Monitoring and rebuilding hardware RAID (Linux)
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Valid for Dedicated Servers and Bare Metal Servers.
This article walks you through monitoring a hardware RAID, detecting a defective RAID and, if necessary, rebuilding the RAID.
The Dedicated Server and Bare Metal Server products use hardware controllers from 3ware, Adaptec, Areca, Broadcom, or Dell.
Determine the hardware controller type
Use the lspci command to check which hardware controller is installed in your server. This command lists all devices on the PCI bus.
Installing lspci
If you are using a minimal system, you will need to install this program manually. To do so, enter the following command, depending on your Linux distribution:
AlmaLinux 8, AlmaLinux 9, AlmaLinux 10, Rocky Linux 8, Rocky Linux 9, and Rocky Linux 10
dnf install pciutils
Ubuntu 22.04, Ubuntu 24.04, Debian 12, and Debian 13
If you are logged in as root, you can omit `sudo`.
sudo apt-get install pciutils
To check which hardware controller is installed in your server, enter the following command:
lspci|grep RAID
Examples:
[root@localhost ~]# lspci|grep RAID
01:00.0 RAID bus controller: Adaptec Series 6 - 6G SAS/PCIe 2 (rev 01)
[root@localhost ~]# lspci|grep RAID
02:00.0 RAID bus controller: Broadcom / LSI MegaRAID Tri-Mode SAS3408 (rev 01)
[root@localhost ~]# lspci|grep RAID
01:09.0 RAID bus controller: 3ware Inc 7xxx/8xxx-series PATA/SATA-RAID (rev 01)
[root@localhost ~]# lspci|grep RAID
02:0e.0 RAID bus controller: Areca Technology Corp. ARC-1110 4-port PCI-X to SATA RAID controller
RAID controller management programs
The software required to manage the respective RAID controllers is installed by default. If necessary, you can download the software for the relevant controller from the following pages:
Adaptec RAID controllers:
https://storage.microsemi.com/en-us/downloads/
Broadcom RAID controllers:
https://www.broadcom.com/support/download-search
Dell RAID controllers:
https://www.dell.com/support/home/en-us/products
3ware RAID controllers:
https://www.broadcom.com/support/download-search
Areca RAID controllers:
View details of the hardware RAID controller
Adaptec RAID controller
The Adaptec RAID controller is managed using the command-line tool arcconf. You can use the following commands to view detailed information about the Adaptec RAID controller and its configuration:
Command: arcconf getconfig 1
Explanation: This command displays information about the RAID controller, the configuration, the RAID arrays, and the available hard drives and their current status.
Command: arcconf getconfig 1 PD
Explanation: This command displays information about the hard drives present.
Command: arcconf getlogs CONTROLLER_ID device | dead | event [clear | tabular]
Explanation: This command displays the log entries. You can specify the following parameters to define the type of log entries displayed:
DEVICE: Displays all log entries relating to faults that the controller has detected on all connected devices.
DEAD: Displays all log entries recording device and hard drive failures.
EVENT: Displays all log entries containing information about specific events (e.g. rebuilds, LDMs, etc.)
You can also specify the following parameters:
tabular: Displays the log in tabular format.
clear: Deletes the specified controller log.
Example: arcconf getlogs 1 device tabular
Command: arcconf getlogs CONTROLLER_ID device | dead | event [clear | tabular] > FILE_NAME.log
Explanation: This command writes the log entries to a file.
Example: arcconf getlogs 1 device tabular > device.log
Additional information can be found on the following page:
Broadcom and Dell RAID controllers
The Broadcom RAID controller is managed and controlled using the StorCLI command-line tool. Depending on the controller generation and operating system, use:
storcli64: For common Broadcom/LSI controllers (e.g. MegaRAID, AVAGO)
storcli2: For the latest generation of Tri-Mode controllers (NVMe/SAS/SATA).
The Dell RAID controller is managed and controlled using the PERCCLI command-line tool. Depending on the controller generation and operating system, use:
perccli64: For older generations of Dell PowerEdge RAID controllers.
perccli2: For the latest generation of Dell controllers (e.g. GraniteRapids/Blackwell systems).
Notes
- The following examples use storcli64. If you are using a Dell controller or a newer system, replace the command with perccli64, storcli2, or perccli2 as appropriate. The syntax remains virtually identical.
