前言
今天查看集群，发现写入速度明显下降了。
Virtual Drive: 4 (Target Id: 4)
Name :
RAID Level : Primary-5, Secondary-0, RAID Level Qualifier-3
Size : 32.743 TB
Sector Size : 512
Is VD emulated : No
Parity Size : 3.637 TB
State : Optimal
Strip Size : 128 KB
Number Of Drives : 10
Span Depth : 1
Default Cache Policy: WriteBack, ReadAdaptive, Cached, No Write Cache if Bad BBU
Current Cache Policy: WriteBack, ReadAdaptive, Cached, No Write Cache if Bad BBU
Default Access Policy: Read/Write
Current Access Policy: Read/Write
Disk Cache Policy : Disabled
Ongoing Progresses:
Check Consistency : Completed 4%, Taken 616 min.
Encryption Type : None
Bad Blocks Exist: No
PI type: No PI
Is VD Cached: No
Exit Code: 0x00
发现集群中的RAID在做一致性检查。
LSI MegaRaid的一致性检查分成两种
- Patrol Read
- Consistency Check
本文介绍Consistency Check。其相关的几个参数如下：
- Delay Interval： 默认是168小时，即一周。
- mode ： 值有两种 并发模式 ModeConc 和顺序模式ModeSeq
- Consistency Check Rate ： 默认30%
查看当前配置
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCCSched -Info -Aall
Adapter #0
Operation Mode: Concurrent
Execution Delay: 168
Next start time: 08/13/2016, 10:00:
Current State: Active
Number of iterations: 0
Number of VD completed: 0
Excluded VDs : None
Exit Code: 0x00
root@IPTV:~# date
Sun Aug 14 19:31:13 CST 2016
设置下次周期性一致性检查的时间
因为周期性检查会损害性能，所以正常使用过程中如果进行这个检查会造成性能显著地下降。因此我们一般有需要调整周期行检查的时间和周期。
设置RAID Controller的时间
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpSetTime `date +%Y%m%d` `date +%H:%M:%S` -Aall -NoLOG
New date/time is set on Adapter 0
Exit Code: 0x00
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpGetTime -Aall
Adapter 0:
Date: 08/14/2016
Time: 19:35:46
Exit Code: 0x00
设置下次检查的时间
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -SetStartTime 20160830 02 -Aall
Adapter 0: Scheduled CC start time is set.
Exit Code: 0x00
设置完毕后，通过如下命令查看是否生效：
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -Info -Aall
Adapter #0
Operation Mode: Concurrent
Execution Delay: 168
Next start time: 08/30/2016, 02:00:00
Current State: Active
Number of iterations: 0
Number of VD completed: 0
Excluded VDs : None
Exit Code: 0x00
root@IPTV:~#
设置检查周期
默认检查周期是168小时，即7天的时间。可以将检查周期变成30天，如下所示：
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -SetDelay 720 -Aall
Adapter 0: Scheduled CC execution delay is set to 720 hours.
Exit Code: 0x00
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -Info -Aall
Adapter #0
Operation Mode: Concurrent
Execution Delay: 720
Next start time: 08/30/2016, 02:00:00
Current State: Active
Number of iterations: 0
Number of VD completed: 0
Excluded VDs : None
Exit Code: 0x00
root@IPTV:~#
检查进度
如果已经在进行一致性检查了，可能希望了解当前的进度，包括什么时候开始的检查。
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -ldcc -progdsply -lall -aall
Progress of Virtual Drives...
Virtual Drive # Percent Complete Time Elps
3 ## 04 % 11:46:53
4 ## 04 % 13:13:39
Press <ESC> key to quit...
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -ldcc -showprog -lall -aall
Check Consistency on VD #0 is not in progress.
Check Consistency on VD #3 (target id #3) Completed 4% in 808 Minutes.
Check Consistency on VD #4 (target id #4) Completed 4% in 840 Minutes.
Exit Code: 0x00
禁止一致性检查
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -Dsbl -Aall
Adapter 0: Scheduled CC mode is set to Disabled.
Exit Code: 0x00
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -Info -Aall
Adapter #0
Operation Mode: Disabled
Execution Delay: 720
Next start time: 07/28/2135, 02:00:00
Current State: Active
Number of iterations: 0
Number of VD completed: 0
Excluded VDs : None
Exit Code: 0x00
root@IPTV:~#
设置模式
设置为ModeConc
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -ModeConc -Aall
Adapter 0: Scheduled CC mode is set to Concurrent.
Exit Code: 0x00
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCCSched -Info -Aall
Adapter #0
Operation Mode: Concurrent
Execution Delay: 168
Next start time: 07/28/2135, 02:00:00
Current State: Active
Number of iterations: 0
Number of VD completed: 0
Excluded VDs : None
Exit Code: 0x00
root@IPTV:~#
设置为顺序模式：
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -ModeSeq -Aall
Adapter 0: Scheduled CC mode is set to Sequential.
Exit Code: 0x00
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpCcSched -Info -Aall
Adapter #0
Operation Mode: Sequential
Execution Delay: 720
Next start time: 07/28/2135, 02:00:00
Current State: Active
Number of iterations: 0
Number of VD completed: 0
Excluded VDs : None
Exit Code: 0x00
注意，如果Disable了一致性检查，然后设置mode，需要设置下一次检查的时间，否则时间为2135年07月28日。
设置Consistency Check Rate
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 AdpGetProp CCRate -Aall
Adapter 0: Check Consistency Rate = 30%
Exit Code: 0x00
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 -AdpSetprop CCRate 10 -A0
Adapter 0: Set Check consistency rate to 10% success.
Exit Code: 0x00
root@IPTV:~# /opt/MegaRAID/MegaCli/MegaCli64 AdpGetProp CCRate -Aall
Adapter 0: Check Consistency Rate = 10%
Exit Code: 0x00