My Geek Finds

If you are looking for a way to backup your home computer check out Mozy.com. They offer a 2 Gig backup for free but for just $4.95 you get unlimited backup for a single computer. They have clients for Windows and Mac.

“Mozy is a simple and safe way to back up all the important stuff on your computer. A copy of your data is stored in a secure, remote location for safekeeping, so that in the event of disaster your data is still retrievable.”

Sign up for an account, install the client, select the files you want to backup, and that’s it. There are some tweaks to allow more bandwidth to be used for backups, or backup only when idle but I just selected all the defaults. The initial backup took about 10 days for 45GBs of data, but now my data is quickly backed up daily. I am sure they are using some sort of source de-duplication similar to AVAMAR.

Here is a capture from my Mozy account of my backup data

I have not tried to do a restore yet, but I have browsed through my backed up files on the Virtual Drive created when you install the Mozy Client and using the Web restore online.

Mozy’s web restore interface

If anyone from Mozy reads this… I wish you had a Linux Client!!!

Formulas to help determine the correct size of your f_cache and p_cache for AVAMAR backups.

f_cache = N * 40MB

N = Millions of Files
So for 3 million files:
f_cache = 3 * 40MB
f_cache = 120MB

p_cache = DB Size in GB/Average Chunk * 20MB

Average Chunk Sizes:
Exchange DB: 16
Microsoft SQL DB: 24

For a 100GB Microsoft SQL DB:
p_cache = 20/24 * 20MB
p_cache = 83.3MB

Just some notes on backing up an Active Directory domain controller or the system state of any Windows client using EMC’s AVAMAR.
—

Install the AVAMAR client on the DC(s) to be backed up.

In the AVAMAR Administrator create a Dataset for the DCs (WindowsDC).

Use the Windows file system plugin and do not set any exclusions.

On the Options Tab check the Backup Windows System State check box and define a Backup label.

The AVAMAR client uses the NTBackup Utility to create a backup of the system state, it stores this backup in var in the avamar client install directory (C:\Program Files\avs\var\).  If the space on that drive is limited you can set an attribute systemstatefile with a value of the full path to store the back up – D:\avs\SystemState.bkf (after you set the attribute/value make sure to hit + to add it)

Now create a Policy Group for the Dataset and set the schedule, retention, and add the clients (the AD Domain Controllers). Once you enable the group it will be run on the schedule or it can be run on demand.

When the backup runs the AVAMAR client first uses the Windows NTBackup Utility to backup the  critical system state information such as the registry and the Sysvol directory.

Reference the AVAMAR System Administration Manual for more details on System State backup and restore.

When backuping shares on my Celerra using AVAMAR without a ndmp backup accelerator node I have to create a backup policy that connects to an avamar client on one of my servers and then runs a pre backup script to map a network drive to the remote share.

The script is just a .bat file that uses the NET USE command to map a network drive to the share on the Celerra.  This worked fine, except I noticed that only files with read access for everyone were being backed up.  All of my user profile or home directories were returning access denied errors.  I did not want to grant everyone access to all files and directories.

To fix this I had to add a username and password to the NET USE command to map the drive as a user that has read access on all directories on the shares.

I created a backup admin user for this and set all files and directories to allow this user read access.

The pre backup script mount_x.bat now looks like this:

net use /delete X:
net use X: \\NAS\Share /USER:Domain\backupadmin password

Once the backup is complete I then run a post backup script to to remove the mapping with another script umount_x.bat:

net use /delete X:

The scripts have to be in C:\Program Files\avs\etc\scripts\ on the avamar client.