Spectra Logic Spectra nTier500 User manual

Spectra nTier File Migrator
User Guide
PN 90990032 Revision A

Notices
2
Notices
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on how to return the Spectra nTier700 for a refund.
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property of their respective owners.
Spectra nTier File Migrator User Guide
Revision A, July 2008
Copyright © 2008 Spectra Logic Corporation. All rights reserved.

Contacting Spectra Logic
3
Contacting Spectra Logic
To obtain general information
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Contacting Spectra Logic
4
Notes

5
Contents
About This Guide 9
Intended Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Related Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Conventions Used in This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 1 – Overview 11
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Software Feature Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Installations Using a Tape Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Installations using Stand-alone Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Windows Offline Attribute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Determining Disk Space Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Chapter 2 – Concepts 23
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
File Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Constructing the File Name, Path Pattern, or Exclude Pattern . . . . . . . . . . . . . . 24
Examples of Allocating Files to File Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Tapes: Volumes, Volume Sets, and Automatic Replication . . . . . . . . . . . . . . . . . . . 28
Understanding Volume Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
About the Blank Media Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
About the Quarantined Media Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Partial File Restore and Cartridge Spanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Off-line File Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
File Version Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
File Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Contents
6
Chapter 3 – Installing nTier File Migrator 35
Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Access the nTier Windows Desktop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Prepare the nTier Windows Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Configure the Archive Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Disable Microsoft Removable Storage Service . . . . . . . . . . . . . . . . . . . . . . . . . 38
Remove Microsoft Services for NFS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Enable Internet Information Services (ISS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Change the Default System Name (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Install nTier File Migrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Install and Activate the Tape Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Install Device Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Enable Stand-Alone Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Activate the nTier File Migrator License . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Activate the Archive Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Start the License Administration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Complete the Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Chapter 4 – Configuring nTier File Migrator 47
Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Start the Archive Management Console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Configure Volume Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Create a New Volume Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Configure the Volume Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Configure Replication for the Volume Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Allocate Tape Cartridges to the Volume Set . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Allocate Files to File Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Create One or More New File Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Configure the File Group Listing Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Allocate Files to a File Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Set the Policies for the File Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Contents
7
Chapter 5 – Using nTier File Migrator 65
Accessing Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Access the Current Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Access Old or Deleted Versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Working with Tape Cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Importing Tapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Reformatting Tapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Setting the Administrator-Defined Information for a Tape . . . . . . . . . . . . . . . . 72
Displaying Information About a Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Verifying the Data on a Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Finalizing a Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Write-Protecting Tapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Exporting a Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Managing Volume Sets and File Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Deleting a Volume Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Renaming a File Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Retensioning Tapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Chapter 6 – System Recovery 79
System Rebuild from Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
About File System Rebuild From Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Rebuilding a File System from Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Disabling and Re-Enabling a Tape Drive or Library . . . . . . . . . . . . . . . . . . . . . . . . 80
Disabling a Tape Drive or Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Re-enabling a Tape Drive or Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Options In Case of Tape Library or Stand-Alone Drive Failure . . . . . . . . . . . . . 82

Contents
8
Chapter 7 – Diagnostics & Maintenance 83
Event Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Opening the Event Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Viewing More Detail about an Error or Warning . . . . . . . . . . . . . . . . . . . . . . . 84
Diagnostic Trace Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Opening the Trace Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Changing the Level of Detail in the Trace Log . . . . . . . . . . . . . . . . . . . . . . . . . 85
Automatic Generation of Trace Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Tape Drive and Library Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Tape Drive Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Tape Cartridge Error States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Index 89

