Starting Dell ManagerDell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide
Using Dell Manager in Linux GUI Mode
Configuring Arrays and Logical Drives
Designating Drives as Hot Spares
Exiting the Dell Manager Utility
Dell™ Manager is a character-based, non-GUI utility that changes policies, and parameters, and monitors RAID systems. Dell Manager runs under Novell® NetWare®, and Red Hat Linux.
Make sure the program file is in the correct directory before you enter the command to start Dell Manager. For Linux, use the Dell Manager RPM to install files in the usr/sbin directory. The RPM installs them automatically in that directory. For Novell NetWare, Dell Manager has to be installed and run anywhere on a Novell server.
Type the command shown in Table 7-1 for the corresponding operating system.
Table 7-1 Command Used to Start Dell Manager
| In... | Type this: |
|---|---|
DOS |
megaconf |
Novell NetWare |
dellmgr |
Red Hat Linux |
dellmgr |
On a Linux system, for Dell Manager to work correctly in a terminal in GUI Mode, you must:
Perform the procedure below if you use console, gnome terminal, or xterm.
The linux console mode, which you select from the terminal with the File —> Linux Console command, works correctly by default. The text mode console (non-GUI) also works correctly by default.
To prepare the system to use Dell Manager, perform the following steps:
TERM=linux
Export TERM
 |
NOTE: On a Linux 8.0 system, when you run Dell Manager (v. 5.23) from a Gnome-terminal in XWindows, the <F10> key cannot be used to create a logical drive. Instead, you can use the alternate keys <Shift><0>. (This is not an issue if Xterm is used to call dellmgr). The following is a list of alternate keys you can use in case of problems with keys <F1> through <F6>, and <F10>: |
Selecting a Configuration Method •
PERC 4/SC Default Settings •
PERC 4/DC Default Settings •
Using Easy Configuration •
Using New Configuration •
Using View/Add Configuration
Perform the following operations for array and logical drive configuration:
See Selecting a Configuration Method in this section for more information.
This section describes the logical drive parameters and default settings for PERC 4/SC and PERC 4/SC and provides procedures for the configuration methods. You can select the logical drive parameters when using Easy Configuration, New Configuration, or View/Add Configuration.
Table 7-2 contains descriptions of the logical drive parameters.
Table 7-2 Logical Drive Parameters and Descriptions
| Parameter | Description |
|---|---|
RAID Level |
The number of physical drives in a specific array determines the RAID levels that can be implemented with the array. RAID 0 requires one or more physical drives. RAID 1 requires exactly two physical drives. RAID 5 requires at least three physical drives. RAID 10 requires at least four physical drives. RAID 50 requires at least six physical drives. |
Stripe Size |
Stripe Size specifies the size of the segments written to each drive in a RAID 1, 5, or 10 logical drive. You can set the stripe size to 2 KB, 4 KB, 8 KB, 16 KB, 32 KB, 64 KB, or 128 KB. The default is 64 MB for PERC 4/SC and PERC 4/DC. A larger stripe size provides better read performance, especially if your computer does mostly sequential reads. However, if you are sure that your computer does random read requests more often, select a small stripe size. |
Write Policy |
Write Policy specifies the cache write policy. You can set the write policy to Write-back or Write-through. The default is Write-through for PERC 4/SC and Write-back for PERC 4/DC. In Write-back caching, the controller sends a data transfer completion signal to the host when the controller cache has received all the data in a transaction. This setting is recommended in standard mode. In Write-through caching, the controller sends a data transfer completion signal to the host when the disk subsystem has received all the data in a transaction. This is the default setting if cluster mode is enabled. Write-through caching has a data security advantage over write-back caching. Write-back caching has a performance advantage over write-through caching. |
Read Policy |
Read-ahead enables the SCSI read-ahead feature for the logical drive. You can set this parameter to No-Read-Ahead, Read-ahead, or Adaptive. The default is Adaptive for PERC 4/SC and PERC 4/DC No-Read-Ahead specifies that the controller does not use read-ahead for the current logical drive. Read-ahead specifies that the controller uses read-ahead for the current logical drive. Adaptive specifies that the controller begins using read-ahead if the two most recent disk accesses occurred in sequential sectors. If all read requests are random, the algorithm reverts to No-Read-Ahead, however, all requests are still evaluated for possible sequential operation. This is the default setting. |
