SMART raw read error

[jim71]

Hi,

I am currently installing an N4F with 4 WD Red 3TB in geom raid 5. 3 HDD comes from a previous installation and are not new (but not that old),
and one is new. Looking at the smart values of the disks I found that one of the old ones has some raw read error:

=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red (AF)
Device Model: WDC WD30EFRX-68AX9N0
Serial Number: WD-xxxxxxxx
LU WWN Device Id: 5 0014ee 6add7cfde
Firmware Version: 80.00A80
User Capacity: 3,000,592,982,016 bytes [3.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Device is: In smartctl database [for details use: -P show]
ATA Version is: ACS-2 (minor revision not indicated)
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Sun Mar 23 14:08:43 2014 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled


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 199 199 051 Pre-fail Always - 4029
3 Spin_Up_Time 0x0027 186 184 021 Pre-fail Always - 5666
4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 900
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 088 088 000 Old_age Always - 9341
10 Spin_Retry_Count 0x0032 100 100 000 Old_age Always - 0
11 Calibration_Retry_Count 0x0032 100 253 000 Old_age Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 53
192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 38
193 Load_Cycle_Count 0x0032 200 200 000 Old_age Always - 861
194 Temperature_Celsius 0x0022 116 114 000 Old_age Always - 34
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


For the others disks, two are at 0 and one at 1 error. So I was wondering if I should worry about this disk and consider
exchanging it ?

Note that the ammount is raising continiously. In now about 2 hours of raid building it passes rougthly from 3000 to 4000 errors.

Also is it normal to have a so big time for raid 5 building ? After 2 hours I am only at 1.68%, estimated time 8000min !!
Which will do possibily about 70k errors.

[kenZ71]

Western Digital has some great tools that allow you to scan a disk. If errors are found the tool generates a RMA.

You might need to move the drive to Windows or Linux machine for the scan.

[b0ssman]

run a badblocks scan on it.

badblocks -wvsb 4096 /dev/<drive>

warning this will erase all data.

then check the smart values again

[jim71]

I tried a DLGDIAG with a complete test, it checks actually every sectors. On my good disks it takes about 5h,
on the suspected bad, well, it never finished, estimated complete time was raising all the time, >100h
when I stopped it. The test program had actually difficulties reading the disk. The sector counters was going
slowly and stopping some time to time. So my disk is definitly broken, I will do a RMA.

However even with some good disk my raid building is very slow (4 x 3TB), I am only at 25% after a day.
Do not know if this normal ?

[raulfg3]

However even with some good disk my raid building is very slow (4 x 3TB), I am only at 25% after a day.
Do not know if this normal ?

yes.

raid5 is declared obsolete by N4F developers and maintain only for compatibility.

use ZFS instead RaidZ1=Raid5 .

ZFS have a lot of features one is that is really fast to create a pool an to resilver in case of a bad disk.

If you do not use advanced features like dedupe, only 2 to 4 GB is enought for home use ( 8GB prefeed for SOHO use).

more info : viewtopic.php?f=65&t=5959&p=32654

[jim71]

yep, but I am using encryption and iscsi.

As far as I have seen encryption is not supported with ZFS and I also read somewhere that for iscsi this is not the best
choice, UFS is better (something to do with fragementation I think, I did not get it).

[raulfg3]

viewtopic.php?f=67&t=4543&p=31229