9
About This Guide
This guide describes how to configure and use the Spectra®nTier™ File Migrator
software.
Intended Audience
This guide is intended for data center administrators and operators who maintain and
operate backup systems. It also assumes a knowledge of technical tasks such as
configuring operating systems and installing drivers.
Related Publications
The following documents are related to the Spectra nTier Intelligent Storage appliances
used with the nTier File Migrator software. For these documents and additional
information about the Spectra nTier Intelligent Storage appliances and libraries, check
the Spectra Logic web site at www.spectralogic.com/documentation.
Spectra nTier Intelligent Secondary Storage Appliances
The Spectra nTier500 Intelligent Secondary Storage Appliance User Guide provides
detailed information about installing, configuring, and using the Spectra nTier500.
The Spectra nTier700 Intelligent Secondary Storage Appliance User Guide provides
detailed information about installing, configuring, and using the Spectra nTier700.
Microsoft Windows Operating System and Software
The integrated Windows server in the Spectra nTier Intelligent Storage appliances runs
the Windows Storage Server 2003 R2 operating system. You can find information about
this operating system on the Microsoft web site at www.microsoft.com/
windowsserver2003.

About This Guide
10
Conventions Used in This Guide
This manual uses the following conventions to highlight important information:
Note: Provides additional information or suggestions about the current
topic.
Caution: Provides information you must know to avoid damage to the
library or tape drives or avoid losing data.
Warning: Provides information you must know to avoid personal injury.

1Overview
Introduction
The Spectra®nTier™File Migrator software manages data tapes and magnetic disk on
a Windows file server (a Spectra nTier Intelligent Secondary Storage appliance) to
create a highly scalable digital archive solution. The solution can be configured with a
wide range of tape libraries, stand-alone tape drives and magnetic storage. It is ideal
for archiving professional digital video, medical images, scientific and engineering
data and any application which requires a high performance data repository ranging
from a few terabytes to multiple petabytes.
The nTier File Migrator software provides the following key functionality:
Standard Windows File System Interface—The magnetic disk storage and
managed tapes appear as a single standard Windows logical drive which means
one or more software applications can write to and read from the archive as
though it were a standard disk-based logical drive letter.
Strong Data Protection—The system combines continuous data protection and
tape cartridge replication.
Hierarchical Storage Management—The solution supports online, nearline and
offline files. A file is online when it is available from magnetic disk. Nearline refers
to a file that is not on magnetic disk but is available from one or more tape
cartridges held in the library or within stand-alone tape drives. Offline refers to a
file that is not on magnetic disk but is written to one or more tape cartridges all of
which have been exported from the library and/or tape drives.
Supports WORM Tape—The solution supports both standard rewritable tape and
unalterable WORM tape. WORM tape is particularly useful for compliance
applications.

Chapter 1 – Overview
12
The nTier File Migrator software is hosted on an Windows server (for example, the
Spectra nTier700) running Microsoft Storage Server 2003 R2. The Windows server is
connected to a tape library or stand-alone tape drives and is always configured with a
dedicated logical drive that is managed by the nTier File Migrator software. Figure 1-1
shows a typical system configuration with a Spectra nTier700 and a single Spectra T50e
tape library.
When writing to and reading from tape, the system always uses the dedicated logical
drive for caching purposes. On writing to tape, a file is first written to magnetic disk
and after it has been successfully written to disk, the file goes into a queue for writing
to tape. On reading a file from tape, it is streamed onto disk cache and simultaneously
transferred over the network to fulfill the read request.
The system administrator defines policies that determine where data files are
physically stored. A single server may have many different policies, tailored to the
needs of the different file types that are being archived.
The file management policies are defined via the nTier File Migrator Archive
Management Console, which is a Microsoft Management Console (MMC) snap-in. Using
this snap-in provides a familiar administration interface which can be easily integrated
with other MMC snap-ins. The policies determine whether a file is written to tape and,
if so, allocates a specific group of tapes for the file. The policies also define whether
the tapes will be replicated and the schedule for replica updates.
Figure 1-1 An nTier700 running File Migrator and connected to a single T50 tape library.
nTier700 RAID running nTier File Migrator Spectra T50e library
LAN
Clients
Fibre Channel or SCSI connection

