02-20-2011 01:40 AM - edited 02-20-2011 01:42 AM
I wished for and got 3 Seagate 7200.12 1TB drives model ST31000528AS for christmas. These was to replace some 7200.10 250GB drives in my server's hardware raid 5 setup.
The problem is that the new raid with the 3 discs is underperforming massively compared to the old one with 250GB discs, i get only ~40Mbyte/sec read and ~20 Mbyte/sec write. (Yes, write back cache is enabled).
I began investigating the problem and whenever i ran a speed test on the raid one disc would have the activity led fully on indicating that it was heavily loaded and the 2 others were visibly less loaded to the point where the activity led would show no activity for 100-200ms ..
The raid being a RAID5 allows for me to pull one disc without crashing the system and i have now tried pulling alle 3 discs in turn(Letting the RAID rebuild inbetween)..
I have then made comparable test runs on another machine with the drives under exact same conditions and found that the drive that was massively loaded is underperforming compared to the 2 others and since raid 5 is only as fast as the slowest drive i guess that this drive is the culprit.
Strangely enough seatools passed the drive on all tests so i dont know how i am going to get this drive replaced..
This is the HDTune tests i have done.
DISC 1 :
DISC 2 :
DISC 3 :
As you can see disc 3 is performing alot worse. To eliminate any posibility of me doing something wrong i tested disc 3, then disc 2, then disc 1 and lastly i tested disc 3 again.
All discs was connected to my desktop computer, the computer was started and as soon as it had finished booting and the activity led indicated that everything was loaded i started up HDTune and ran the test right away. I ran it 3 times in a row for drive 3 the second time i had it in and the all 3 tests were the same and matched the test done at first.
What do i do ? Is it possible to get this clearly underperforming drive replaced when seatools reports no errors ?
PS. The drives was delivered with firmware CC38 but when looking into the problems i have i found that there was a CC46 out and all drives was upgraded to CC46. The HDTune tests are made with the drives at firmware level CC46.
02-22-2011 05:49 AM - edited 02-22-2011 05:51 AM
Just to add to this thread that when running the RAID without disc 3 it performs alot better than with disc 3.
Still wanting to know what to do with the defective one when seatools says PASS on all tests ?
02-22-2011 06:42 AM
Same problem here But with 500Gb ST3500418AS[CC38 FW] , U can see my thread it's underperforming, i'm getting average speed of 20Mb/s sometimes it goes to 50Mb/s it Varies alot, Don't know what's causing it, No S.M.A.R.T errors , I have changed SATA Cable . Changed Ports,
I have ANother 1TB Seagate ST31000528AS [CC38 FW], which is performing good getting Around 60-75Mb/s Constant.....
03-02-2011 08:37 AM
Talked to the company that sold me the 3 disks.
It seemed that they had had a few of these underperforming disks and the only reason i found out was because i was using it in a raid and had 2 totally identical discs to compare with so only gosh knows how many bad disks are out there.
Have been a seagate guy for quite some years(Since the IBM GXP75 drive days) but after the 7200.11 1.5TB drive i bought that needed several firmware upgrades just to work close to satisfactory and now this bad drive i am going to seriously consider changing to another brand.
The company that sold it to me told me to take the 3 speedtests, mark them with the corresponding serials that i bought and send the defective drive back and they would have a look at it. I got the impression that they also were a bit tired of having to deal with all these bad seagate drives compared to the other brands but i think i will get it changed.
03-16-2011 07:17 PM
03-24-2011 09:02 AM
I got the company that sold me the drive to exchance it, they agreed that the drive was faulty and ended up sending the drive to seagate for analysis on their own.
Only cost was the price to send the drive to them ..