SM5200 Storage Options and RAID diagnostics

NOTICE

COMPLEX PROCEDURE REQUIRED.
The resolution of this article has many complex steps that may result in unforeseen results if not performed correctly. If you are at all unfamiliar with the requirements, please contact Product Support Services for assistance.

Issue

This article describes the various storage options available for the SM5200 System Manager.

It also gives some basic information on the diagnostic tools available to check the RAID array status of the SM5200.

Product Line

Pelco Video Management

Environment

SM5200 1.0

Cause

Informational article on storage options & RAID diagnostics

Resolution

Export Storage Options

  • SM5200-03
    • single 3TB drive
  • SM5200-12
    • Four 3TB drives; RAID5
    • listed as p0-p5 internally
    • listed as 1-6 on the chassis
  • SM5200-03 has 3 empty slots; possible to add HDDs, but not supported

RAID Overview

  • LSI 3ware 9750-8i RAID controller
    • Same controller as NSM5200
  • tw_cli (ThreeWare Command Line Interface) utility used to manage the controller
    • same as on the NSM5200
  • OS Drive:
    • 40GB mirrored (RAID1)
    • SSD

Tw_cli overview

Tw_cli is a command line interface created by LSI. More in-debt information on the utility can be found on the LSI website: ftp://tsupport:tsupport@ftp0.lsil.com/private/3Ware/doc/CLIGuide_10.2codeset.pdf

This overview shows the most basic functions on the tw_cli which can help determine what is wrong with a RAID setup in the SM5200.

Running tw_cli and then running a "show" command will yield the information in Figure 1.

Figure 1

Figure 1

This will show you the number of the controller. Typing "/cx show" will then yield information on the RAID arrays and the drives controlled by the controller. See figure 2.

Figure 2

Figure 2

Example: drive 2 fails

To illustrate the usage of tw_cli, the following steps show what happens when a drive is pulled.

  • Pull drive 2 (2nd SSD out of the chassis). Figure 3 shows what happens when the drive is pulled. The RAID array will become "degraded" and as the array can no longer detect the drive, the whole port will not show in the overview (port p1 is missing).
  • Note that there is not audible alarm. There will be a red disk and warning LED and an alarm will show in the Workstation and/or VCD if the user is configured to receive alarms.

Figure 3

Figure 3

  • When running the command "/c6/u0 show" the units (RAID arrays) are shown in more detail. Figure 4 shows what this looks like.

Figure 4

Figure 4

  • Put drive 2 back and observe the controller once more

Figure 5

Figure 5

  • As can be seen, the array will start initializing first and then will start rebuilding. It goes through several steps (sometimes pausing if other actions take precedent).