Re: LGWR, EMC or app cursors?
Date: Mon, 7 Oct 2019 18:56:15 -0400
Message-ID: <205aabe1-1a37-1fda-b082-f12fadba8a35_at_gmail.com>
On 10/7/19 11:17 AM, Herring, David (Redacted sender HerringD for DMARC) wrote:
> > I am stuck trying to find out, really prove who is the culprit or what > exactly the wait is on. Is LGWR waiting on user sessions and user > sessions are waiting on LGWR and all that causes the disk to be 100%? > Can I enable some sort of tracing on LGWR and would that point to > exactly what he's waiting on to prove where the problem is? > > Regards, > > Dave >
Hi Dave!
Is there anything in /var/log/messages? Can you check disks using smartctl? That should look something like this:
root_at_umajor:~# smartctl -a /dev/sda
smartctl 6.6 2017-11-05 r4594 [x86_64-linux-5.0.0-32-generic] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org
- START OF INFORMATION SECTION === Device Model: Samsung SSD 860 QVO 2TB Serial Number: S4PHNF0M200370J LU WWN Device Id: 5 002538 e40d20892 Firmware Version: RVQ01B6Q User Capacity: 2,000,398,934,016 bytes [2.00 TB] Sector Size: 512 bytes logical/physical Rotation Rate: Solid State Device Form Factor: 2.5 inches Device is: Not in smartctl database [for details use: -P showall] ATA Version is: ACS-4 T13/BSR INCITS 529 revision 5 SATA Version is: SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s) Local Time is: Mon Oct 7 18:52:18 2019 EDT SMART support is: Available - device has SMART capability. SMART support is: Enabled
- START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x00) Offline data collection activity
was never started.
Auto Offline Data Collection: Disabled.
Self-test execution status: ( 0) The previous self-test
routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: ( 0) seconds.
Offline data collection
capabilities: (0x53) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
No Offline surface scan supported.
Self-test supported.
No Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 2) minutes. Extended self-test routine
recommended polling time: ( 160) minutes.
SCT capabilities: (0x003d) SCT Status supported.SCT Feature Control supported.
SCT Error Recovery Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE
UPDATED WHEN_FAILED RAW_VALUE
5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail
Always - 0
9 Power_On_Hours 0x0032 099 099 000 Old_age
Always - 2110
12 Power_Cycle_Count 0x0032 099 099 000 Old_age
Always - 550
177 Wear_Leveling_Count 0x0013 099 099 000 Pre-fail Always - 2
179 Used_Rsvd_Blk_Cnt_Tot 0x0013 100 100 010 Pre-fail Always - 0
181 Program_Fail_Cnt_Total 0x0032 100 100 010 Old_age Always - 0
182 Erase_Fail_Count_Total 0x0032 100 100 010 Old_age Always
See if you can decipher anything from the smartctl output.
-- Mladen Gogala Database Consultant Tel: (347) 321-1217 -- http://www.freelists.org/webpage/oracle-lReceived on Tue Oct 08 2019 - 00:56:15 CEST