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Asset ID: 1-71-1005958.1
Update Date:2010-08-31
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Solution Type  Technical Instruction Sure

Solution  1005958.1 :   Sun StorEdge[TM] T3, T3+, 6120: Battery Management and the Battery Scheduler Daemon  


Related Items
  • Sun Storage T3 Array
  •  
  • Sun Storage T3+ Array
  •  
  • Sun Storage 6120 Array
  •  
Related Categories
  • GCS>Sun Microsystems>Storage - Disk>Modular Disk - 6xxx Arrays
  •  
  • GCS>Sun Microsystems>Storage - Disk>Modular Disk - Other
  •  

PreviouslyPublishedAs
208286


Description
Frequently asked questions (FAQ) on T3 Battery Management and details of the T3 Battery Scheduler Daemon.



Steps to Follow
Battery Management FAQ

NOTE: All examples in this document are taken from a T3-array. The commands will be the same in a T3+ and a 6120, the outputs may vary slightly.

Q. How can I check the status of the batteries  How do I know the status of a refresh operation or when the next refresh will occur 

A. Run a 'refresh -s'.

  T3:/etc:40>refresh -s
PCU1                            PCU2
-----------------------------------------------------------------
U1                      Recharging                      Pending
U2                      Recharging                      Pending
Current Time            Fri Sep 15 17:09:01 2000
Start Time              Fri Sep 15 16:52:40 2000
Next Refresh            Fri Sep 29 16:52:40 2000
Total time elapsed :    0 hours, 16 minutes, 21 seconds.

Other options to the 'refresh' command:

   refresh -c  ----> start refresh
refresh -s  ----> get status
refresh -i  ----> re-init command file
refresh -k  ----> kill current refreshing task

Q. What determines how often the battery refreshes 

A. It is based on the BAT_CYC setting in the array's /etc/schd.conf file. It should be set to 28 (days).

You can also schedule the time for a refresh cycle to start using the following syntax:

BAT_BEG MM-DD-YYYY,hh-mm-ss

See "Battery Scheduler Daemon" section below.

( Newer versions use /etc/bat.conf ).

Q. What is the battery hold time  What does it mean if the hold time is low 

A. Battery hold time is the length of time it takes to discharge a battery during a refresh cycle ( Health Check ). The longer the time, the better the battery. The minimum battery hold time is 6 minutes. (The T3 refers to hold time in seconds, so 6 minutes equates to 360 seconds.) If the battery discharges in less than 6 minutes, the system assumes it has low storage capacity and marks it as unhealthy due to low hold time.

Typical times for a healthy battery are 6-20 minutes. If hold time falls below 6, the battery must be replaced.

Refer to page B-10 of the T3 Administrator's Guide for further details.

Q. How can I tell how old the battery is 

A. Run an 'id read' on the Power Cooling Unit ( PCU ). Here is an example:

  T3:/etc:37>id read u1pcu1
Revision             : 0000
Manufacture Week     : 00202003
Battery Install Week : 00232003
Battery Life Used    : 174 days, 9 hours
Battery Life Span    : 1095 days, 18 hours
Serial Number        : 034410
Battery Warranty Date: 20040224034126
Battery Internal Flag: 0x00000000
Vendor ID            : TECTROL-CAN
Model ID             : 300-1454-01(50)

Q. How long does the array battery last 

A. From the 'id read' output in the last question, the Battery Life Span is 1095 days or 3 years. If your array contains batteries with less than 3 years Battery Life Span please contact your local Sun office for further investigation and correction of Battery Life Span value. Original policy was to replace the battery every 2 years. Current policy is to replace any battery that fails the Health Check.

Q. How many days in advance does the array start warning about battery warranty expiration  What is a frequency of further warnings 

A. First warning is produced 45 days before warranty expiration. After the first warning is produced further warning messages are generated every 4 days.

