Features and Benefits: Dell Flexible Array Storage Tool
User's Guide
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Features and Benefits:
Dell™ Flexible Array Storage Tool
User's Guide
| Utilities for Creating and Managing Data Storage |
• Battery-backed Cache Memory |
• Single-step Container Creation |
• Single-step Container Reconfiguration |
• Monitoring and Event Notification |
• Recovering from Disk Failures |
• Disk Hot-swap and Maintenance |
• Summary of Features and Benefits |
This chapter highlights the key features of the controller management software. For detailed information on how to use these features, refer to the remainder of this user's guide or to the Command Line Interface Reference Guide at www.dell.com .
Utilities for Creating and Managing Data Storage
The controller management software provides a set of easy-to-use utilities for creating and managing data storage. The controller management software consists of the following utilities:
Flexible Array Storage Tool (FAST)
FAST provides a graphical user interface (GUI) and wizards that simplify storage management operations such as container creation and reconfiguration. Using FAST, you can manage containers locally or remotely without interrupting user access to data.
Some highlights of FAST include:
- Expand and reconfigure containers without taking the containers offline
- An intuitive GUI with online help that is easily launched from the desktop or from HP OpenView® NNM Special Edition with Dell OpenManageTM HIP
- Wizards that create or reconfigure containers and handle all necessary file system interactions in one step
- Manage controllers on Windows NT, Windows 2000, or NetWareTM systems, either locally or across a network, from a Windows NT management station
Command Line Interface (CLI)
The CLI is designed for advanced use and troubleshooting. The CLI provides a command set that enables you to manage containers locally on NetWare, Windows NT, and Windows 2000 systems, or remotely from within FAST on Windows NT clients. The CLI allows you to create scripts for automating container management operations. See the Command Line Interface Reference Guide for detailed information on the commands provided by the CLI.
Battery-backed Cache Memory
Note:
This feature is only available on controllers that have a battery.
The controller includes a battery-backed buffer cache on a daughter card to protect cached data in the event of a system or power failure. See the installation guide for your controller for supported holdover times. In addition, the daughter card is removable, enabling cached data to be restored by transferring the daughter card to another system. It is recommended that you contact your service representative to transfer the daughter card.
To prevent battery failures and to maintain maximum capacity, the system sends a reminder message every six months indicating that you should recondition the battery.
Single-step Container Creation
The controller management software allows you to make flexible use of storage and to create containers in a single step for disks on a Windows NT system.
Note:
This feature is not supported on NetWareTM or Windows 2000
systems.
Flexible Use of Storage
Conventional RAID solutions present a storage model where physical disks are used as the smallest building blocks for arrays. Our controller's storage model, in contrast, presents a more flexible model where storage resources are viewed and managed as a pool of available freespace. In this model, the building blocks for containers are partitions on disks that can be combined to create containers of varying sizes and types. With FAST, you can take advantage of any available disk space and create containers that span multiple disks or multiple buses. You can create a small container by using only a portion of a disk or a very large container by using freespace across multiple disks. (When a container uses a portion of a disk, the remainder of the disk can be used for other containers.) This logical view of storage gives you the flexibility to make the most efficient use of your system storage resources.
Container Creation Wizard
The Container Creation Wizard (Figure 1) enables you to create containers in a single step and make them immediately available to users. You select the type of container to be created,the physical disks to be used, and the size of container. On Windows NT, the controller management software enables you to initialize the file system as part of the creation operation; you are not required to run a separate utility. (On Windows 2000, you must use the Microsoft Disk Management utility to initialize a file system.)
Figure 1. Container Creation Wizard
Single-step Container Reconfiguration
FAST provides a Container Reconfiguration Wizard to step you through a variety of container reconfiguration operations. The Container Reconfiguration Wizard supports the following features:
Online Capacity Expansion (OCE)
By monitoring disk space and usage, you can determine when it is necessary to expand the amount of space reserved for any given container. Using the Container Reconfiguration Wizard, click on the container to be expanded and enter the new size. The expansion process occurs in the background while the container remains online and accessible to users.
If you expand and keep the same RAID type (for example, expand a 1-GB RAID-5 set to 2 GB), the data is redistributed across the disks. During the redistribution process, you maintain the fault tolerance and performance characteristics of the original type of container, but performance may degrade until the operation completes. Users have access to the data during the reconfiguration process.
RAID-level Migration
Over time, you might determine that the performance and redundancy characteristics of a container's initial RAID level are no longer appropriate. In addition to being able to expand capacity, the Container Reconfiguration Wizard allows you to change a container's type or RAID level. For example, you can use the Container Reconfiguration Wizard to add fault-tolerant characteristics to a stripe set (RAID 0) by converting it to a RAID-5 set in a simple online operation. Use the Container Reconfiguration Wizard to select the container that you want to change and the type of container to which you want to migrate. The Wizard provides information about the attributes of the container type to assist you in selecting the appropriate target container.
Monitoring and Event Notification
The controller management software allows you to monitor system resources, such as disks, controllers, and containers, and to receive e-mail messages about a variety of events related to operations and activities that occur on these system resources. The monitoring and event notification features that the controller management software provides include the following:
- Multiple views of storage
- Performance Monitor integration (Windows NT and Windows 2000 only)
- Drive statistics
- Enclosure environment
- E-mail and pager notification (Windows NT and Windows 2000 only)
Multiple View of Storage
Through FAST, you can display system resources in one of three ways: the Disk view, the Controller view, or the Container view. These views allow you to monitor and manage disks, controllers, containers, and SAF-TE 1.0 enclosures from a single application.
Performance Monitor Integration
On Windows NT and Windows 2000 systems, you can launch the Microsoft Performance Monitor from within FAST. You can also enable standard counters in the Performance Monitor to monitor device usage, queue lengths, delays, and other information used to measure throughput and overall performance.