Cache Policy |
Cache Policy applies to reads on a specific logical drive. It does not affect the Read-ahead cache. The default is Direct I/O for PERC 4/SC and PERC 4/DC. Cache Policy applies to reads on a specific logical drive. It does not affect the Read-ahead cache. Cached I/O specifies that all reads are buffered in cache memory. Direct I/O specifies that reads are not buffered in cache memory. Direct I/O does not override the cache policy settings. Data is transferred to cache and the host concurrently. If the same data block is read again, it comes from cache memory. |
Span |
The choices are: Yes - Array spanning is enabled for the current logical drive. The logical drive can occupy space in more than one array. No - Array spanning is disabled for the current logical drive. The logical drive can occupy space in only one array. PERC 4 supports spanning of RAID 1 and 5 arrays. You can span two or more contiguous RAID 1 logical drives into a RAID 10 array, and two or more contiguous RAID 5 logical drives into a RAID 50 array. You need at least two hard drives in two separate RAID 1 arrays to create a RAID 10 array and at least three hard drives in two separate RAID 5 arrays to create a RAID 50 array. For two arrays to be spanned, they must have the same stripe width (they must contain the same number of physical drives) and must be consecutively numbered. For example, assuming array 2 contains four hard drives, it can be spanned only with array 1 and/or array 3, and only if arrays 1 and 3 also contain four hard drives. If the two criteria for spanning are met, PERC 4 automatically allows spanning. If the criteria are not met, the Span setting makes no difference for the current logical drive. |
Stripe size |
64 KB |
Write policy |
Write-through |
Read policy |
Adaptive |
Cache policy |
Direct I/O |
FlexRAID virtual sizing |
OFF |
FlexRAID PowerFail |
ON |
Stripe size |
64 KB |
Write policy |
Write-back |
Read policy |
Adaptive |
Cache policy |
Direct I/O |
FlexRAID virtual sizing |
OFF |
FlexRAID PowerFail |
ON (OFF for cluster enabled) |
|
NOTE: In Cluster mode, PERC 4/DC allows only write-through as the write policy. |
In Easy Configuration, each physical array you create is associated with exactly one logical drive. If logical drives have already been configured when you select Easy Configuration, the configuration information is not disturbed. You can modify the following parameters:
Perform the following steps to use Easy Configuration:
The array selection menu displays. The hot key information appears at the bottom of the screen. The hot key functions are:
<F2> Display the manufacturer data and error count for the selected drive.
<F3> Display the logical drives that have been configured.
<F4> Designate the selected drive as a hot spare.
The indicator for the selected drive changes from MASTER to ONLIN A[array number]-[drive number]. For example, ONLIN A2-3 means hard drive 3 in array 2.
Try to use drives of the same capacity in a specific array. If you use drives with different capacities in an array, all the drives in the array is treated as though they have the capacity of the smallest drive in the array.
The indicator changes to HOTSP. Making hot spares is optional. Hot spares are physical drives that are powered up along with the RAID drives and usually stay in a standby state. If a hard drive used in a RAID logical drive fails, a hot spare automatically takes its place and the data on the failed drive is reconstructed on the hot spare.
A window entitled Select Configurable Array(s) appears. It displays the array, and array number, such as A-00.
Span information, such as Span-1, displays in the array box.
|
NOTE: You can press <F2> to display the number of drives in the array, their channel and ID, and <F3> to display array information, such as the stripes, slots, and free space. |
The logical drive configuration screen appears. The window at the top of the screen shows the logical drive(s) to be configured as well as any existing logical drives.
The column headings are:
LD - The logical drive number
RAID - The RAID level
Size - The logical drive size
#Stripes - The number of stripes in the associated physical array
StrpSz - The stripe size
Drive-State The state of the logical drive
The available RAID levels for the current logical drive display.
The Array Selection screen appears if any unconfigured hard drives remain.
A list of the currently configured logical drives appears. You are prompted to save the configuration.
The Configure menu appears.
See Initializing Logical Drives in this section for more information.