Introduction
13
The online retention period is set by policy and can range from permanent retention
on magnetic disk to flushing from disk as soon as the last tape replica has been
successfully written. A typical policy is illustrated in Figure 1-2.
For example, in the file management policy illustrated in Figure 1-2, a file is written to
both magnetic disk and a specified group of tape cartridges. This policy immediately
provides two copies of the file for high data integrity. The system administrator defines
the replication schedule and the number of tape copies for replication. After all copies
of the file have been produced, the file can be flushed (deleted) from magnetic disk
according to the administrator-defined policy. When a file is read, it is always retrieved
from the fastest available physical storage device. If the file is stored on both magnetic
disk and tape, the file will be read from disk. If the file is available only on tape, it will
be retrieved from tape.
The software supports both rewritable and Write-Once-Read-Many (WORM) tape
cartridges. WORM tape provides an unalterable record of the data written to it and
provides best practice when authenticity of the digital content is important. The nTier
File Migrator software supports the simultaneous use of WORM and rewritable media.
Figure 1-2 A file storage policy example.

Chapter 1 – Overview
14
The software presents the magnetic disk storage and tape library as a standard
rewritable logical drive, even when unalterable WORM tape is being used within the
library. The ability to delete and overwrite files is required by many standard
applications. Consequently, the rewritable nature of the archive allows standard
applications to work with the nTier File Migrator storage solution without need to
write any special interface software. When a file is deleted, it is no longer available
using the standard file system interface. Similarly, when a new version of a file is
written, only the latest version is available using the standard interface. The nTier File
Migrator software also includes a browser-based utility, History Explorer, which makes
it easy to identify, access and restore all old file versions and deleted files from tape.
Software Feature Overview
Standard File System—A magnetic disk logical drive and all managed tapes are
virtualized, making these physical storage devices appear as a file system within a
single logical drive letter. The solution uses the standard Windows offline file
attribute to identify when a file is no longer online.
Benefit: Seamlessly integrates with standard applications and existing network
infrastructure without modification.
Combining HSM and Data Protection—Archive Series software provides policy-
based Hierarchical Storage Management based on file deletion rather than classic
file migration.
Benefit: This approach lets the administrator match the life-cycle of a file to the
physical storage media and provides built-in data protection, removing the need for
conventional backup.
Offline Tape Cartridge Management—The system retains meta-data for offline
tape cartridges.
Benefit: The system supports an unlimited number of tapes on the shelf.
Partial Read of Large Files—Often, only a portion of a very large file needs to be
read. For example, this frequently occurs with multi-gigabyte video files when a
short clip is requested. The nTier File Migrator software supports partial reading of
large files.
Benefit: Enhanced performance when dealing with large files
Automated Tape Cartridge Replication—Tape cartridges are replicated
automatically based on the policies defined by the Administrator. When a tape
cartridge replica is reintroduced into the library after being retained off-site, it is
automatically brought up-to-date by the system.
Benefit: It is easy to rotate tape cartridges off-site for data protection purposes.

Software Feature Overview
15
Multiple Tape Set Support—The software allows file groups to be allocated to
specified groups of tapes.
Benefit: The Administrator can group related files together on the same set of
tapes.
Cartridge Spanning—The system supports storage of large files across multiple
tape cartridges.
Benefit: Results in higher use of tape capacity and also supports storage of very
large files with a size greater than that of an individual tape cartridge.
Supports both WORM and Rewritable Tape—The software simultaneously
manages both WORM and rewritable tape cartridges in the same tape library.
Policies that are set by the Administrator define which files are written to which
type of tape cartridge.
Benefit: Allows the Administrator to match tape cartridge type to the data storage
needs of the organization.
Comprehensive File Version Management—The nTier File Migrator software
provides a full audit trail of all file changes and deletions. History Explorer is a
browser-based utility that lets authorized users access all versions of a file and all
deleted files.
Benefit: Provides legal compliance and best business practice, including meeting
SEC17a-4 requirements.
Open Standard Tape Format—Open standard TAR file format is used on the tape,
allowing the tape cartridges to be read using third party utilities.
Benefit: The use of open standards on industry standard hardware ensures the
long-term availability of data.
Dynamic Expansion of Tape Sets—The system dynamically expands tape sets to
meet capacity demands.
Benefit: This minimizes system administration.
Familiar Administration—File policy and tape cartridge management is performed
by the administrator using the Archive Management Console which is a Microsoft
Management Console Snap-In.
Benefit: The Administrator uses a familiar tool for system management.
Microsoft Security—File Migrator software is fully integrated with the Microsoft
Windows security model, based on Active Directory.
Benefit: Effortlessly integrates with existing security, minimizing system
administration.
Supports High Performance Tape Formats—The software supports a number of
leading tape cartridge formats including LTO.