Battery Scheduler Daemon

Each PCU contains a Nickel-Metal Hydride ( NiMH ) battery. An optimal battery contains sufficient charge to clear any uncommitted writes held in the cache in the event of lost power. The battery is a FRU and can be replaced. Originally battery life was rated at 2 years, but now batteries are only replaced on failure. In order to maintain efficacy, the battery must periodically ( every 4 weeks) be drained and recharged. This drain is monitored by the T3 to determine if the drain time is greater than 6 minutes (A healthy battery will have a drain time between 6 and 20 minutes). Once the battery falls below the minimum threshold, the array will flag the battery as being in a low condition and the battery should be replaced as soon as possible. Each of the batteries will drain and recharge sequentially. In a partner group, each PCU will drain and recharge in tandem. The cache is protected by putting the array in write-through mode during the drain portion only. A refresh will take up to 12 hours per battery.

To avoid a refresh cycle from occurring during peak activity periods, the battery scheduler daemon can be configured by editing the /etc/schd.conf or the /etc/bat.conf file on the array.

Syntax for the file is:


 BAT_BEG MM-DD-YYYY,hh-mm-ss


(where this is the start time to initiate a refresh cycle on a particular day)


 BAT_CYC 28

(where this is the number of days between refresh cycles. )

Caution: The battery service life is dependent on a battery refresh cycle of 28 days. Do not alter this value unless instructed to do so by Sun.

Note: Use the 'date' command to check the date on the array. If the date is not correct, fix the date on the array before setting the battery schedule. See InfoDoc 24715 on changing the date.

You can edit the schd.conf file by transferring through ftp from the array to a management host,  as there is no editor available in array's command line interface.  After editing, ftp the file back into the array and restart the schedule daemon by 'refresh -i'.

Here's is an example of editing /etc/schd.conf of a T3 named T3-master:

1.  cd to a directory in the host where you can temporarily store the file to be edited

$ 

cd



/var/tmp

2.  ftp the /etc/schd.conf file over to the host


$ ftp T3-master

Connected to T3-master.
220 129.147.43.44 pSOSystem FTP server (NUPPC/2.0.0-G) ready.
Name (T3-master:root):
331 Password required for root.
Password:
230 User root logged in.
ftp> 
cd /etc

250 CWD command successful.
ftp> 
get schd.conf

200 PORT command successful.
150 Opening ASCII mode data connection for schd.conf (39 bytes).
226 Transfer complete.
local: schd.conf remote: schd.conf
41 bytes received in 0.028 seconds (1.45 Kbytes/s)

3. Edit the schd.conf file.  So for our purposes, the file was edited as:

$ 
cat schd.conf

BAT_BEG 11-16-2000,01-00-00
BAT_CYC 28

4. ftp the new schd.conf back to the T3

ftp> 
put schd.conf

200 PORT command successful.
150 Opening ASCII mode data connection for schd.conf (39 bytes).
226 Transfer complete.
local: schd.conf remote: schd.conf
41 bytes received in 0.028 seconds (1.45 Kbytes/s)
ftp> 
bye

5 . The T3 is now ready to start the refresh cycle. Telnet into T3-master and check first that the PCU's are optimal.

T3-master:/:<2> 
refresh -s

No battery refreshing Task is currently running.

(As long as no refresh is in progress proceed to the next step.)

T3-master:/:<3> 
refresh -i

(This restarts the scheduler daemon and re-reads the schd.conf file.)

T3-master:/:<4> 
refresh -s

    PCU1     PCU2
-----------------------------------------------------------------
U1  Normal   Normal
U2  Normal   Normal
Current Time Sun Nov 16 16:26:51 2000
Last Refresh Fri Oct 01 13:30:50 2000
Next Refresh Fri Nov 30 01:00:00 2000

More battery-related material, for T3's, can be found in the Sun StorEdge T3 and T3+Array Installation, Operation, and Service Manual, available at:

http://www.sun.com/products-n-solutions/hardware/docs/Network_Storage_Solutions/Midrange/T3ES/index.html

and for 6120 in the Sun StorEdge 6120 Arrays System Manual, the later available at:

http://www.sun.com/products-n-solutions/hardware/docs/Network_Storage_Solutions/Midrange/6120/



Product
Sun StorageTek T3 Array
Sun StorageTek 6120 Array
Sun StorageTek T3+ Array

T3, T3+, 6120, Battery, FAQ, schedule, refresh, health check
Previously Published As
24714

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