROM size, ISA, PNP, PCI, AMP, ESCD, CD boot, EDD, serial service, printer service, ACPI, AGP, USB (legacy), support information, serial numbers and much more.

The information obtained from dmidecode is so detailed that it might take you up to 20-25 seconds just to scroll down the terminal window, before you reach the end of the available content.

Ways To Search For Files Using The Terminal

Posted on August 11, 2012June 4, 2015 by coder

Today we will look at some of the common ways to search for files in Linux using the Terminal.

1) find : To search for files on the command line you can use the command “find”. The following is syntax for the “find” command:

find path criteria action

“path” – The section of the files system to search (the specific directories and all the sub directories). If nothing is specified the file system below the current directory is used.

“criteria” – The file properties.

“action” – Options that influence conditions or control the search as a whole, ie,
“–print”

2) locate : The command “locate” is an alternative to the command “find -name”. The command find must search through the selected part of the file system, a process that can be quite slow. On the other hand, locate searches through a database previously created for this purpose (/var/lib/locatedb), making it much faster. The database is automatically created and updated daily. But change made after the update has been performed are not taken into account by locate, unless the database is updated manually using the command updatedb.

3) whereis : The command “whereis” returns the binaries (option -b), manual pages (option -m), and the source code (option -s) of the specific command. If no options is used all the information is returned, if the information is available. This command is faster than “find” but is less thorough.

4) which : The “which” command searches all paths listed in the variable PATH for the specific command and returns the full path of the command. the command is specifically useful if several version of a command exist in different directories and you want to know which version is executed when entered without specifying a path.

5) type : The “type” command can be used to find out what kind of command is executed when command is entered – a shell built in command or an external command. The option -a delivers all instances of a command bearing this name in the file system.

2007-11-22-154354_1280x800_scrot

Page 19 of 23

« 1 … 17 18 19 20 21 … 23 »