t3MoreNotes.txt Bikle ----------------- I had an opportunity to work some more with a T3 today. What caught my attention about the T3 was an amber light which started flashing (on the leftmost side) today on the front of the T3. Yesterday it was solid green. I logged into the T3. I saw this: Escape character is '^]'. Telnet session Login: root Password: T3B Release 2.00 2001/07/12 19:35:12 (10.6.146.93) Copyright (C) 1997-2001 Sun Microsystems, Inc. All Rights Reserved. :/:<1>fru list ID TYPE VENDOR MODEL REVISION SERIAL ------ ----------------- ----------- ----------- ------------- -------- u1ctr controller card 0301 501-5710-02( 0200 105423 u1d1 disk drive u1d2 disk drive SEAGATE ST318203FSUN D44A LRG50715 u1d3 disk drive SEAGATE ST318203FSUN D44A LRG49311 u1d4 disk drive SEAGATE ST318203FSUN D44A LRC44423 u1d5 disk drive SEAGATE ST318203FSUN D44A LRG50927 u1d6 disk drive SEAGATE ST318203FSUN D94A LRK10101 u1d7 disk drive SEAGATE ST318203FSUN D44A LRG50480 u1d8 disk drive SEAGATE ST318203FSUN D44A LRG51146 u1d9 disk drive SEAGATE ST318203FSUN D44A LRG50858 u1l1 loop card SCI-SJ 375-0085-01- 5.01 Flash 008521 u1l2 loop card SCI-SJ 375-0085-01- 5.01 Flash 008514 u1pcu1 power/cooling unit TECTROL-CAN 300-1454-01( 0000 003747 u1pcu2 power/cooling unit TECTROL-CAN 300-1454-01( 0000 006875 u1mpn mid plane SLR-MI 370-3990-01- 0000 012627 :/:<2> :/:<14>fru stat CTLR STATUS STATE ROLE PARTNER TEMP ------ ------- ---------- ---------- ------- ---- u1ctr ready enabled master - 30.0 DISK STATUS STATE ROLE PORT1 PORT2 TEMP VOLUME ------ ------- ---------- ---------- --------- --------- ---- ------ u1d1 fault substituted data disk notReady notReady - dan1 u1d2 ready enabled data disk ready ready 31 dan1 u1d3 ready enabled data disk ready ready 35 dan1 u1d4 ready enabled data disk ready ready 33 dan1 u1d5 ready enabled data disk ready ready 33 dan1 u1d6 ready enabled data disk ready ready 37 dan1 u1d7 ready enabled data disk ready ready 31 dan1 u1d8 ready enabled data disk ready ready 36 dan1 u1d9 ready enabled standby ready ready 33 dan1 LOOP STATUS STATE MODE CABLE1 CABLE2 TEMP ------ ------- ---------- ------- --------- --------- ---- u1l1 ready enabled master - - 29.0 u1l2 ready enabled slave - - 31.0 POWER STATUS STATE SOURCE OUTPUT BATTERY TEMP FAN1 FAN2 ------ ------- --------- ------ ------ ------- ------ ------ ------ u1pcu1 ready enabled line normal fault normal normal normal u1pcu2 ready enabled line normal fault normal normal normal :/:<15> I noticed from the above output the word 'fault' in three places. A knowledgeable SysAdmin told me that my first drive had gone bad and that both of the batteries were in a fault status. He explained to me further that a dead battery in a T3 will hurt its performance. A T3 with a dead pair of batteries will not automatically make use of its cache; instead, writes will go directly to disk which is a slower way to write. He also pointed out that a dead battery can be detected by any DBA who looks at the back of the T3. If the battery or batteries are dead, an amber light will light up next to one (or both) of the power buttons. I looked at the back of my T3 and sure enough I saw two amber lights next to the power buttons. It was then that I noticed another T3. It too had two amber lights next to the power buttons. This particular T3 had caught my attention earlier in the week because an iostat session had told me that this T3 was writing data at 1/3 the rate of another T3 when being pushed at 100%. So, the mystery at it's poor performance had just been solved for me. I logged into this T3. Here