- If you are unsure which command-line tool is intended for your RAID controller, try the commands listed below with the ‘show’ suffix. Running the ‘wrong’ tool will simply result in an error message. It will not cause any damage.
Check the status of the RAID and the hard drives
Before replacing a hard drive, the faulty unit must be identified beyond doubt. You can use the following commands to display detailed information about the Broadcom RAID controller and its configuration:
Command: storcli64 /c0 show all
Explanation: This command displays information about the RAID controller and its configuration.
Command: storcli64 /c0/eall/sall show
Explanation: This command displays information about the existing hard drives.
Command: storcli64 /c0/eall/sall show all
Explanation: This command displays information about the available hard drives and their current status (serial number, temperature, etc.). Look out for status messages such as ‘Failed’ or ‘UBad’ (Unconfigured Bad).
Make a note of the serial numbers of both the faulty and the functioning hard drives. If a drive is no longer responding at all, list all the remaining serial numbers to identify the slot using the process of elimination.
Command: storcli64 /c0 show events
Explanation: This command retrieves the event log of the first hardware RAID controller. This command is an important tool for fault diagnosis with LSI, Broadcom or Dell PERC controllers, as it goes far beyond the standard operating system logs. It lists, in chronological order, all events that have been stored directly in the controller’s firmware.
Hardware faults: e.g. faulty hard drives, error messages during drive checks, faults relating to the battery backup unit
Status changes: e.g. start and completion of RAID reconstruction
Critical errors: e.g. fatal errors or timeouts
Command: storcli64 /c0 show events limit=50
Explanation: This command limits the output of the event log for the first hardware RAID controller to 50 entries.
Command: storcli64 /c0 show events file=raid_events.txt
Explanation: This command redirects the data from the event log of the first hardware RAID controller to the file raid_events.txt.
Additional information can be found on the following page:
Dell RAID Controller
The Dell RAID controller is managed using the PowerEdge RAID Controller Command Interface (PERCCLI). You can use the following commands to view detailed information about the Dell RAID controller and its configuration:
Command: perccli64 /c0/e32/s0 show all
Explanation: This command displays information about hard drive 0.
Command: perccli64 /c0/e32/s1 show all
Explanation: This command displays information about hard drive 1.
Command: perccli64 /c0 show
Explanation: This command displays information about the available hard drives.
Command: perccli /c0 show eventloginfo
Explanation: This command displays the log entries for controller 0.
Additional information can be found on the following page:
3ware RAID controller
To view details of the 3ware RAID controller, enter the following command:
# dmesg|grep 3ware
3ware Storage Controller device driver for Linux v1.26.02.002.
scsi0 : 3ware Storage Controller
3w-xxxx: scsi0: Found a 3ware Storage Controller at 0xd800, IRQ: 18.
scsi 0:0:0:0: Direct-Access 3ware Logical Disk 0 1.2 PQ: 0 ANSI: 0
3ware 9000 Storage Controller device driver for Linux v2.26.02.010.
tw_cli
The 3ware RAID controller is managed using the 3ware Storage Controller Management Command Line Interface. To open the Command Line Interface, enter the command tw_cli. You can use the help command to view all available commands. To exit the console, enter exit.
# tw_cli
//XXX> help
Copyright(c) 2004-2006 Applied Micro Circuits Corporation (AMCC). All rights reserved.
AMCC/3ware CLI (version 2.00.06.007)
Commands Description
-------------------------------------------------------------------
focus Changes from one object to another. For Interactive Mode Only!
show Displays information about controller(s), unit(s) and port(s).
flush Flushes write cache data to units in the system.
rescan Rescans all empty ports for new unit(s) and disk(s).
update Updates controller firmware from an image file.
commit Commit dirty DCB to storage on controller(s). (Windows only)
/cx Controller-specific commands.
/cx/ux Unit-specific commands.
/cx/px Port-specific commands.
/cx/bbu BBU-specific commands. (9000 only)
/ex Enclosure-specific commands. (9KSX/SE only)
/ex/slotx Enclosure slot-specific commands.
/ex/fanx Enclosure fan-specific commands.
/ex/tempx Enclosure temperature sensor-specific commands.
Certain commands are subject to constraints regarding controller type and model support.