Drive Statistics (S.M.A.R.T.)
The controller management software monitors the Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.) disk parameters to help predict the likelihood of a drive failure. It issues warnings when these parameters indicate a possible problem.
Enclosure Environment (SAF-TE)
FAST enables you to display and manage SCSI Accessed Fault-Tolerant Enclosures (SAF-TE). You can easily manage the basic elements of an enclosure (temperature sensors, fans, and power supplies). For example, you can see the current temperature of an enclosure and receive a warning when the temperature has exceeded a threshold you specify. You can then turn fans on and off, or set them to operate at different speeds to control the temperature.
The actual capabilities of an enclosure that FAST can control depend on the implementation of the enclosure. Dell enclosures are only partly controllable by FAST. Additional control is achieved through the use of other tools. (See your enclosure documentation for details.)
E-mail and Pager Notification
On Windows NT and Windows 2000 systems, you can configure the controller management software to send SNMP traps that can be received by third-party management applications. For example, all alert messages are fully integrated with HP OpenView.
Using the CLI, alarms can be set to monitor for a variety of warning or failure conditions, such as when the battery is low or degrading (only in controllers that have a battery) or when a controller fails. When a configured warning condition arises, notification is sent either by e-mail or to a pager. See the Command Line Interface Reference Guide for more information.
For information on how to configure the controller's SNMP Agent, see the installation guide for your controller.
Recovering from Disk Failures
The controller management software provides the following features related to recovering from disk failures:
- Flexible failover assignment
- Automatic failover
- Automatic data reconstruction
Flexible Failover Assignment
You can use FAST to assign failover disks to fault-tolerant containers. With conventional array solutions, failover disks are assigned on a one-to-one basis for each redundant array. The controller management software's ability to view and manage storage as a pool of free space allows you to assign failover disks on a one-to-many basis. Because each failover disk is not dedicated to a single fault-tolerant container, the same failover space can be shared by multiple containers. This method of flexible failover assignment can significantly reduce the number of dedicated failover disks needed to protect against disk failures.
Automatic Failover
For disks housed in a SAF-TE enclosure, you can replace a failed disk in a redundant container by inserting another disk into the same SAF-TE slot as the failed disk. (The inserted disk is initialized as failover begins; any data residing on this disk is destroyed.)
When I/O to a disk fails, the controller begins to monitor the disk. When you replace the failed disk with a new one, the controller detects the new disk and automatically initiates failover on the new disk. (The new disk does not have to be assigned as a failover disk for the failover to occur.)
Automatic Data Reconstruction
If a disk in a fault-tolerant container fails, the controller software automatically reconstructs the data in the replacement partitions (assigned failover space) transparently to applications. However, controller throughput may degrade during data reconstruction. (This assumes you have assigned failover space.)
If you forget to assign a failover disk to a fault-tolerant container, and a disk in that container fails, the integrity of the data (for a mirror set or a RAID-5 set) is maintained until another disk (in the same container) fails. For a stripe set of mirror sets (RAID 0/1), it is possible for multiple disks to fail and still have data integrity. The FAST utility takes advantage of these RAID attributes and notifies you that you have forgotten to assign a failover disk for the container. You then have a second chance to assign a failover disk to the container, thereby maintaining fault tolerance.
Disk Hot-swap and Maintenance
The controller management software allows you to perform the following disk maintenance tasks:
- Drive shuffling
- Drive hot-swap
Drive Shuffling
The controller management software allows you to move disks from one SCSI bus to another, or change a drive's SCSI ID on the same bus, without losing the container configuration and data.
Drive Hot-swap
The controller management software's hot-swap capability allows you to temporarily suspend I/O to the disks by using the Pause I/O command. The Pause I/O command allows you to add or remove disk drives.
Pause I/O is only required when you remove or add disks that are used by a container. If a disk is not hosting a container, you do not need to pause I/O.
Summary of Features and Benefits
| Feature |
Function |
Benefit |
| Battery backup |
Battery protects cached data |
Protects cached data in the event of a board or power failure. See installation guide for details. |
| Boot support |
Boot directly from the controller |
Separate adapter for boot device not needed. |
| Flexible container sizes |
Create containers of virtually any size using disk partitions |
Efficient use of storage; not limited to the physical disk size as the smallest building block for creating logical containers. |
| Flexible failover disk assignment |
Assign a failover disk in case a disk fails |
No dedicated disks required for failover. |
| Automatic failover |
Enables automatic failover to any new drive inserted into the same slot as a failing drive |
Does not require a dedicated disk nor does the failover disk have to be assigned before it takes effect. |
| Hot-swap |
Support for hot-swapping of disks |
Ability to replace disks without taking the system offline. |
| OCE (online capacity expansion) |
Ability to increase the capacity of a container as required |
Increase storage capacity without interrupting user access to data and without rebooting the host server system. |
| Online RAID-level migration |
Ability to change the characteristics of a container |
System managers have the flexibility to configure a container and then change its attributes as needs change without interrupting user access to data and without rebooting the host server system. |
| Remote management |
Manage controllers remotely from Windows NT system |
Network managers can manage storage from anywhere in the network. |
| SAF-TE |
Supports SAF-TE 1.0 enclosures |
Monitors and reports status of intelligent enclosures and issues warnings. |
| S.M.A.R.T. |
Supports S.M.A.R.T. disk drives |
Ability to predict disk failure prior to its occurrence and warn users. |
Single-step container creation and reconfiguration
(Windows NT only) |
Creates containers and manages the file system simultaneously |
Integrates container and file system creation; no need to use Microsoft Disk Administrator. |
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