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Asset ID: 1-71-1011368.1
Update Date:2010-01-06
Keywords:

Solution Type  Technical Instruction Sure

Solution  1011368.1 :   Sun StorageTek[TM] 5000 Series NAS: How to check LUN and RAID cache status  


Related Items
  • Sun Storage 5210 NAS Appliance
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  • Sun Storage 5220 NAS Appliance
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  • Sun Storage 5310 NAS Appliance
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  • Sun Storage 5320 NAS Gateway/Cluster System
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  • Sun Storage 5320 NAS Appliance
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Related Categories
  • GCS>Sun Microsystems>Storage - Disk>Network Attached Storage
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PreviouslyPublishedAs
215598


Description
Description

Symptoms:

  • Performance issues

Purpose/scope:

Performance can be severely degraded if LUNs are in a non-optimal state (i.e. degraded or rebuilding), or if the RAID cache is disabled for any reason (e.g. expired battery, incorrect settings).

This document explains how to check for each of these conditions.



Steps to Follow
The easiest way to check the LUN and cache settings is by using the system diagnostics screen. Follow these steps to access the system diagnostics:
  • Connect to the NAS using telnet or ssh.
  • Enter the administrator password.
  • Type menu
  • Locate the Extensions portion of the menu at the bottom right of the screen.
  • Press the space bar until Diagnostics is listed as an option.
  • Select the letter corresponding to Diagnostics

In the diagnostics screen, you can use the spacebar and the b key to scroll forward and backward. Alternatively, you can save the file and review it with a text editor. In either case locate Disk Subsystem Information, near the top of the output.

The following is abbreviated sample output with instructions for analysis interspersed. Note that all of the individual drive status has been removed for clarity:

 Disk Sub-System Information
---------------------------
 - Controllers Information
-----------------------
Number of Controllers : 2
   ~ Controller : 0
     Firmware Version : 06.19.25.10
Model Name       : 3992
Vendor Name      : SUN
Bus Width        : Fiber
Bus Speed        : Fiber 2Gbps
Bus Type         : Fiber
Partner status   : Active
Number of Enclosures	: 1
Sysmon Legacy Mode        : Disabled
Configured LUNs  : 2
Maximum Channels : 16
Maximum Targets  : 16
Maximum LUNs     : 255
Maximum Events   : 0
Number of Physical Channels : 15
Number of Critical Luns     : 0
Number of Offline Luns      : 0
Bus interface Speed         : 2000
Battery Backup              : Present
Memory size                 : 160
Memory speed                : 0
Cache size                  : 811
Clock speed                 : 0
Hardware speed              : 0
Memory Type                 : DRAM
Memory error correction     : None
Memory mode                 : ---

This is the controller status for controller 0. Key data are 'Number of Offline LUNS" and "Number of Critical LUNS". If these are non-zero, you have likely found the source of the performance problem. Also, the "Battery Backup" should be "Present", otherwise write-back cache will be disabled.

 - LUN Information
---------------
   ~ LUN : 0
     Raid Level                    : 5
Cache Policy                  : Write Back
Read Ahead Enable             : Yes
Number of devices in this LUN : 7
Size                          : 1713540 MB
Stripe Size                   : 64
LUN Name                      : isp1d010
LUN ID                        : 60:0A:0B:80:00:26:AB:C0:00:00:06:9F:46:1A:27:DA
LUN state                     : Online
 - LUN Information
---------------
   ~ LUN : 1
     Raid Level                    : 5
Cache Policy                  : Write Back
Read Ahead Enable             : Yes
Number of devices in this LUN : 7
Size                          : 1713540 MB
Stripe Size                   : 64
LUN Name                      : isp5d041
LUN ID                        : 60:0A:0B:80:00:26:AB:C0:00:00:06:99:46:19:E5:6E
LUN state                     : Online

This is the LUN information section. The key fields here are "Cache Policy" and "LUN state". Anything except "Write Back" and "Online" indicates a problem.

 - Sub System Information
----------------------
Battery power status  : Good
Current Power Value   : 0 minutes
Maximum Power Value   : 0 minutes
Threshold Power Value : 0 minutes
Battery Charge        : 95%
Battery Type          : Lithium Ion
Battery Age           : 172 days
Battery Life Remaining: 997 days
Battery Version       : 1

This is the battery subsystem information section for controller 0. The key fields here are "Battery power status" and "Battery Charge". Battery power status should be "Good", and "Battery Charge" should be near 100%. There should also be quite a bit of "Battery Life Remaining". A failed, failing or expired battery chould disable write-back cache for all connected LUNs and drastically reduce performance.

(Controller 1 data would normally follow here in the same order.)

* LunPath Information
-------------------
Dasdid 600 isp1d021 has 2 paths, Owner Real 1 Current 1 ; isp1d021 is the default path
P1: isp1d021 status(3) UP ACTIVE ; isp1d021 is the current path
P2: isp2d001 status(1) UP ; isp2d001 is the standby path
Dasdid 700 isp1d022 has 2 paths, Owner Real 2 Current 2 ; isp1d022 is the default path
P1: isp1d022 status(1) UP ; isp1d022 is the standby path
P2: isp2d002 status(3) UP ACTIVE ; isp2d002 is the current path


When default path does not match current path, "W" flag is displayed from cli menu :
cli> menu -> LUN Paths
Path (HBA/SID)
Lun Available Active Primary
A. isp1d021 /vol00 /vol01 612.8MB 1/2 1/2 OK
B. isp1d022 /vol10 /vol11 612.8MB 2/0 1/2 W <-- W flag

"Owner Real X Current Y" is the LUN assignment information for a cluster system. You have to ensure that Real (X) and Current (Y) owner match (otherwise a cluster failover or misconfiguration has occurred).
For load balancing purposes each head should own a similar amount of LUNs


Product
Sun StorageTek 5320 NAS Gateway/Cluster System
Sun StorageTek 5320 NAS Appliance
Sun StorageTek 5320
Sun StorageTek 5310 NAS Gateway/Cluster System
Sun StorageTek 5310 NAS Gateway System
Sun StorageTek 5310 NAS Appliance
Sun StorageTek 5220 NAS Appliance
Sun StorageTek 5210 NAS Appliance

Internal Comments
This document contains normalized content and is managed by the the Domain Lead(s) of the respective domains. To notify content owners of a knowledge gap contained in this document, and/or prior to updating this document, please contact the domain engineers that are managing this document via the “Document Feedback” alias(es) listed below:

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NAS, normalized, performance, cache, LUNs
Previously Published As
90742

Change History
Date: 2010-01-03
User Name: Will Harper
Action: Currency check
Comment: Changed title to assist findability
Date: 2007-10-03
User Name: 31620
Action: Approved
Comment: Verified Metadata - ok
Verified Keywords - ok (normalised)
no dependent articles identified
Verified still correct for audience - currently set to contract
Audience left at contract as per FvF at
http://kmo.central/howto/content/voyager-contributor-standards.html
Checked review date - currently set to 2008-09-22
Checked for TM - ok as presented
Publishing under the current publication rules of 18 Apr 2005:
Version: 3
Date: 2007-10-01
User Name: 31620
Action: Accept
Comment:
Version: 0

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