Please refer to the twi_cli documentation for an explanation of the controller qualifiers.
The controller qualifiers for the Enclosure commands (/ex) also apply to Enclosure-
-element-specific commands (e.g., /ex/elementx).
Type help <command> to get more details about a particular command.
For further details, see the twi_cli documentation.
//XXX>
To view information on the status of the RAID system, enter the following command:
//XXXX> info
Ctl Model Ports Drives Units NotOpt RRate VRate BBU
------------------------------------------------------------------------
c0 8006-2LP 2 2 1 0 2 - -
//XXXX> info c0
Unit UnitType Status %RCmpl %V/I/M Stripe Size(GB) Cache AVrfy
------------------------------------------------------------------------------
u0 RAID-1 OK - - - 232.885 ON -
Port Status Unit Size Blocks Serial
---------------------------------------------------------------
p0 OK u0 232.88 GB 488397168 4ND0XYFE
p1 OK u0 232.88 GB 488397168 4ND0YH77
To view alarm messages from the hardware RAID controller, enter the following command:
//XXXX> show alarms
Ctl Date Severity Alarm Message
------------------------------------------------------------------------------
c0 - INFO (0x0F:0x0007): Initialisation complete: Unit #0
c0 - INFO (0x0F:0x000C): Initialisation started: Unit #0
An alarm message is displayed in the following format:
//XXXX> show alarms
Control Date Severity Alarm Message
------------------------------------------------------------------------------
c0 - INFO (0x0F:0x000B): Rebuild started: Unit #0
c0 - ERROR (0x0F:0x0002): Unit degraded: Unit #0
To remove a defective hard drive from the RAID via the second port, enter the following command:
user@host:~# //XXXX> maint remove c0 p1
user@host:~# Removing port /c0/p1 ... Done.
Once the defective hard drive has been replaced, the new hard drive must be recognized. To do this, enter the following command:
//XXXX> maint rescan
Rescanning controller /c0 for units and drives ...Done.
Found the following unit(s): [none].
Found the following drive(s): [/c0/p1].
To mount a hard drive on the second port and reformat it, enter the following command:
//XXXX> maint rebuild c0 u0 p1
Sending rebuild start request to /c0/u0 on 1 disk(s) [1] ... Done.
To view information about rebuilding the RAID, enter the following command:
//XXXX> info c0
Unit UnitType Status %RCmpl %V/I/M Stripe Size(GB) Cache AVrfy
------------------------------------------------------------------------------
u0 RAID-1 REBUILDING 0 - - 232.885 ON -
Port Status Unit Size Blocks Serial
---------------------------------------------------------------
p0 OK u0 232.88 GB 488397168 4ND0XYFE
p1 DEGRADED u0 232.88 GB 488397168 4ND0YH77
Monitoring 3ware RAID controllers using the 3ware Disk Manager 2 software
3ware provides the 3ware Disk Manager 2 (3dm2) software. You can use this software to manage and monitor the 3ware RAID controller.
You can download 3ware Disk Manager 2 from the following page:
https://www.broadcom.com/support/download-search
Under ‘Product Group’, select ‘Storage Adapters, Controllers, and ICs’. Then, in the ‘Product Family’ list, select ‘All Storage Adapters, Controllers, and ICs’. Under ‘Keyword’, enter your controller model (see the lspci output) and click Search.
3ware Documentation
Additional information on installation, configuration, and use can be found in the 3ware documentation. This can be found on the following page:
https://www.broadcom.com/support/download-search
Under ‘Product Group’, select the option ‘Storage Adapters, Controllers, and ICs’. Then, in the ‘Product Family’ list, select the option ‘All Storage Adapters, Controllers, and ICs’. Under ‘Keyword’, enter your controller model (see the lspci output) and click Search.
Areca RAID controller
To view details of the Areca RAID controller, enter the following command:
# dmesg|grep -i areca
ARECA RAID ADAPTER0: FIRMWARE VERSION V1.43 17 April 2007
scsi0 : Areca SATA Host Adapter RAID Controller
scsi 0:0:0:0: Direct-Access Areca ARC-1110-VOL#00 R001 PQ: 0 ANSI: 5
scsi 0:0:16:0: Processor Areca RAID controller R001 PQ: 0 ANSI: 0
Some example commands are listed below. You can access the controller via the Rescue system:
arcmsr_cli64
Copyright (c) 2004 Areca, Inc. All Rights Reserved.
