Archive for the ‘Tips’ Category

A DaY With MySQL

Thursday, May 11th, 2006

:) I am not a MySQL expert so far…but here was my one day with the MySQL =>

I gotta requirement for MySQL Server version 5.x.x but my distro RH-AS-4 Update-1 (kernel-2.6.9-5) has MySQL-4.1.7. So I erased/un-installed all the MySQL RPMS [ rpm -e mysql* - -nodeps ]
and I choose the source bundle mysql-5.0.21, configured for a separate database on a different partition named /database and made install. Things were fine but some integration issue with Perl and PHP. Both are not able to connect MySQL (were I got screwed up).. I am sure, its not because of the php-mysql and perl-mysql packages Yeah… the default database comes under /var/lib/mysql now its /database/mysql/

I couldn’t see mysql module in php -m. Whats the solution “google” I gotta hell lot of out put that everybody saying I do have the same issue, some stamped this a as bug.

Well… now I am ready to go back to the packages ;
the RPM’s coming wih the distro [ rpm -ivh mysql*4.17* - -force :) ]

Here my DIVIDE & RULE Policy got worked. I umount the /database partition and mount to /var/lib

Issues: fstab is not ready to take the new partition
Solution: edit /etc/rc.local [ mount /dev/cciss/c0d0p11 /var/lib ]

Any luck…? the screw is still getting tight for me…

I gotta the following errors when I started using my middle finger to set this up….at different stages…

1. /usr/libexec/mysqld: Can’t change dir to ‘/var/lib/mysql/’
2. mysql error Errcode: 13
Error code 13: Permission denied [ you can try bash-3.00$ perror 13 ]
3. ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock
4. mysqld dead but subsys locked
5. /usr/libexec/mysqld: Can’t change dir to ‘/var/lib/mysql/’ (Errcode: 13)
6. Timeout error occurred trying to start MySQL Daemon.
7. ‘Problems running mysql_install_db’
8. Installation of system tables failed!

Woops..!! Dido is Stoned after The Sand In My Shoes
I un-mount the /var/lib for my old /var/lib. Confused..well

/dev/cciss/c0d0p7 4.9G 155M 4.5G 4% /var [ Created at installation ]
/dev/cciss/c0d0p11 51G 144M 48G 1% /var/lib [ Newly mounted ]

:) because I have to back up all the files under “4% /var/lib “ to “1% /var/lib” with out loosing the permission settings.

cd /var/lib
find . -print -depth | cpio -pvdum ~admin/bkup_lib

Mounted back /var/lib to /dev/cciss/c0d0p11
Remove all files under /var/lib/ and once again use the find-cpio combination to place all the files back to ” 1% /var/lib/ “

Now the time to rpm -ivh mysql* [if you are “ivh” ing WITH OUT placing the files under /var/lib …’s gonna be a PITA with depedency and if those files are not with proper permission settings…..well… whats your numer from 1 to 8 ]

If all went fine so far; one request, dont use the mysql_install_db script now, but you can have a try and collect your number :)

Good…try this

[root@python ~] /usr/bin/mysqld_safe –user=mysql –skip-grant-tables &
[root@python ~] /usr/bin/mysql mysql

Yes..! it’s running; atleast for me but with one issue that I have to manually stop/kill the mysqld daemon.
There is NO service mysqld stop/restart …
I tried all the day to get it up and once it got up…hmmm… very funny…
Do ya have any hack around… :)

Linux Partioning: To avoid chaos

Sunday, April 23rd, 2006

Dear All,

I am writing this mail as an information when we do installation of Linux Operating System by considering the manual partitioning (Diskdruid or fdisk).

People get annoyed after using Linux machine for a while by saying ” hey.. I got a Kernel Panic. I am worried about my data” or ” I don’t know where my GUI has gone

One of the reason for this panic is, your ” / ” file system got squeezed ! ( say used space for / partition is 98% )

Please do comment, if you have got any suggestion.

I suggest; its a good practice to take care of this issue from the scratch; at the time of OS installation.

Here I am considering a 40GB HDD [** workstation specific NOT Server**]

By considering the fact; most of our machines are in dual boot so I don’t wanna deal with 15GB for Windows (15GB is fair enough for viruses to play and flood around :) )

well…the rest 25 GB.

This is just a DIVIDE & RULE Policy for better management and for recovery when we had troubles.


= 100MB [Make this as the first choice when you do partition, because older BIOS were not able to detect the second part of boot loader beyond 1024 cylinders of the HDD]


= 8 GB [ Happily we can deal this for a workstations, mine is 6 GB and 73% so far ]


= Rule of Thumb; 2xRAM Size, but not always true [Try to have it on the middle part of the HDD, because its fast to access the middle portion of HDD]


= 12 GB [ If you don’t have a dual boot, add much more or go for a separate user(you) defined partition to keep your data like documents, pdfs, mp3s and other stuffs ]


= 2 GB is more than enough. Yes I said 2048 MB *


= 500 MB [ This separate partition avoid the electronic jamming of / by logfiles, mails and other junks..]
If you are using any RedHat distro and trying to configure MySQL, please consider much more space for the growing database which comes under /var/lib/mysql


= Are you trying to install any applications like Oracle db &| its client ? Do you have any “optional” application which you don’t have to mess around ?. If the answer is “yes” go ahead and allocate desired space. I feel 3-4GB is okay. The best part is, you can remove the installed package under /opt as such, because all the files will come under that particular directory (directory=pkg-name) even the “bin” files. If you are not sure about this, add up this amount of space to your /usr or /home filesystem.


= Normally, this never go beyond 100MB


1. Never log into your system as root. Log into as a normal user and configure your mail, desktop, browser and all other part which makes you comfortable. This way all your mails and other heavy stuff only fall under /home/[normalusr].

2. Do sudo or su - option when needed.

3. If you are in dual boot and have more space; its a good option to create FAT-32 partition by naming /winshare or something. So that we could access the data [pdfs, mp3s and other stuffs] from both OS.

Please do revert for any suggestion which you feel much practical or logical.

Thank You


Contrary to popular belief, Unix is user friendly.
It just happens to be selective about who it makes friends with.
Dave Parnas