If you select New Configuration, the existing configuration information on the selected controller is destroyed when the new configuration is saved. In New Configuration, you can modify the following array parameters:
Perform the following steps to use New Configuration:
An array selection window displays the devices connected to the current controller. Hot key information appears at the bottom of the screen. The hot key functions are:
<F2> Display the manufacturer data and error count for the selected drive.
<F3> Display the logical drives that have been configured.
<F4> Designate the selected drive as a hot spare.
<F10> Display the logical drive configuration screen.
The indicator for the selected drive changes from MASTER to ONLIN A[array number]-[drive number]. For example, ONLIN A2-3 means hard drive 3 in array 2.
Try to use drives of the same capacity in a specific array. If you use drives with different capacities in an array, all the drives in the array is treated as though they have the capacity of the smallest drive in the array.
The indicator changes to HOTSP. Making hot spares is optional. Hot spares are physical drives that are powered up along with the RAID drives and usually stay in a standby state. If a hard drive used in a RAID logical drive fails, a hot spare automatically takes its place and the data on the failed drive is reconstructed on the hot spare.
A window entitled Select Configurable Array(s) appears. It displays the array and array number, such as A-00.
Span information, such as Span-1, displays in the array box.
|
NOTE: You can press <F2> to display the number of drives in the array, their channel and ID, and <F3> to display array information, such as the stripes, slots, and free space. |
The logical drive configuration screen appears. The window at the top of the screen shows the logical drive(s) to be configured as well as any existing logical drives.
The column headings are:
LD - The logical drive number
RAID - The RAID level
Size - The logical drive size
#Stripes - The number of stripes in the associated physical array
StrpSz - The stripe size
DriveState - The state of the logical drive
The available RAID levels for the current logical drive are listed.
By default, the logical drive size is set to all available space in the array(s) being associated with the current logical drive, accounting for the Span setting and for partially used array space. For example, if the previous logical drive used only a part of the space in an array, the current logical drive size is set to the remaining space by default.
The RAID 1 logical drives must have the same stripe size and use the whole capacity of the hard drives.
If space remains in the arrays, the next logical drive to be configured appears.
If all array space has been used, a list of the existing logical drives appears.
See Initializing Logical Drives in this section for more information.
View/Add Configuration allows you to control the same parameters as New Configuration without disturbing the existing configuration information. Perform the following steps to use View/Add Configuration:
An array selection window displays the devices connected to the current controller. Hot key information appears at the bottom of the screen. The hot key functions are:
<F2> Display the manufacturer data and error count for the selected drive.
<F3> Display the logical drives that have been configured.
<F4> Designate the selected drive as a hot spare.
<F10> Display the logical drive configuration screen.
The indicator for the selected drive changes from MASTER to ONLIN A[array number]-[drive number]. For example, ONLIN A2-3 means hard drive 3 in array 2.
Try to use drives of the same capacity in a specific array. If you use drives with different capacities in an array, all drives in the array are treated as if they have the capacity of the smallest drive in the array.
The indicator changes to HOTSP. Making hot spares is optional. Hot spares are physical drives that are powered up along with the RAID drives and usually stay in a standby state. If a hard drive used in a RAID logical drive fails, a hot spare automatically takes its place and the data on the failed drive is reconstructed on the hot spare.
A window entitled Select Configurable Array(s) appears. It displays the array and array number, such as A-00.
Span information, such as Span-1, displays in the array box.
|
NOTE: You can press <F2> to display the number of drives in the array, their channel and ID, and <F3> to display array information, such as the stripes, slots, and free space. |
The logical drive configuration screen appears. The window at the top of the screen shows the logical drive(s) to be configured as well as any existing logical drives.
The logical drive configuration screen appears. The window at the top of the screen shows the logical drive that is currently being configured as well as any existing logical drives. The column headings are:
LD - The logical drive number
RAID - The RAID level
Size - The logical drive size
#Stripes - The number of stripes in the associated physical array
StrpSz - The stripe size
DriveState - The state of the logical drive
The available RAID levels for the current logical drive display.
By default, the logical drive size is set to all available space in the array(s) being associated with the current logical drive, accounting for the Span setting and for partially used array space. For example, if the previous logical drive used only a part of the space in an array, the current logical drive size is set to the remaining space by default.
