As part of setting up your partitioned database system on Linux® operating systems, you need to create a Db2® home file system.
Then you must NFS export the home file system and mount it from each computer participating in the
partitioned database system.
About this task
You must have a file system that is available to all machines that will participate in your
partitioned database system. This file system will be used as the instance home directory.
For configurations that use more than one machine for a single database instance, NFS (Network
File System) is used to share this file system. Typically, one machine in a cluster is used to
export the file system using NFS, and the remaining machines in the cluster mount the NFS file
system from this machine. The machine that exports the file system has the file system mounted
locally.
For more
information on setting up NFS on Db2 products, see Setting up DB2 for UNIX and Linux on NFS mounted file systems.
For more command information, see your Linux distribution documentation.
Procedure
To create, NFS export, and NFS mount the Db2 home file system,
perform the following steps:
- On one machine, select a disk partition or create one using
fdisk.
-
Using a utility like mkfs, create a file system on this partition.
The file system should be large enough to contain the necessary Db2 program files as well
as enough space for your database needs.
- Locally mount the file system you have just created and add an entry to the
/etc/fstab file so that this file system is mounted each time the system is
rebooted.
For
example:
/dev/hda1 /db2home ext3 defaults 1 2
- To automatically export an NFS file system on Linux at boot time, add an entry to the /etc/exports file.
Be sure to include all of the host names participating in the cluster as well as all of the
names that a machine might be known as. Also, ensure that each machine in the cluster has root
authority on the exported file system by using the "root" option.
The
/etc/exports file is an ASCII file which contains the following type of
information:
/db2home machine1_name(rw) machine2_name(rw)
To
export the NFS directory, run
/usr/sbin/exportfs -r
- On each of the remaining machines in the cluster, add an entry to the
/etc/fstab file to NFS mount the file system automatically at boot
time.
As in the following example, when you specify the mount point options, ensure that
the file system is mounted at boot time, is read-write, is mounted hard, includes the
bg (background) option, and that setuid programs can be run
properly.
fusion-en:/db2home /db2home nfs rw,timeo=7,
hard,intr,bg,suid,lock
where
fusion-en represents the machine name.
- NFS mount the exported file system on each of the remaining machines in the cluster.
Enter the following command:
mount /db2home
If the
mount command fails, use the
showmount command to check the
status of the NFS server. For example:
showmount -e fusion-en
where
fusion-en
represents the machine name.
This
showmount command should list the file
systems which are exported from the machine named
fusion-en. If this command fails,
the NFS server may not have been started. Run the following command as root on the NFS server to
start the server manually:
/etc/rc.d/init.d/nfs restart
Assuming the present
run level is 3, you can have this command run automatically at boot time by renaming
K20nfs to
S20nfs under the following directory:
/etc/rc.d/rc3.d.
Results
By performing these steps, you have completed the following tasks:
- On a single computer in the partitioned database environment, you have created a file system to
be used as the instance and home directory.
- If you have a configuration that uses more than one machine for a single database instance, you
have exported this file system using NFS.
- You have mounted the exported file system on each participating computer.