I just bought a SSD to replace the HDD in my laptop (Dell Inspiron 15 3521).
So I migrated the windows partition, root partition of Ubuntu, and make a bcache caching partition for /home
which stays on the HDD.
The HDD is now in a HDD caddy inside the DVD drive place.
So the problem is my HDD (?) start sometimes to make ticking noise (but not a clicking one), like a watch but a little louder, every second or half a second, repeatedly and continuously.
Not only this is annoying, but I fear for the health of the HDD.
It is particularly strange given that with my new setup the access to the HDD is limited. What still on HDD is /var
partition and a swap but I have 8G of RAM. and the backing bcache /home
partition.
I thought it could be the head of HDD parking repeatedly. But a simple script found on the net shows no change in Load_Cycle_Count value from smartctl -a /dev/sdb
output
The worrying value that keep increasing is Raw_Read_Error_Rate but it is said to be meaningless for Seagate HDD (here ST500LT012)
Even when I switch to console and stop lightdm, that sound continue.
But if I run a short self-test with gsmartcontrol, that sounds suddenly stops. The short self-test passed without error. I run badblocks on /home
backing bcache partition and no errors were found.
I don't know what cause that sound. It does not seem to be a process hammering the HDD. I run only chromium and a terminal
Output of smartctl -a:
$ smartctl -a /dev/sdb
smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.16.0-31-generic] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Device Model: ST500LT012-1DG142
Serial Number: XXXXXXXX
LU WWN Device Id: 5 000c50 xxxxxxxxxx
Firmware Version: 0001SDM1
User Capacity: 500 107 862 016 bytes [500 GB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Sat Mar 21 01:12:10 2015 CET
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: (0x82) Offline data collection activity
was completed without error.
Auto Offline Data Collection: Enabled.
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: (0x7b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
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: ( 1) minutes.
Extended self-test routine
recommended polling time: ( 103) minutes.
Conveyance self-test routine
recommended polling time: ( 2) minutes.
SCT capabilities: (0x1035) SCT Status supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 10
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000f 119 099 006 Pre-fail Always - 226511072
3 Spin_Up_Time 0x0003 100 099 000 Pre-fail Always - 0
4 Start_Stop_Count 0x0032 099 099 020 Old_age Always - 1883
5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 076 060 030 Pre-fail Always - 47056689
9 Power_On_Hours 0x0032 098 098 000 Old_age Always - 2357 (113 43 0)
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 099 099 020 Old_age Always - 1582
184 End-to-End_Error 0x0032 100 100 099 Old_age Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0
188 Command_Timeout 0x0032 100 100 000 Old_age Always - 0
189 High_Fly_Writes 0x003a 100 100 000 Old_age Always - 0
190 Airflow_Temperature_Cel 0x0022 079 048 045 Old_age Always - 21 (Min/Max 19/21)
191 G-Sense_Error_Rate 0x0032 100 100 000 Old_age Always - 100
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 46
193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 3935
194 Temperature_Celsius 0x0022 021 052 000 Old_age Always - 21 (0 11 0 0 0)
197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0
240 Head_Flying_Hours 0x0000 098 098 000 Old_age Offline - 156817845913887
241 Total_LBAs_Written 0x0000 100 253 000 Old_age Offline - 6713158176
242 Total_LBAs_Read 0x0000 100 253 000 Old_age Offline - 8448037256
254 Free_Fall_Sensor 0x0032 100 100 000 Old_age Always - 0
SMART Error Log Version: 1
No Errors Logged
SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Short offline Completed without error 00% 2354 -
# 2 Short offline Completed without error 00% 2342 -
# 3 Short offline Completed without error 00% 2339 -
# 4 Short offline Completed without error 00% 2334 -
# 5 Short offline Completed without error 00% 2333 -
# 6 Short offline Completed without error 00% 2307 -
# 7 Short offline Completed without error 00% 2306 -
# 8 Short offline Completed without error 00% 2295 -
# 9 Short offline Completed without error 00% 2295 -
#10 Short offline Completed without error 00% 2291 -
#11 Short offline Completed without error 00% 2283 -
#12 Short offline Completed without error 00% 1198 -
#13 Extended offline Completed without error 00% 937 -
#14 Short offline Completed without error 00% 935 -
#15 Short offline Completed without error 00% 356 -
#16 Extended offline Completed without error 00% 122 -
#17 Short offline Completed without error 00% 120 -
#18 Short offline Completed without error 00% 14 -
#19 Short offline Completed without error 00% 0 -
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.
I'm having the same issue. Is (was?) bcache in writeback mode?
In writeback mode, bcache keeps a buffer of so-called dirty data on the cache. By default, this is 10% of the cache size. It does this to collect sequential data to write to the backing device, since HDDs are good at sequential IO (see koverstreet's post from May 15, 2012 3:43 UTC at this link).
For me, the clicking sound stops when I disable this buffer as so:
I've asked a question about why this happens on superuser here. If there's no response, I'll file a bug report!