I have some strange results from some burn in tests of 4x WD Red 1Tb drives using this test script ( https://forums.freenas.org/index.php?resources/solnet-array-test.1/ ).
The box is an HP Proliant N40L 16Gb ECC RAM running Freenas 9.10. http://m.hp.com/h20195/v2/GetPDF.aspx/c04111079.pdf
There was nothing scary in the SMART tests or badblocks so I moved on to the solnet v2 test script. I have run the same test a few times, becoming increasingly frustrated, before deciding to be more scientific- recording and posting my results. These are the results from the parallel seek stress-test from three runs, moving the disks to different bays (cables) between each test.
Test 1 shows disk C50 on ada0 is the slowest and Y75 on ada2 is next. Fastest is DKA on ada3.
For Test 2 I moved DKA to the slowest bay, C50 to the fastest bay, and swapped the two middle ones. Test 2 shows C50 on ada3 is again the slowest disk by far. It must be a bad disk, right?
Let's do one more before I return it...
Test 3 I reordered the disks again and now C50 is the fastest disk.
This range of results is much wider than I had expected. If it's not the disk, what else might cause one (or two) disks to underperform the others by such a wide margin? Is this to be expected in tests like this?
Thanks for any suggestions.
The box is an HP Proliant N40L 16Gb ECC RAM running Freenas 9.10. http://m.hp.com/h20195/v2/GetPDF.aspx/c04111079.pdf
There was nothing scary in the SMART tests or badblocks so I moved on to the solnet v2 test script. I have run the same test a few times, becoming increasingly frustrated, before deciding to be more scientific- recording and posting my results. These are the results from the parallel seek stress-test from three runs, moving the disks to different bays (cables) between each test.
Test 1 shows disk C50 on ada0 is the slowest and Y75 on ada2 is next. Fastest is DKA on ada3.
For Test 2 I moved DKA to the slowest bay, C50 to the fastest bay, and swapped the two middle ones. Test 2 shows C50 on ada3 is again the slowest disk by far. It must be a bad disk, right?
Let's do one more before I return it...
Test 3 I reordered the disks again and now C50 is the fastest disk.
This range of results is much wider than I had expected. If it's not the disk, what else might cause one (or two) disks to underperform the others by such a wide margin? Is this to be expected in tests like this?
Thanks for any suggestions.
Code:
TEST 1 ====== ada0 WD-WCC4J4CKNC50 ada1 WD-WCC4J5KJAL7Z ada2 WD-WCC4J5KJAY75 ada3 WD-WCC4J5KJADKA Awaiting completion: initial parallel seek-stress array read Fri Jul 1 06:08:08 PDT 2016 Completed: initial parallel seek-stress array read Disk's average time is 29487 seconds per disk Disk Bytes Transferred Seconds %ofAvg ------- ----------------- ------- ------ ada0 1000204886016 39078 133 --SLOW-- ada1 1000204886016 23656 80 ++FAST++ ada2 1000204886016 35930 122 --SLOW-- ada3 1000204886016 19285 65 ++FAST++ TEST 2 ====== [root@freenas] ~# camcontrol identify ada0 | grep 'serial' serial number WD-WCC4J5KJADKA [root@freenas] ~# camcontrol identify ada1 | grep 'serial' serial number WD-WCC4J5KJAY75 [root@freenas] ~# camcontrol identify ada2 | grep 'serial' serial number WD-WCC4J5KJAL7Z [root@freenas] ~# camcontrol identify ada3 | grep 'serial' serial number WD-WCC4J4CKNC50 Awaiting completion: initial parallel seek-stress array read Sat Jul 2 08:35:36 PDT 2016 Completed: initial parallel seek-stress array read Disk's average time is 28306 seconds per disk Disk Bytes Transferred Seconds %ofAvg ------- ----------------- ------- ------ ada0 1000204886016 22063 78 ++FAST++ ada1 1000204886016 19573 69 ++FAST++ ada2 1000204886016 22131 78 ++FAST++ ada3 1000204886016 49458 175 --SLOW-- TEST 3 ====== [root@freenas] ~# camcontrol identify ada0 | grep 'serial' serial number WD-WCC4J5KJAL7Z [root@freenas] ~# camcontrol identify ada1 | grep 'serial' serial number WD-WCC4J4CKNC50 [root@freenas] ~# camcontrol identify ada2 | grep 'serial' serial number WD-WCC4J5KJADKA [root@freenas] ~# camcontrol identify ada3 | grep 'serial' serial number WD-WCC4J5KJAY75 Awaiting completion: initial parallel seek-stress array read Tue Jul 5 06:10:24 PDT 2016 Completed: initial parallel seek-stress array read Disk's average time is 26778 seconds per disk Disk Bytes Transferred Seconds %ofAvg ------- ----------------- ------- ------ ada0 1000204886016 36073 135 --SLOW-- ada1 1000204886016 19194 72 ++FAST++ ada2 1000204886016 30929 116 --SLOW-- ada3 1000204886016 20916 78 ++FAST++