How
to Create an ISA Protocol Definition
If
you are having problems with getting the client software for the
Online Backup Service working when it's running behind a Microsoft
ISA (Internet Security & Acceleration) Server, the most likely
cause is that the ISA protocol definition is not set up correctly.
You need to set the TCP/IP Outgoing port to 308.
Please
note, you do not need to configure the secondary connection.
For
more information on protocol rules: http://www.isaserver.org/
Microsoft
Structured Storage and Slack Space
When
using NovaNet-WEB, plan for approximately 5% extra disk space
when determining storage requirements - here's why.
NovaNet-WEB
and Microsoft Structured Storage - NovaNet-WEB leverages a
technology called Microsoft Structured Storage for storing all
user data. An analysis of structure storage demonstrates the ability
to create a "mini-file system" within a file (Structure Storage
Object). As such, structure storage has similar cluster constraints
to that of typical hard drive geometry. In the case of NovaNet-WEB,
the structure storage cluster size is 4kb.
Slack
Space with Hard Drives: Slack space is the amount of disk
space that is wasted by having a large cluster size in relation
to the actual file size. For example, if a 300-byte file is stored
on a disk with a cluster size of 1,024 bytes, there will be 724
bytes of slack space that can't be used for any other files.
Slack
Space with NovaNet-WEB - Since NovaNet-WEB uses a small, 4kb
cluster size, there are still many smaller files, and any single
file less than 4kb written to the storage object will occupy the
full 4kb of space. Figure 1 depicts this clearly:
Figure 1
The
same holds true if a file is only slightly larger than the cluster.
For example, a 5kb file written to the storage object will actually
occupy 8kb of space as depicted in Figure 2.
Figure 2
Based
on the above, it may appear that there could be significant wasted
space for anyone backing up many small files. However, while this
is certainly true as it applies to typical hard drive geometry,
the issue is somewhat mitigated by a technique used by MS Structure
Storage called the MiniFAT.
Unlike
traditional hard drive cluster geometry based on the FAT or MFT,
the MiniFAT permits more than one file to occupy the remaining
free space of the cluster as demonstrated in Figure 3 resulting
in the "slack space" being reclaimed.
Figure 3
Therefore,
while a single backup of a large number of small file may result
in what appears to be a significant amount of wasted space, in
practice you'll find that over time, the percentage of slack space
will decrease as more backups of individual files occur. That
being said, you will always have some small percentage of slack
space since there are many times when numerous small files, such
as shortcuts, temp files, small text files, etc, are only backed
up once. For this reason, you should plan for approximately 5%
slack space when determining storage requirements.
