help us guys, i'd setup already the RAID 1 controller which is mirroring and i'd already installed the Supported Operating System which is the RHEL version 4 AMD64/EMT64 64bit. Before we will pull the other hard drive i'l make a script to save from the database which is "mysql" and after that i ran mysql do some testing, creating and saving to make sure that our work are saved successfully from the database. Then i tried to pull one hard drive with the running OS RHEL to make sure that the hot swapping are workout. yes the operating system still running and the hot swap not quitely sure because the existing application can't launch successfully, except the app that i already opened. and the last that was very important to us is our mysql cannot launch. The error says "message from syslog@databaseserv at tue Jun 19 12:24:32 2007 databaseserv kernel: journal commit I/O error.

your help guys are very must appreciated.. Thanks in advance...

what is your current RAID level?

have you installed RAID manager monitoring tool?

after swaping the HDD, did you noticed any light blicking HDD?

if yes, then it mean its trying to resync all the drivers. give some time then reboot the box and check again.

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im on the level 1 RAID. yes i already installed raid controller manager tools and saw also a blinking HDD after i swap the other HDD. As i observed my MySQL database or application will stop that are very important to my testing. that was also my problem that my MySQL did not work after swapping the HDD. it is possible for RHEL 4 to install it again mySQL even if the RHEL 4 are already built-in MySQL? Thanks