Chapter 1 – Overview
16
Benefit: These popular industry formats provide high capacities, high data transfer
rates and estimated data lifetimes up to 30 years without need to rewrite data or
rewind tapes.
Highly Scalable—The nTier File Migrator software supports unlimited RAID
capacity and tape libraries with capacities from less than 1 TB to over 1PB.
Benefit: Works easily with tape libraries, independent of their capacities.
API Available—An API is available.
Benefit: This can be used by developers to obtain tight integration with their
applications.
Installations Using a Tape Library
The nTier File Migrator software can be configured and licensed to manage a tape
library, optionally combined with one or more data tape drives.
Figure 1-3 shows a Windows server (the nTier700) connected to tape library and a
stand-alone data tape drive. A configuration combining a tape library and a stand-alone
drive is useful when files are retained both nearline and offline. The stand-alone tape
drive is convenient for quickly bringing individual offline tapes back to nearline.
With the configuration shown in Figure 1-3, all archived files appear within one logical
drive on the Windows server (the nTier700), independent of file location—whether
those files are on a tape within the library, on a tape in the tape drive or are offline.
This single logical drive may be shared over the network, making the archive
accessible to network clients.
Figure 1-3 An nTier700 running File Migrator, connected to a T50 tape library and a stand-
alone tape drive.
nTier700 RAID running nTier File Migrator Spectra T50 library
Fibre Channel or SCSI connections
LAN
Clients
Tape drive

Installations Using a Tape Library
17
When configuring a system using a tape library, consider the following guidelines to
ensure that the library includes the appropriate number of tape drives.
With only one tape drive within the library, it is important to be careful in setting
the file management policies to prevent the single drive from becoming a
bottleneck and in turn degrading performance.
When only one drive is present, we recommend that frequently accessed files are
retained online by employing a large RAID for the dedicated logical magnetic drive
and appropriate RAID retention rules. Make sure that only one set of tapes (Volume
Set) is configured and that tape replication is scheduled to occur at a time when
there is no other writing or reading activity.
With two tape drives within the library, the concern over tape drive bottleneck is
much less severe than for a single drive system. However, we recommend that only
one Volume Set should be configured.
Three or more tape drives within one library are recommended for large or
frequently accessed archives. The nTier File Migrator software intelligently manages
many drives, allowing simultaneous writing and multiple file accesses.
All installations that include a tape library, even if it has only one drive within it,
support tape cartridge replication.

