Linux - :D All About Open Source :) ......

Friday, June 8, 2012

Run you OWNCLOUD on CentOS/REDHAT/FEDORA

Install the following packages: yum -y install httpd php php-mysql php-mbstring php-devel mysql mysql-server zlib zlib-devel pcre-devel phpmyadmin
Download ownCloud3 sources from here
Extract and copy the resultant owncloud/ directory to /var/www/html
‘cd’ to /var/www/html and set appropriate permission to owncloud directory so that apache can read/write from/to it: $sudo chown -R apache:apache owncloud/
Start Apache server: $ sudo service httpd start
Start MySQL server: $ sudo service mysql start and change the root password using $mysqladmin -u root password PASSWORD
Create a MySQL database that you want ownCloud to use by going to: http://localhost/phpmyadmin
Start ownCloud: http://localhost/owncloud and setup other users or simply start using for storing files
Use PageKite to make your cloud publicly accessible as detailed here

Wednesday, May 30, 2012

Bandwidth limitation using "TC Command" RedHat /CentOS/Fedora/Ubuntu/SuSe

Use "tc" command.

# tc qdisc add dev eth0 root tbf limit 15Kb buffer 10Kb/8 rate 10Kbps

Check the configuration.

# tc -s qdisc
qdisc tbf 8001: dev eth0 root refcnt 2 rate 80000bit burst 10Kb lat 512.0ms
Sent 994 bytes 14 pkt (dropped 0, overlimits 0 requeues 0)
rate 0bit 0pps backlog 0b 0p requeues 0
qdisc pfifo_fast 0: dev eth1 root refcnt 2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
Sent 10861 bytes 156 pkt (dropped 0, overlimits 0 requeues 0)
rate 0bit 0pps backlog 0b 0p requeues 0
qdisc pfifo_fast 0: dev eth2 root refcnt 2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
Sent 15932 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
rate 0bit 0pps backlog 0b 0p requeues 0
qdisc pfifo_fast 0: dev eth3 root refcnt 2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
Sent 1836 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
rate 0bit 0pps backlog 0b 0p requeues 0

If you want to delete the configuration, execute the following command.

# tc qdisc del dev eth0 root

Using dump/restore command do the backup and restore whole CentOS/RedHat/Fedore/SUSE/Ubuntu.

Using dump/restore command do the backup and restore whole CentOS/RedHat/Fedore/SUSE/Ubuntu.

http://dump.sourceforge.net/isdumpdeprecated.html

# cat /etc/fstab
LABEL=/                 /                       ext3    defaults        1 1
LABEL=/boot1            /boot                   ext3    defaults        1 2
LABEL=/data             /data                   ext3    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts gid=5,mode=620 0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
LABEL=SWAP-sda5         swap                    swap    defaults        0 0

# fdisk -l
   Device Boot    Start      End    Blocks      Id System
/dev/sda1 *           1       13    104391      83 Linux
/dev/sda2            14      1925   15358140    83 Linux
/dev/sda3          1926      3200   10241437+   83 Linux
/dev/sda4          3201      4864   13366080    5   Extended
/dev/sda5          3201      3391   1534176     82 Linux swap / Solaris

# dump -0uf - /dev/sda1 | ssh root@192.168.0.14 dd of=/tmp/sda1.dump
# dump -0uf - /dev/sda2 | ssh root@192.168.0.14 dd of=/tmp/sda2.dump
# dump -0uf - /dev/sda3 | ssh root@192.168.0.14 dd of=/tmp/sda3.dump
# dump -0uf - /dev/sda4 | ssh root@192.168.0.14 dd of=/tmp/sda4.dump
# dump -0uf - /dev/sda5 | ssh root@192.168.0.14 dd of=/tmp/sda5.dump

Restore the data

# restore -rf /sda1.dump
# restore -rf /sda2.dump
# restore -rf /sda3.dump
# restore -rf /sda4.dump
# restore -rf /sda5.dump