is what I saw: Login: root Password: T3B Release 2.00 2001/07/12 19:35:12 (10.6.146.94) Copyright (C) 1997-2001 Sun Microsystems, Inc. All Rights Reserved. :/:<1> :/:<1> :/:<1>sys list blocksize : 64k cache : auto mirror : auto mp_support : none naca : off rd_ahead : on recon_rate : med sys memsize : 128 MBytes cache memsize : 1024 MBytes :/:<2>fru list ID TYPE VENDOR MODEL REVISION SERIAL ------ ----------------- ----------- ----------- ------------- -------- u1ctr controller card 0301 501-5710-02( 0200 105164 u1d1 disk drive SEAGATE ST318203FSUN D94A LRH42700 u1d2 disk drive SEAGATE ST318203FSUN D94A LRH48689 u1d3 disk drive SEAGATE ST318203FSUN D94A LRH46756 u1d4 disk drive SEAGATE ST318203FSUN D94A LRG93945 u1d5 disk drive SEAGATE ST318203FSUN D94A LRH48518 u1d6 disk drive SEAGATE ST318203FSUN D94A LRH47075 u1d7 disk drive SEAGATE ST318203FSUN D94A LRH48827 u1d8 disk drive SEAGATE ST318203FSUN D94A LRH47650 u1d9 disk drive SEAGATE ST318203FSUN D94A LRH48561 u1l1 loop card SCI-SJ 375-0085-01- 5.01 Flash 007539 u1l2 loop card SCI-SJ 375-0085-01- 5.01 Flash 007207 u1pcu1 power/cooling unit TECTROL-CAN 300-1454-01( 0000 012114 u1pcu2 power/cooling unit TECTROL-CAN 300-1454-01( 0000 012107 u1mpn mid plane SLR-MI 370-3990-01- 0000 012692 :/:<3>fru stat CTLR STATUS STATE ROLE PARTNER TEMP ------ ------- ---------- ---------- ------- ---- u1ctr ready enabled master - 30.5 DISK STATUS STATE ROLE PORT1 PORT2 TEMP VOLUME ------ ------- ---------- ---------- --------- --------- ---- ------ u1d1 ready enabled data disk ready ready 36 dan1 u1d2 ready enabled data disk ready ready 40 dan1 u1d3 ready enabled data disk ready ready 36 dan1 u1d4 ready enabled data disk ready ready 38 dan1 u1d5 ready enabled data disk ready ready 36 dan1 u1d6 ready enabled data disk ready ready 34 dan1 u1d7 ready enabled data disk ready ready 37 dan1 u1d8 ready enabled data disk ready ready 31 dan1 u1d9 ready enabled standby ready ready 30 dan1 LOOP STATUS STATE MODE CABLE1 CABLE2 TEMP ------ ------- ---------- ------- --------- --------- ---- u1l1 ready enabled master - - 29.5 u1l2 ready enabled slave - - 33.0 POWER STATUS STATE SOURCE OUTPUT BATTERY TEMP FAN1 FAN2 ------ ------- --------- ------ ------ ------- ------ ------ ------ u1pcu1 ready enabled line normal fault normal normal normal u1pcu2 ready enabled line normal fault normal normal normal :/:<4>sys usage: sys list sys stat sys blocksize <16k | 32k | 64k> sys cache sys mirror sys mp_support sys naca sys rd_ahead sys recon_rate :/:<5>sys cache writebehind ERROR (200025) VN_MIRRORON: cannot change cache mode when mirroring is on :/:<6> sys mirror off :/:<7> sys cache writebehind :/:<8>sys list blocksize : 64k cache : writebehind mirror : off mp_support : none naca : off rd_ahead : on recon_rate : med sys memsize : 128 MBytes cache memsize : 1024 MBytes :/:<9> The above output shows how I had used the sys command to change some attributes of the T3. Enabling the writebehind cache will boost performance of writes. The idea is simple; when data comes into the T3 it gets written very quickly to a cache (which should be battery protected from power failure). Eventually the T3 will flush the cache to disk. The DBA needs to be aware, though, that Sun designed the T3 to disable the cache if the batteries go dead. If you are brave, you may override this default behavior by issuing the command: 'sys cache writebehind'. I later found out that a blocksize of 64k would be suitable for a T3 which supports a DSS database. Obviously, a blocksize of 16k would be suitable for a T3 which supports an OLTP database.