Author: paul.deluca

How do I allow more than 10 telnet sessions from an IP on Linux?

By default, RHEL limits the number of telnet connections from a single host to 10 simultaneous sessions. This is a security feature, but can be a problem in thin-client environments where many legitimate users connect from the same source IP address. To raise the limit:

  • Open the /etc/xinetd.conf file for editing
vim /etc/xinetd.conf
  • Find the line containing the “per_source” value
  • Increase the integer from 10 to an appropriately-sized value for your environment
  • Save the configuration file
  • Reload xinetd
service xinetd reload

How do I mount an NTFS drive in Linux?

The following procedure can be used to mount an NTFS partition — for example, an external USB drive formatted for use in Windows — for use in Linux:
rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
  • Install the fuse-ntfs-3g package:
yum -y install fuse-ntfs-3g

  • Create a mount point:
mkdir -p /mnt/usb
  • Find the device ID and partition number (ie /dev/sdc2):
fdisk -l
  • Update /etc/fstab:
cp /etc/fstab /etc/fstab.`date +%Y%m%d.%H%M%S`
vim /etc/fstab
/dev/sdc2               /mnt/usb         ntfs-3g rw,umask=0000,defaults 0 0
  • Mount the drive:
mount /mnt/usb

Configure Alias IP Address in AIX

Smit tcpip, Further Configuration, Network Interfaces, Network Interface Selection, Configure Aliases, Add an IPV4 Network Alias, Select appropriate network interface:

en0 1L-08 Standard Ethernet Network Interface

then, enter alias IP address and network mask such as 255.255.255.0.

The interface en0 was selected above since that is the most common. You may be using en1 or en2, so select the one that is appropriate for your environment.

How do I test my backup?

The correct procedure for testing the integrity of a backup — tape or network — is a three-step process that can be completed in part or in whole, depending on what particular function of the backup you are interested in verifying:

  1. Perform a full restore of the tape or network backup to a temporary directory or separate test server. This verifies that the correct restore procedures are documented, detects media errors or problems with the network restore process, and confirms availability of the necessary data files.
  2. Run the UniVerse uvbackup tool against the restored data. This verifies that the database files are in a consistent, unbroken state.
  3. Launch Eclipse and process orders, run reports, etc. to compare the operation of the restored data with behavior in the live database. This verifies that the database’s important files are all available and in a state consistent with one another.