Live CD/rescue mode first and use fdisk to create partitions and give ip address

Create a partitions on new disk

Fdisk /dev/sda

format sda1/sda2/sda3/sda5 by using the mkfs command
# mkfs.ext3 /dev/sda1
# mkfs.ext3 /dev/sda2
# mkfs.ext3 /dev/sda3
# mkfs.ext3 /dev/sda4
# mkfs.ext3 /dev/sda5

Re-label all the partitions
# e2label /dev/sda1 /boot1
# e2label /dev/sda2 /
# e2label /dev/sda3 /data
# mkswap -L SWAP-sda5 /dev/sda5

login into 192.168.0.187, and restore sda1 from a remote 192.168.0.14 sda1.dump

# ssh 192.168.0.187 "cd /mnt/sda1 && RSH=/usr/bin/ssh restore -r -f 192.168.0.14:/tmp/sda1.dump"

Please run grub-install in rescue mode first. Install grub on /dev/sda1*

Tuesday, February 14, 2012

RedHat /CentOS Tapes MT command

Working with "mt" Commands: reading and writing to tape.

    The following assumes the tape device is "/dev/st0"

    STEP 1 ( rewind the tape)

         # mt -f /dev/nst0 rewind

    STEP 2 (check to see if you are at block 0)

         # mt -f /dev/nst0 tell
           At block 0.

    STEP 3 (Backup "tar compress"  directories "today"  and "etc")

         # tar -czf /dev/nst0 today  etc

    STEP 4 (Check to see what block you are at)

          # mt -f /dev/nst0 tell

      You should get something like block 2 at this point.

    STEP 5 (Rewind the tape)

          # mt -f /dev/nst0 rewind

    STEP 6 (List the files)

          # tar -tzf /dev/nst0
             today/
             etc/
             
    STEP 7 (Restore directory "one"  into directory "junk").  Note, you
         have to first rewind the tape, since the last operation moved
         ahead 2 blocks. Check this with "mt -f /dev/nst0".

          # cd junk
          # mt -f /dev/nst0 rewind
          # mt -f /dev/nst0 tell
             At block 0.
          # tar -xzf /dev/nst0 today

    STEP 8 (Next, take a look to see what block the tape is at)

          # mt -f /dev/nst0 tell
             At block 2.

    STEP 9 (Now backup directories three  and four)

          # tar -czf /dev/nst0 kd6w2 kd6mtf

      After backing up the files, the tape should be past block 2.
      Check this.

          # mt -f /dev/nst0 tell
            At block 4.

         Currently the following exist:

               At block 1:
                    today/
                   etc/
                   kd6w2/

               At block 2:
                   kd5mtf

                 At block 4:
                   (* This is empty *)

    A few notes. You can set the blocking factor and a label
    with tar.


     $ tar --label="temp label" --create  --blocking-factor=128 --file=/dev/nst0 Notes

    But note if you try to read it with the default, incorrect blocking
    factor, then, you will get the following error:

       $ tar -t   --file=/dev/nst0
       tar: /dev/nst0: Cannot read: Cannot allocate memory
       tar: At beginning of tape, quitting now
       tar: Error is not recoverable: exiting now

    However this is easily fixed with the correct blocking factor

        $ mt -f /dev/nst0 rewind
        $ tar -t --blocking-factor=128 --file=/dev/nst0
        workingdir testarea
        conf.txt

    Take advantage of the label command.

        $ MYCOMMENTS="tape"
        $ tar --label="$(date +%F)"+"${MYCOMMENTS}"

    Writing to tape on a remote 192.168.56.5 computer

        $ tar cvzf - ./tmp | ssh -l rajat 192.168.56.5 '(mt -f /dev/nst0 rewind; dd of=/dev/st0 )'

    Restoring the contents from tape on a remote computer

        $ ssh -l rajat 192.168.56.5 '(mt -f /dev/nst0 rewind; dd if=/dev/st0  )'|tar xzf -

    Getting data off of tape with dd command with odd blocking factor. Just set ibs very high

        $ mt -f /dev/nst0 rewind
        $ tar --label="Contenets of Notes" --create  --blocking-factor=128 --file=/dev/nst0 Notes
        $ mt -f /dev/nst0 rewind
        $ dd ibs=1048576 if=/dev/st0 of=notes.tar

    The above will probably work with ibs=64k as well