Areca CLI, Version: 1.71.240 (Linux)
Controllers List
----------------------------------------
Controller#01 (PCI): ARC-1110
Current Controller: Controller#01
----------------------------------------
CMD Description
==========================================================
main Show Command Categories.
set General Settings.
rsf RaidSet Functions.
vsf VolumeSet Functions.
disk Physical Drive Functions.
sys System Functions.
net Ethernet Functions.
event Event Functions.
hw Hardware Monitor Information.
exit Exit CLI.
==========================================================
Command Format: <CMD> [Sub-Command] [Parameters].
Note: Use <CMD> -h or -help to get details.
CLI>
You can view system information using the <cmd> info command. For example, entering the command hw info displays the Hardware Monitor information:
CLI> hw info
The Hardware Monitor Information
===========================================
Fan #1 Speed (RPM): 2673
HDD #1 Temp.: 48
HDD #2 Temp.: 47
HDD #3 Temp.: 51
HDD #4 Temp. : 0
===========================================
GuiErrMsg<0x00>: Success.
CLI>
To view information about the hard drives, enter the following command:
CLI> disk info
# Model Name Serial No. Firmware Rev. Capacity State
===============================================================================
1 ST3750640AS 5QD5G7Z1 3.AAK 750.2GB RaidSet Member(1)
2 ST3750640AS 5QD5G6JR 3.AAK 750.2GB RAID set member(1)
3 ST3750640AS 5QD5G7XQ 3.AAK 750.2GB RAID set member (1)
===============================================================================
GuiErrMsg<0x00>: Success.
CLI>
You can use the following command to display system information about the Areca RAID controller:
CLI> sys info
System Information
===========================================
Main Processor: 500MHz
CPU ICache Size: 32KB
CPU DCache Size: 32KB
System Memory: 256MB/333MHz
Firmware Version: V1.43 17 April 2007
BOOT ROM Version: V1.43 17 April 2007
Serial Number: Y813CAAAAR101890
Controller Name: ARC-1110
===========================================
GuiErrMsg<0x00>: Success.
CLI>
To view current events, enter the following command:
CLI> event info
Date-Time Device Event Type
===============================================================================
9 July 2009 07:23:14 H/W MONITOR Raid Powered On
29 September 2008-29 08:06:24 H/W MONITOR Raid Powered On
2008-09-29 07:51:37 H/W MONITOR Raid Powered On
...
You can use the following command to retrieve information about the current RAID set:
CLI> rsf info
# Name Disks TotalCap FreeCap DiskChannels State
===============================================================================
1 Raid Set # 00 3 2250.5GB 0.0GB 123 Normal
===============================================================================
GuiErrMsg<0x00>: Success.
CLI>
In this example, the RAID set consists of 3 x 750 GB.
To view information about the logical RAID volumes, enter the following command:
CLI> vsf info
# Name Raid# Level Capacity Ch/Id/Lun State
===============================================================================
1 ARC-1110-VOL#00 1 Raid5 1500.3GB 00/00/00 Normal
===============================================================================
GuiErrMsg<0x00>: Success.
CLI>
If you wish to make changes to a hardware RAID using an Areca RAID controller, a password is required. The default password is "0000". Example:
<CLI> set password=0000.
Areca Documentation
For additional information on installation, configuration, and use, please refer to the Areca documentation. You can find this on the following page:
Steps to follow after replacing a hard drive
When a defective hard drive is replaced, the RAID system rebuild usually starts automatically. To ensure the RAID system continues to function correctly, we recommend that you monitor the RAID system rebuild.
Notes
- The Broadcom RAID controller is managed and controlled using the StorCLI command-line tool. Depending on the controller generation and operating system, use:
storcli64: For common Broadcom/LSI controllers (e.g. MegaRAID, AVAGO)
storcli2: For the latest generation of Tri-Mode controllers (NVMe/SAS/SATA) - The Dell RAID controller is managed and controlled using the PERCCLI command-line tool. Depending on the controller generation and operating system, use:
perccli64: For older-generation Dell RAID controllers
perccli2: For the latest generation of Dell RAID controllers (e.g. GraniteRapids/Blackwell systems) - If you are unsure which command-line tool is intended for your RAID controller, test the commands listed below with the ‘show’ option. Running the ‘wrong’ tool will simply result in an error message; it will not cause any damage.
