I have a simple 2TB mirror using a WD Red 2TB and a Seagate NAS 2TB. When copying files to ZFS I observe the following behavior:
Does anyone else have 1+ of the Seagate NAS drives to confirm/deny the same behavior on their system? Is this sort of behavior "expected" with some drives? Any other suggestions or things to try?
Drives:
Smart (
- decent overall throughput: 33 MB/s with
sftp, 65 MB/s with Samba - writes of 80,000 kBps
- periodic stalls in throughput to 0
- one drive's writes drop to zero and one drive to 10,000 kBps
- during the stall ms/w jumps 10x and busy goes to 100+%
- this continues for ~7 seconds and then the copy recovers
- if I detach the WD from the pool, the stall still occurs
- if I detach the ST from the pool, the stall does not occur
- if I swap the order of the drives, the stall still occurs
- if ZIL is disabled (
zfs set sync=disabled), the stalls do not occur
Does anyone else have 1+ of the Seagate NAS drives to confirm/deny the same behavior on their system? Is this sort of behavior "expected" with some drives? Any other suggestions or things to try?
Drives:
Code:
atapci1: <nVidia nForce CK804 SATA300 controller> port 0x9e0-0x9e7,0xbe0-0xbe3,0x960-0x967,0xb60-0xb63,0xd400-0xd40f mem 0xd4001000-0xd4001fff irq 20 at device 8.0 on pci0
ata2: <ATA channel> at channel 0 on atapci1
ata3: <ATA channel> at channel 1 on atapci1
ada1 at ata2 bus 0 scbus2 target 0 lun 0
ada1: <ST2000VN000-1H3164 SC42> ATA-9 SATA 3.x device
ada1: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)
ada1: 1907729MB (3907029168 512 byte sectors: 16H 63S/T 16383C)
ada1: Previously was known as ad4
ada2 at ata3 bus 0 scbus3 target 0 lun 0
ada2: <WDC WD20EFRX-68AX9N0 80.00A80> ATA-9 SATA 3.x device
ada2: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)
ada2: 1907729MB (3907029168 512 byte sectors: 16H 63S/T 16383C)
ada2: quirks=0x1<4K>
ada2: Previously was known as ad6Smart (
smartctl -a /dev/ada1) output:
Code:
smartctl 6.2 2013-07-26 r3841 [FreeBSD 9.2-RELEASE amd64] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Device Model: ST2000VN000-1H3164
Serial Number: W1H2741N
LU WWN Device Id: 5 000c50 06a67ff84
Firmware Version: SC42
User Capacity: 2,000,398,934,016 bytes [2.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5900 rpm
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: ACS-2, ACS-3 T13/2161-D revision 3b
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Wed Nov 6 13:13:07 2013 PST
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: ( 107) seconds.
Offline data collection
capabilities: (0x73) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
No 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: ( 271) 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 119 100 006 Pre-fail Always - 220772792
3 Spin_Up_Time 0x0003 095 095 000 Pre-fail Always - 0
4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 12
5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 063 060 030 Pre-fail Always - 2459484
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 635
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 12
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 007 007 000 Old_age Always - 93
190 Airflow_Temperature_Cel 0x0022 071 060 045 Old_age Always - 29 (Min/Max 28/37)
191 G-Sense_Error_Rate 0x0032 100 100 000 Old_age Always - 0
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 10
193 Load_Cycle_Count 0x0032 100 100 000 Old_age Always - 12
194 Temperature_Celsius 0x0022 029 040 000 Old_age Always - 29 (0 19 0 0 0)
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% 97 -
# 2 Short offline Completed without error 00% 73 -
# 3 Short offline Completed without error 00% 49 -
# 4 Extended offline Completed without error 00% 30 -
# 5 Short offline Completed without error 00% 25 -
# 6 Extended offline Completed without error 00% 4 -
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.