Frequently Asked Questions About the Intel® Storage Controller AXXSCM3S

Last Reviewed: 11-May-2017
Article ID: 000006917

Should I create a single drive pool, or multiple pools?
Although a single pool is easier to create and monitor, multiple pools give greater control, and performance issues can be isolated from other compute modules.

Can I mix SATA and SAS drives in an MFSYS25 system?
The system supports mixing SAS drives and SSDs, or SAS drives and SATA drives, but every storage pool must be based on the same drive type, firmware and rpm. See the tested hardware and operating system list (THOL) for validated configurations with SAS and SATA drives mixed within the MFSYS25. To operate SATA drives or SSDs the AXXTM3SATA converters must be installed in every drive bay which will contain a SATA disk or an SSD. The system firmware must be at a minimum of UFU 5.0 to support SATA and SSD drives.

Does drive order matter?
The Storage Controller tracks drives by their physical location. Do not change drive slots on a live server.

Can two servers share a Virtual Drive simultaneously?
You may share a single virtual drive among multiple Compute Modules with the Shared LUN feature.

Do I have to have 2 Storage Controller Modules?
Only one Storage Controller is required. The second is optional on the MFSYS25, MFSYS25V2 or MFSYS35.

Can I copy a virtual drive to another virtual drive, or backup the entire image pool?
The Intel® Modular Server Storage Management Pack (formerly LUN Copier) feature enables virtual drive copying.

Can you store the RAID or storage pool configuration, and deploy the configuration widely?
The Intel® Modular Server Advanced Management Pack feature enables exporting and importing all system configuration, including storage configuration as a .zip file.

Can I create global spare drives? How do global spares work?
A global spare is a drive that can be used by any RAID array with drives of the same physical capacity, and is not dedicated to one in particular.

What is a reversible spare drive?
RAID migration will be performed to this drive if another drive fails. Once the failed drive is replaced, the data will transition back from the reversible spare to the replacement drive.

Can you add drives from the lower bay?
Each Storage Controller is connected to both the upper and lower bay.

What is the maximum virtual drive size for the storage pool?
No artificial limit is enforced. The maximum size is the sum total of all your drive space.

What is the initial state of the storage?
There is no preconfigured storage configuration since the chassis ships without any drives installed. This allows you to fully customize the storage subsystem.

How do I configure my external RAID subsystem through the GUI? Do I have to attach it to both SCMs if I run in dual-mode?
The external storage array management software must be used to configure all drives within the array. Please see the tested hardware and operating system list (THOL) for the list of peripherals that can be attached to the external SAS port. You must order external RAID subsystem units with a second controller to be able to attach to both SCMs simultaneously.

If my SCM fails, will I lose my drive information?
The drive information is stored as meta-data on the hard drives. Drive information will be saved even if you replace the SCM.

How can I optimize my RAID performance?
Multiple storage pools optimize performance.

What do I need to consider if I enable disk caching to increase performance?
Any Modular Server system which has disk caching enabled should be secured by an uninterruptible power supply (UPS). A power loss during I/O transactions with disk caching enabled, may result in data loss or data corruption.

What read/write speed should I expect?
This question is dependent on the pool size, RAID type, number of hard drives, operating system, and benchmark tool used.

What is the maximum speed of the controller or backplane?
Each storage controller has six separate dedicated 3Gbps connections, one to each compute module.

How much memory is on the module?
The Storage Controller Module has 512 MB.

What are background tasks and why do they impact performance?
Background tasks are activities which run in the background, only consuming a set amount of system resources. The scheduled tasks, such as Media Patrol, Spare Check and Redundancy Check, are implemented to check and safeguard the health of physical and virtual drives. A rebuild after a disk failure is also running as background task. As these tasks need a certain amount of system resources, a performance impact may be seen when they are running.

Can I re-schedule or disable the scheduled tasks?
Scheduled tasks run at specific times:

  • Media Patrol: The first Saturday of each month, start at 3:00 AM
  • Spare Check: Every Tuesday, start at 3:00 AM
  • Redundancy Check: The second Sunday of each month, start at 3:00 AM

Scheduling for Media Patrol and Spare Check cannot be changed or disabled. The Redundancy Check can be disabled with firmware UFU 6.6 or later.

What is SCM affinity?
On Virtual drives, the Affinity/action column indicates which SCM is the preferred controller (affinity property) and to which SCM the VD will fail over to. These are configurable in the VD configuration area. Failover will only be available if the second SCM is installed.

How do I connect external devices to the SCM?
View the back of the chassis, and select the SCM. Select Actions - Expansion Port. Choose the module that will use the external device, and click Apply.

See the Promise* VTrak Connection Guide for more information.

What is the “Prepare for Transport” Option?
The Prepare for Transport Option is useful if all hard drives are to be moved to another chassis. This option will write the entire storage configuration including server assignments and SCM affinity to all hard drives. This ensures that the SCM in the new chassis will recognize the entire storage configuration, even if the drives are not inserted into the same chassis slots they previously occupied.