2006 Nov 15 - Wed

Backups With Mondo and LVM

Mondo Rescue is an excellent backup for Linux based boxes. With Debian, it is a one line install:

apt-get install mondo

As the existing partitions on the machine I needed to backup did not have enough space for the backup archive, I used LVM to create another partition out of spare drive space, created a jounalled ext3 filesystem, mounted in a directory I created for Mondo backups, and then started the archive program.

mkdir /var/backups/mondo/src
mkdir /var/backups/mondo/dst

lvcreate --size 20G --name lvBackup vg01
mke2fs -v -j /dev/vg01/lvBackup
mount /dev/mapper/vg01-lvBackup /var/backups/mondo/dst
mondoarchive

As part of the backup process, an image of /root/images/mindi/mondorescue.iso should be made to a CD. This will be used in the initial part of the restore process.

One more trick having to do with the LVM (Logical File Manager) has to do with snapshots. Since databases are typically being updated during the backup, the backup process will have obtained files in an inconsistent state. Use LVM to make a snapshot, use Mondo to backup the snapshot, and then use LVM to delete the snapshot.

lvcreate --size 500M --name lvBackupSource --snapshot /dev/vg01/lvVar
mount /dev/mapper/vg01-lvBackupSource /var/backups/mondo/src
mondoarchive
umount /var/backups/mondo/src
lvremove /dev/vg01/lvBackupSource

For the size parameter in the lvcreate command, use a size that will readily accomodate any changes made to the primary partition during the backup phase.

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Kernel Upgrades

I recently upgraded to Debian 2.6.17-2-686. A bunch of packages were held back. A few that subsequently need to be installed manually include:

• apt-get install lvm2
• apt-get install ntp

Without the upgraded userspace lvm2, the system will hang when trying to lvremove a snapshot. The system will need to be restarted to bring things back to life.

For NTP, I see they have changed the configuration file from using multiple instances of pool.ntp.org to assigning specific numbers, such as 0.debian.pool.ntp.org, in order to guarantee unique addresses from dns.

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Cisco References vol1

Cisco has a number of reference documents that are very useful in day to day network consulting, but can be a real bear to find in a pinch.

The first is Cisco Unified Callmanager 4.1 TCP and UDP Port Usage. It goes through and identifies all the TCP and UDP ports in use by the various Callmanager services. Ports are grouped into the following categories:

• Intracluster Ports Between CallManagers
• Windows and Common Ports
• Between CallManager and LDAP Directory
• Web Requests from CCMAdmin or CCMUser to CallManager
• Signalling, Media and Other Communications Between Phones and Callmanager
• PC Behind the Phone to the Phone
• Signalling, Media and Other Communications Between Gateways and Callmanager
• Communications Between Applications and CallManager

The end of the document contains a number of links regarding PIX and IOS FW Inspection and Context Based Access Control.

When trying to select a Cisco device 'based on the numbers', you'll want to take a look at Cisco's Portable Product Sheets. The key sheets have to do with performance of the various switch models and router models. In addition, there are sheets relating to Port Adaptors, NM/WIC/VWIC compatibility, VPN performance, wireless comparisons, some info on GBICS, as some stuff on phones and voice density.

Cisco's TAC Tools page has such things as a DSP Calculator, IP Subnet Calculator, and a Voice Codec Bandwidth Calculator.

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