最近幾天我一直在用一些地圖創建一些 PNG 圖像（使用 R）。圖像完成後，我將它們移動到標有“ok”的單獨資料夾中，這樣我就不會面臨以後覆蓋它們的風險。然而，其中一些圖像幾天后變得完全白色，其他圖像則返回到之前的狀態（上面只有幾層形狀文件），我什至不確定我是否在某個時刻生成了這些圖像（我想我做到了，因為我對其中一些人這樣做了）。即使白色影像也保留其實際大小（以位元組為單位），儘管它們在許多程式中顯示為完全白色。
pngcheck談到其中一張圖像，一張全白的圖像 - 假設檔名是file.png：
file.png additional data after IEND chunk
ERROR: file.png
使用 ImageMagick 對相同檔案運行直方圖會回傳：
convert file.png -define histogram:unique-colors=true -format %c histogram:info:-
9000000: (255,255,255) #FFFFFF white
這意味著它真的變成了全白（原始圖像是 3000x3000 像素）。
我使用的是 Debian 9。
Disk is OK, 43 bad sectors.
現在我又進行了同樣的測試，結果還是一樣。這應該意味著沒有出現新的壞扇區。這是普通的 HDD，而不是 SSD。這是完整的輸出：
以及結果smartctl -a：
smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.9.0-9-amd64] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Seagate Constellation ES (SATA)
Device Model: ST32000644NS
Serial Number: 9WM0CKBJ
LU WWN Device Id: 5 000c50 01a8899f1
Firmware Version: GG15
User Capacity: 2,000,398,934,016 bytes [2.00 TB]
Sector Size: 512 bytes logical/physical
Rotation Rate: 7200 rpm
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 2.6, 3.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Tue Jun 4 23:23:48 2019 -03
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: ( 609) 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: ( 339) minutes.
Conveyance self-test routine
recommended polling time: ( 2) minutes.
SCT capabilities: (0x10bd) SCT Status supported.
SCT Error Recovery Control 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 075 063 044 Pre-fail Always - 32950755
3 Spin_Up_Time 0x0003 100 100 000 Pre-fail Always - 0
4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 976
5 Reallocated_Sector_Ct 0x0033 099 099 036 Pre-fail Always - 43
7 Seek_Error_Rate 0x000f 081 060 030 Pre-fail Always - 130556579
9 Power_On_Hours 0x0032 080 080 000 Old_age Always - 17849
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 975
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 098 098 000 Old_age Always - 2
190 Airflow_Temperature_Cel 0x0022 059 047 045 Old_age Always - 41 (Min/Max 24/42)
191 G-Sense_Error_Rate 0x0032 100 100 000 Old_age Always - 1
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 31
193 Load_Cycle_Count 0x0032 100 100 000 Old_age Always - 977
194 Temperature_Celsius 0x0022 041 053 000 Old_age Always - 41 (0 18 0 0 0)
195 Hardware_ECC_Recovered 0x001a 024 018 000 Old_age Always - 32950755
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
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% 17849 -
# 2 Short offline Completed without error 00% 15687 -
# 3 Extended offline Aborted by host 50% 14014 -
# 4 Extended offline Aborted by host 90% 13928 -
# 5 Short offline Completed without error 00% 13928 -
# 6 Short offline Completed without error 00% 13927 -
# 7 Short offline Aborted by host 80% 13927 -
# 8 Short offline Completed without error 00% 2881 -
# 9 Short offline Completed without error 00% 2878 -
#10 Short offline Completed without error 00% 1562 -
#11 Short offline Completed without error 00% 151 -
#12 Short offline Completed without error 00% 48 -
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.
可能發生了什麼事？