Duo V2: Resync after every start up

Are you using drives that are found on the Hardware Compatibility List?

Has this been happening since day one? or has this started recently?

Have you opened a support ticket?
Even if you are out of warranty, they will help you here www.readynas.com/support

If you have already opened a support ticket, please edit the title of the thread to contain the ticket number.

Yes, I am using 2x Spinpoints F4 HD204UI...

Actually I have quite a history with this device :) This is already second (replaced) unit. I returned the first one due the death after enabled power timer. Now I got replacement, upgraded to RAIDiatror 5.3.4 (which should resolve previous bug) and from the beginning never switched it off. But since the device is in my living room I finally enabled power timer again and noticed this issue. I am using the same disks form the first unit. BTW tried to switch 1 an 2 disk, after what the same disk is being resynced.. I mean before this, disk 2 was recynced, after I switched them, now disk 1 (same physical disk) is being resynced. Maybe I need to remove that disk and wipe it on PC?

No support ticket yet...

The problem moves with the disk, and in two different NAS and in different slots. An identical disk doesn't resync in the same equipment.

I am thinking you have a marginal disk drive. Do you see any i/o errors in the log? Have you looked at the smart stats, etc?

BTW, if you do hook it up on your PC you can see SMART stats with several free tools. Western Digital's Lifeguard diag will show this info for any drive, as will Acronis Drive Monitor, and several others.

I didn't have this problem with the first NAS, there was different problem...

I would still look for disk errors in the logs and check disk health.

Download your logs (On the Dashboard, click Configure, then select Health > Logs > Download Logs). Extract the zip contents and look at disk_smart.log. What does the disk health look like?

You may also wish to run the "Disk Test" boot option: http://www.readynas.com/kb/faq/boot/how_do_i_use_the_boot_menu

Checking disk_smart.log (see below), don't see any errors... :/

***** Disk SMART log from 2012/04/29 ***** ***** Disk SMART log for channel 1 [sda] ***** smartctl 5.40 2010-07-12 r3124 [armv5tel-unknown-linux-gnueabi] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Device Model: SAMSUNG HD204UI Serial Number: S2H7J9GB910334 Firmware Version: 1AQ10001 User Capacity: 2,000,398,934,016 bytes Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 6 Local Time is: Sun Apr 29 06:47:03 2012 EEST 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: (20280) seconds. Offline data collection capabilities: (0x5b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. 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: ( 255) minutes. SCT capabilities: (0x003f) SCT Status supported. SCT Error Recovery Control 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 100 100 051 Pre-fail Always - 0 2 Throughput_Performance 0x0026 252 252 000 Old_age Always - 0 3 Spin_Up_Time 0x0023 068 065 025 Pre-fail Always - 9952 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 227 5 Reallocated_Sector_Ct 0x0033 252 252 010 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 252 252 051 Old_age Always - 0 8 Seek_Time_Performance 0x0024 252 252 015 Old_age Offline - 0 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 629 10 Spin_Retry_Count 0x0032 252 252 051 Old_age Always - 0 11 Calibration_Retry_Count 0x0032 252 252 000 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 27 181 Program_Fail_Cnt_Total 0x0022 100 100 000 Old_age Always - 357372 191 G-Sense_Error_Rate 0x0022 100 100 000 Old_age Always - 3 192 Power-Off_Retract_Count 0x0022 252 252 000 Old_age Always - 0 194 Temperature_Celsius 0x0002 064 063 000 Old_age Always - 27 (Lifetime Min/Max 16/37) 195 Hardware_ECC_Recovered 0x003a 100 100 000 Old_age Always - 0 196 Reallocated_Event_Count 0x0032 252 252 000 Old_age Always - 0 197 Current_Pending_Sector 0x0032 252 252 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 252 252 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0036 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x002a 100 100 000 Old_age Always - 1 223 Load_Retry_Count 0x0032 252 252 000 Old_age Always - 0 225 Load_Cycle_Count 0x0032 100 100 000 Old_age Always - 231 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% 0 - Note: selective self-test log revision number (0) not 1 implies that no selective self-test has ever been run SMART Selective self-test log data structure revision number 0 Note: revision number not 1 implies that no selective self-test has ever been run SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS 1 0 0 Completed [00% left] (0-65535) 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. ***** Disk SMART log for channel 2 [sdb] ***** smartctl 5.40 2010-07-12 r3124 [armv5tel-unknown-linux-gnueabi] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Device Model: SAMSUNG HD204UI Serial Number: S2H7J9AB200936 Firmware Version: 1AQ10001 User Capacity: 2,000,398,934,016 bytes Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 6 Local Time is: Sun Apr 29 06:47:09 2012 EEST 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: (20520) seconds. Offline data collection capabilities: (0x5b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. 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: ( 255) minutes. SCT capabilities: (0x003f) SCT Status supported. SCT Error Recovery Control 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 100 100 051 Pre-fail Always - 19 2 Throughput_Performance 0x0026 252 252 000 Old_age Always - 0 3 Spin_Up_Time 0x0023 067 067 025 Pre-fail Always - 10092 4 Start_Stop_Count 0x0032 099 099 000 Old_age Always - 1028 5 Reallocated_Sector_Ct 0x0033 252 252 010 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 252 252 051 Old_age Always - 0 8 Seek_Time_Performance 0x0024 252 252 015 Old_age Offline - 0 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 2926 10 Spin_Retry_Count 0x0032 252 252 051 Old_age Always - 0 11 Calibration_Retry_Count 0x0032 252 252 000 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 779 181 Program_Fail_Cnt_Total 0x0022 100 100 000 Old_age Always - 289614 191 G-Sense_Error_Rate 0x0022 100 100 000 Old_age Always - 21 192 Power-Off_Retract_Count 0x0022 252 252 000 Old_age Always - 0 194 Temperature_Celsius 0x0002 064 064 000 Old_age Always - 27 (Lifetime Min/Max 11/60) 195 Hardware_ECC_Recovered 0x003a 100 100 000 Old_age Always - 0 196 Reallocated_Event_Count 0x0032 252 252 000 Old_age Always - 0 197 Current_Pending_Sector 0x0032 252 252 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 252 252 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0036 100 100 000 Old_age Always - 96 200 Multi_Zone_Error_Rate 0x002a 100 100 000 Old_age Always - 7 223 Load_Retry_Count 0x0032 252 252 000 Old_age Always - 0 225 Load_Cycle_Count 0x0032 100 100 000 Old_age Always - 1129 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] Note: selective self-test log revision number (0) not 1 implies that no selective self-test has ever been run SMART Selective self-test log data structure revision number 0 Note: revision number not 1 implies that no selective self-test has ever been run SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS 1 0 0 Completed [00% left] (0-65535) 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.