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Q. How can I backup Fedora / CentOS / Redhat Linux Directory server database?
A. You can back up your databases from the command-line using the db2bak command-line script. This script works when the server is running or when the server is stopped. Run script as follows:
The db2back script will create a backup folder with a format of year_month_day__hour (YYYY_MM_DD_hh_mm_ss). The backup folder will contain the exported LDIF files and other Berkeley databases (.db4 files).
First stop server:
Next restore the backup database. For example:
Again start the Red Hat Directory Server:
=> Populating Directory Databases – Red Hat Directory Server
Q. How do I access NAS server using NFS? I am using Redhat Linux (RHEL).
NFS (Network File System) is a protocol originally developed by Sun Microsystems.
NFS used by UNIX and Linux oses as a distributed file system which allows a computer/server/workstation to access files over a network.
NFS is a popular file-sharing protocol for Linux and UNIX. NAS (Network attached storage) also supports NFS configuration.
Linux NFS service
In order to use NFS you need to run portmap service and rpc.statd and rpc.lockd daemons. Use following commands to start these services (RedHat/Fedora Linux):
# chkconfig portmap onAssuming that NAS is configured properly you need to type following command to access NAS (please refer our sample configuration diagram):
# chkconfig nfslock on
# /etc/init.d/portmap start
# /etc/init.d/nfslock start
# mkdir /backupLinux supports UDP by default and TCP as an option. TCP may improve performance in some cases (as a side effect it may increase the CPU load on the local server). If you want to use UDP just type following command:
# mount -o tcp 18.104.22.168:/mountpoint /backup
# mount 22.214.171.124:/mount/point /backupYou can also mount NFS share by editing /etc/fstab file:
# vi /etc/fstabAppend following line:
126.96.36.199:/mountpoint /backup nfs defaults 0 0Save the file and exit to shell prompt.Try to pass following values to mount command improve NFS performance:
# mount -t nfs -o nocto, rsize=32768,wsize=32768 188.8.131.52:/mountpoint /backupWhere,
- rsize=32768,wsize=32768:This will make your nfs connection faster than with the default buffer size of 4096. risze is read size and wsize is write size.
- nocto : Suppress the retrieval of new attributes when creating a file.
There are few more options supported to tweak NFS please consult man page of nfs.
A note for FreeBSD users
NFS configuration is a relatively straightforward, all you need to do is open /etc/rc.conf and put following line (FreeBSD client system):
# vi /etc/rc.confAppend following line:
nfs_client_enable="YES"Save the file and use mount command as follows:
# /etc/init.d/nfsclient startThere are few options supported to tweak NFS client under FreeBSD please consult man page of nfs/mount for more information.
# mkdir /backup
# mount 184.108.40.206:/mountpoint /backup