I'm suddenly seeing some strange behaviour on our USB backup drive that doesn't make sense to me:
(2013-10-21 14:58:23 [root@newdc /]$ cd /mnt/backup/ (2013-10-21 14:59:03 [root@newdc backup]$ ls -la ls: reading directory .: Input/output error total 0 (2013-10-21 14:59:05 [root@newdc backup]$ df -h /mnt/backup Filesystem Size Used Avail Use% Mounted on /dev/sda1 917G 843G 28G 97% /mnt/backup
How is it possible for the OS to know how much is in use, but I can't
ls any of it as root? Or more to the point, what problem does this indicate?
/var/log/messages said this:
Oct 21 14:57:54 g5 kernel: EXT4-fs error (device sda1): ext4_journal_start_sb: Detected aborted journal Oct 21 14:57:54 g5 kernel: EXT4-fs (sda1): Remounting filesystem read-only
But...read-only is something different than 'throw an io error'...
After unmounting to try fsck on it, I had someone on-site look at it, and the drive was not spun up, and had a slow-flashing light, which I believe means it was in a power-suspend mode. So I had them unplug and replug the USB cable, and now (before remounting) it says:
fsck from util-linux-ng 2.17.2 e2fsck 1.41.12 (17-May-2010) /dev/sda1: clean, 2805106/61046784 files, 181934167/244182016 blocks
I then mount it and now
ls works and
Filesystem Size Used Avail Use% Mounted on /dev/sda1 917G 680G 191G 79% /mnt/backup
What would cause it to go into such a state without being asked to? Why all the weird behaviour, and now it appears to not be corrupt?
smartctl 5.43 2012-06-30 r3573 [x86_64-linux-2.6.32-358.11.1.el6.x86_64] (local build) Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Device Model: WDC WD10JMVW-11S5XS0 Serial Number: WD-WX51AC2X2298 LU WWN Device Id: 5 0014ee 6587c0e18 Firmware Version: 01.01A01 User Capacity: 1,000,204,886,016 bytes [1.00 TB] Sector Sizes: 512 bytes logical, 4096 bytes physical Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Wed Oct 23 20:08:46 2013 EDT SMART support is: Available - device has SMART capability. SMART support is: Enabled === START OF READ SMART DATA SECTION === SMART STATUS RETURN: incomplete response, ATA output registers missing SMART overall-health self-assessment test result: PASSED Warning: This result is based on an Attribute check. 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: (18180) 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: ( 2) minutes. Extended self-test routine recommended polling time: ( 198) minutes. Conveyance self-test routine recommended polling time: ( 5) minutes. SCT capabilities: (0x70b5) SCT Status supported. SCT Feature Control supported. SCT Data Table supported. SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0 3 Spin_Up_Time 0x0027 188 179 021 Pre-fail Always - 1600 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 940 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always - 0 9 Power_On_Hours 0x0032 098 098 000 Old_age Always - 2004 10 Spin_Retry_Count 0x0032 100 100 000 Old_age Always - 0 11 Calibration_Retry_Count 0x0032 100 100 000 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 744 192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 12 193 Load_Cycle_Count 0x0032 197 197 000 Old_age Always - 9379 194 Temperature_Celsius 0x0022 115 098 000 Old_age Always - 32 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 100 253 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 100 253 000 Old_age Offline - 0 SMART Error Log Version: 1 No Errors Logged SMART Self-test log structure revision number 1 No self-tests have been logged. [To run self-tests, use: smartctl -t] 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.
Interestingly, no errors are logged, even after an extended test apparently aborted spontaneously:
$ sudo smartctl -l error /dev/sda smartctl 5.43 2012-06-30 r3573 [x86_64-linux-2.6.32-358.11.1.el6.x86_64] (local build) Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net === START OF READ SMART DATA SECTION === SMART Error Log Version: 1 No Errors Logged