過去数日間、私はいくつかの地図を含むPNG画像（Rを使用して）を作成してきました。画像が完成したら、後で上書きする危険がないように、「ok」とマークされた別のフォルダに移動します。ただし、これらの画像の一部は数日後に完全に白くなり、他の画像は以前の状態に戻り（一番上にいくつかの図形ファイルレイヤーしかありません）、どの時点でこれらの画像を作成したかさえわかりません。私はそれらのいくつかにそれをしたので到着したと思います）。白い画像も、多くのプログラムで完全に白く見えても、実際のサイズ（バイト）を維持します。
pngcheckイメージの1つである完全に白いイメージについて話しましょう。ファイル名は次のとおりですfile.png。
file.png additional data after IEND chunk
ERROR: file.png
ImageMagickを使用して同じファイルでヒストグラムを実行すると、次のものが返されます。
convert file.png -define histogram:unique-colors=true -format %c histogram:info:-
9000000: (255,255,255) #FFFFFF white
これは実際には完全に白になることを意味します（元の画像は3000×3000ピクセルでした）。
私はDebian 9を使用しています。前回、このHD（gnome-disksを使用）でセルフテストを実行したとき、私は次のように言いました。
Disk is OK, 43 bad sectors.
これで同じテストを再実行しましたが、結果はまだ同じでした。これは、新しい不良セクタが現れなかったことを意味します。 SSDではなく、通常のHDDです。全体の出力は次のとおりです。
結果は次のとおりです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.
何が起こりましたか？