Chapter 1 – Overview
18
Installations using Stand-alone Drives
The nTier File Migrator software can be configured and licensed to manage one or
more stand-alone tape drives connected to the Windows server. Figure 1-4 shows a
Windows server (the nTier500) connected to two tape drives. Even though there are
two tape drives in this system, all archived files appear on one logical drive on the
Windows server, independent of whether those files are on a cartridge loaded in one of
the tape drives or on a cartridge stored offline. This single logical drive can be shared
over the network, making the archive accessible to network clients.
When a file is written to tape, it is first written to magnetic disk, then the file is
immediately written to tape. The system does not permit a file to be written to disk
unless there is a suitable tape with sufficient available capacity loaded into one of the
tape drives. The following sequence of events occurs when writing a file to tape:
1. The file is first written to disk cache and appears in the file system.
2. The file is immediately written to tape.
3. After the file is on tape, it is then eligible to be flushed (i.e., deleted) from the disk
cache. The disk retention period is determined by administrator settings.
The following sequence of events occurs when reading a file from a tape cartridge
loaded in one of the tape drives:
Figure 1-4 The nTier500 running File Migrator connected to two stand-alone tape drives.
Fibre Channel or SCSI connection
LAN
Clients
Offline tapes
Tape drives
nTier500 RAID running nTier File Migrator

Windows Offline Attribute
19
1. The tape is moved to the beginning of the file (or a specified portion of the file).
Note: When reading a file that is only available on an offline tape, the
system generates a Windows event log entry that identifies the
tape cartridge on which the file is store. The cartridge must be
loaded into a tape drive before the read request can be fulfilled.
2. The file (or portion of file) is streamed to the disk cache making it available for read
request.
3. When the file is closed, it is eligible to be flushed from the disk cache. The disk
retention period is determined by administrator settings.
A system with two drives can be configured to generate two copies of each tape using
the automatic replication capabilities of the nTier File Migrator software. This can be
useful if one set of tape cartridge replicas is to be held off-site for data protection
purposes. This option is not available in a system with only one stand-alone tape drive.
Windows Offline Attribute
The nTier File Migrator software uses the standard Windows offline file attribute to
identify files that are no longer online on magnetic disk storage. After a file has been
successfully written to tape and is no longer on magnetic disk, the offline attribute is
set. This Microsoft file attribute changes network timeout periods to longer access
times. This allows retrieval of files from tape. This attribute also changes the
appearance of a file within Windows Explorer—a small clock is added to the bottom
left of the file icon, as shown in Figure 1-5.
Figure 1-5 Offline file identification, as indicated by clock icon.

Chapter 1 – Overview
20
The state of the offline file attribute for the three tiers of HSM is presented in the
following table.
Determining Disk Space Requirements
The Windows server (for example, the nTier700) must be configured with at least two
logical drives on magnetic disk—a boot drive (usually C:) and another logical drive
dedicated for use by the nTier File Migrator archive. The nTier File Migrator software is
installed on the boot drive but it requires minimal available capacity. The dedicated
logical drive stores file system metadata archive. This archive is used for read and write
caching of files held on tape and for storing all files that are retained online. This
dedicated logical drive must be formatted with NTFS and must be configured as a
dynamic disk.
Capacity requirements for the dedicated logical drive vary considerably depending on
how the system is configured. The total capacity requirement is the sum of the
following.
File system metadata—Each file in the archive file system requires two NTFS
clusters. If the dedicated logical drive is formatted using the default cluster size of
4096 bytes, a file system with one million files will require 8 GB for the metadata.
Read and write caching—The dedicated logical drive provides caching for each
file that is being written and all files that are open due to being read by a program.
Using a capacity allowance of twenty times the largest file size is adequate for most
environments.
Online Files—Any group of files may be retained online. The administrator uses
the Archive Management Console to define policies for online retention. If tape
cartridge replication is not employed, the system can be configured to delete files
immediately after writing and reading, in which case the additional capacity
requirements for online files is zero. At the other extreme, the system can be
configured to keep all current files online, in which case the additional capacity
requirements for online files is the sum of all the file sizes within the file system.
HSM Tier Description Offline Attribute
Online One instance of the file is on magnetic disk and, in addition,
there may be one or more instances on tape.
Not set
Nearline At least one instance of the file is on tape within a tape library or
tape drive and no instance is on magnetic disk.
Set
Offline The file is not stored on magnetic disk and the instances on tape,
all of which have been exported from the tape libraries or ejected
from stand-alone drives.
Set