To start the rebuild manually if necessary, enter the following command:
Broadcom
storcli64 /c[controller number]/e[enclosure ID]/s[slot ID] start rebuild
storcli2 /c[controller number]/e[enclosure ID]/s[slot ID] start rebuild
Examples:
storcli64 /c0/e16/s4 start rebuild
storcli2 /c0/e16/s4 start rebuild
Dell
perccli64 /c[controller number]/e[enclosure ID]/s[slot ID] start rebuild
perccli2 /c[controller number]/e[enclosure ID]/s[slot ID] start rebuild
Examples:
perccli64 /c0/e32/s4 start rebuild
perccli2 /c0/e32/s4 start rebuild
To monitor progress, enter the following command:
Broadcom
storcli64 /call/eall/sall show rebuild
storcli2 /call/eall/sall show rebuild
Dell
perccli64 /call/eall/sall show rebuild
perccli2 /call/eall/sall show rebuild
You can also control the rebuild using the following commands:
Broadcom
Pause:
storcli64 /c[controller number]/e[enclosure ID]/s[slot ID] pause rebuild
storcli2 /c[controller number]/e[enclosure ID]/s[slot ID] pause rebuild
Examples:
storcli64 /c0/e16/s4 pause rebuild
storcli2 /c0/e16/s4 pause rebuild
Resume:
storcli64 /c[controller number]/e[enclosure ID]/s[slot ID] resume rebuild
storcli2 /c[controller number]/e[enclosure ID]/s[slot ID] resume rebuild
Examples:
storcli64 /c0/e16/s4 resume rebuild
storcli2 /c0/e16/s4 resume rebuild
Stop rebuild:
storcli64 /c[controller number]/e[enclosure ID]/s[slot ID] stop rebuild
storcli2 /c[controller number]/e[enclosure ID]/s[slot ID] stop rebuild
Examples:
storcli64 /c0/e16/s4 stop rebuild
storcli2 /c0/e16/s4 stop rebuild
Dell
Pause rebuild:
perccli64 /c[controller number]/e[enclosure ID]/s[slot ID] pause rebuild
perccli2 /c[controller number]/e[enclosure ID]/s[slot ID] pause rebuild
Examples:
perccli64 /c0/e32/s4 pause rebuild
perccli2 /c0/e32/s4 pause rebuild
Resume rebuild:
perccli64 /c[controller number]/e[enclosure ID]/s[slot ID] resume rebuild
perccli2 /c[controller number]/e[enclosure ID]/s[slot ID] resume rebuild
Examples:
perccli64 /c0/e32/s4 resume rebuild
perccli2 /c0/e32/s4 resume rebuild
Stop rebuild:
perccli64 /c[controller number]/e[enclosure ID]/s[slot ID] stop rebuild
perccli2 /c[controller number]/e[enclosure ID]/s[slot ID] stop rebuild
Examples:
perccli64 /c0/e32/s4 stop rebuild
perccli2 /c0/e32/s4 stop rebuild
Please Note
- Unlike the ‘pause’ command, the ‘stop’ command completely aborts the rebuild. If you restart the rebuild afterwards, the controller will usually start from the beginning (0%), as the consistency of the RAID set is no longer guaranteed.
- After a ‘stop rebuild’, the hard drive's status usually reverts to ‘UGood’ (Unconfigured Good) or remains in ‘Offline/Degraded’ status, as the drive has not yet been fully synchronized.
- The ‘stop’ command is primarily used, for example, if you realize that you have accidentally started the rebuild on the wrong hard drive.
The storcli/perccli commands mentioned above apply to modern Broadcom/Dell solutions. For older existing servers using Adaptec (arcconf), 3ware (tw_cli) or Areca (arcmsr_cli), the specific manufacturer tools still apply.
- Adaptec:arcconf getconfig 1 displays the status. A rebuild usually starts automatically here as soon as a drive is marked as a ‘hot spare’ or added to a degraded array.
- 3ware: Use tw_cli /c0 show for an overview and maint rebuild to initiate a rebuild.