Changes between Initial Version and Version 1 of awbRaid


Ignore:
Timestamp:
01/26/24 11:26:55 (23 months ago)
Author:
niles
Comment:

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  • awbRaid

    v1 v1  
     1== Always Write Back is good, Write Through is bad == 
     2 
     3I'm not even sure what that means but I found out when setting up the LSI RAIDs on 
     4vso04 and vso05. Here are the notes : 
     5 
     6{{{ 
     7 
     8# /opt/MegaRAID/storcli/storcli64 /c0 show 
     9 
     10This showed, in part : 
     11 
     12VD LIST : 
     13======= 
     14 
     15---------------------------------------------------------------- 
     16DG/VD TYPE  State Access Consist Cache Cac sCC       Size Name   
     17---------------------------------------------------------------- 
     181/238 RAID6 Optl  RW     Yes     RWTD  -   ON  127.329 TB RAID6  
     190/239 RAID1 Optl  RW     Yes     RWTD  -   ON    1.745 TB RAID1  
     20---------------------------------------------------------------- 
     21 
     22That WT means "Write Through" - this is apparently bad and wrong. 
     23We want "Always Write Back" instead. So do this : 
     24 
     25# /opt/MegaRAID/storcli/storcli64 /c0/v238 set wrcache=awb 
     26# /opt/MegaRAID/storcli/storcli64 /c0/v239 set wrcache=awb 
     27 
     28Which looks like this when executed : 
     29 
     30# /opt/MegaRAID/storcli/storcli64 /c0/v238 set wrcache=awb 
     31CLI Version = 007.2309.0000.0000 Sep 16, 2022 
     32Operating system = Linux 4.18.0-513.9.1.el8_9.x86_64 
     33Controller = 0 
     34Status = Success 
     35Description = None 
     36 
     37Detailed Status : 
     38=============== 
     39 
     40---------------------------------------- 
     41 VD Property Value Status  ErrCd ErrMsg  
     42---------------------------------------- 
     43238 wrCache  AWB   Success     0 -       
     44---------------------------------------- 
     45 
     46# /opt/MegaRAID/storcli/storcli64 /c0/v239 set wrcache=awb 
     47CLI Version = 007.2309.0000.0000 Sep 16, 2022 
     48Operating system = Linux 4.18.0-513.9.1.el8_9.x86_64 
     49Controller = 0 
     50Status = Success 
     51Description = None 
     52 
     53Detailed Status : 
     54=============== 
     55 
     56---------------------------------------- 
     57 VD Property Value Status  ErrCd ErrMsg  
     58---------------------------------------- 
     59239 wrCache  AWB   Success     0 -       
     60---------------------------------------- 
     61 
     62 
     63The "show" command : 
     64# /opt/MegaRAID/storcli/storcli64 /c0 show 
     65now looks, in part, like this : 
     66 
     67VD LIST : 
     68======= 
     69 
     70---------------------------------------------------------------- 
     71DG/VD TYPE  State Access Consist Cache Cac sCC       Size Name   
     72---------------------------------------------------------------- 
     731/238 RAID6 Optl  RW     Yes     RAWBD -   ON  127.329 TB RAID6  
     740/239 RAID1 Optl  RW     Yes     RAWBD -   ON    1.745 TB RAID1  
     75---------------------------------------------------------------- 
     76 
     77This is apparently a vast improvement. 
     78 
     79}}}