The RAID 1 logical drives must have the same stripe size and use the whole capacity of the hard drives.
If space remains in the arrays, the next logical drive to be configured appears.
If the array space is used, a list of the existing logical drives appears.
You are prompted to save the configuration.
See Initializing Logical Drives for more information.
You should initialize each new logical drive you configure. You can initialize the logical drives in two ways:
Perform the following steps to initialize more than one logical drive at a time:
A list of the current logical drives appears.
The progress of the initialization for each drive appears in bar graph format.
Perform the following steps to initialize one logical drive at a time:
The logical drive action menu displays.
The progress of the initialization appears as a graph on the screen.
Hot spares are physical drives that are powered up along with the RAID drives and usually stay in a standby state. If a hard drive used in a RAID logical drive fails, a hot spare will automatically take its place and the data on the failed drive is reconstructed on the hot spare. Hot spares can be used for RAID levels 1, 5, 10, and 50. Each PERC 4 controller supports up to eight hot spares.
The methods for designating physical drives as hot spares are:
When you select any configuration option, a list of all physical devices connected to the current controller appears. Perform the following steps to designate a drive as a hot spare:
The indicator changes to HOTSP.
Perform the following steps to designate a hot spare:
A physical drive selection screen appears.
The indicator for the selected drive changes to HOTSP.
If a hard drive fails in an array configured as a RAID 1, 5, 10 or 50 logical drive, you can recover the lost data by rebuilding the drive. If a rebuilding spare fails, a new rebuild is started using a second spare, if available. The capacity of the second spare must be equal to or greater than the smallest hard drive that failed in the logical drive.
Table 7-3 describes the automatic and manual rebuilds.
| Type | Description |
|---|---|
Automatic Rebuild |
If you have configured hot spares, the RAID controller automatically tries to use them to rebuild failed drives. Display the Objects—> Physical Drive screen while a rebuild is in progress. The drive indicator for the hot spare hard drive has changed to REBLD A[array number]-[drive number], indicating the hard drive being replaced by the hot spare. |
Manual Rebuild |
Manual rebuild is necessary if no hot spares with enough capacity to rebuild the failed drives are available. Select Rebuild on the Dell Manager Main Menu or the Objects—> Physical Drive—> Rebuild menu. |
The list displays the actions for the physical drives.
Rebuilding can take some time, depending on the drive capacity.
A device selection window displays the devices connected to the current controller. The failed drives have FAIL indicators.
The indicators for the selected drives change to REBLD. Rebuilding can take some time, depending on the number of drives you have selected and their capacities.
Dell Manager offers the ability to delete any unwanted logical drives and use that space for a new logical drive. You can have a configuration with multiple logical drives and delete a logical drive without deleting the whole configuration.
The main benefit on the configuration module is that you are not restricted to sequential or contiguous logical drives when you create logical drives. You can use non-contiguous segments to create logical drives.
After you delete a logical drive, you can create a new one. You can use the configuration utilities to create the next logical drive from the non-contiguous free space (`holes'), and from the newly created arrays. The configuration utility provides a list of configurable arrays where there is a space to configure.
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NOTICE: The deletion of the logical drive can fail under certain conditions. Deletion can fail during a rebuild, initialization or check consistency of a logical drive, if that drive has a higher logical drive number than the drive you want to delete. |
Perform the following steps to delete logical drives:
The logical drives display.
This deletes the logical drive and makes the space it occupied available for you to create another logical drive.
Perform the following steps to remove hard drives that are hot spares:
A physical drive selection screen appears.
A prompt displays for you to fail the physical drive.
The indicator for the selected drive changes to READY.
Select Check Consistency to verify the redundant data in logical drives that use RAID levels 1 or 5. (RAID 0 does not provide data redundancy.)
When you select Check Consistency, the parameters of the existing logical drives on the current controller and a selection menu listing the logical drives by number appear. If a discrepancy is found, it is automatically corrected, assuming always that the data is correct. However, if the failure is a read error on a data drive, the bad data block is reassigned with the generated data. Perform the following steps to run the Check Consistency.
A progress indicator for each selected logical drive displays.
A message appears if uninitialized logical drives remain in the system.