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i have a problem which i cannot identify correctly. I have a process (on WinSrv 2008 R2) which imports data into Mongo DB and periodically whole system freezes - once per 5-10-15 minutes for about 20-30 seconds. During freezes HDD led on the computer box is constantly 'on' and all processes that somehow access SSD are not responsive. After some time (15-30 seconds) system unfreezes and perfmon shows disk queue length of 800+ (whereas normally it is not more than 5-10).

Screnshot from perfmon is here http://clip2net.com/s/5wVBPP

I suspect there is some hardware problem with SSD, which is Intel 520 120GB (was tried with similar or worse result /system hangs completely/ - in different boxes with latest SSD/BIOS firmwares and drivers). The question is - are there are some other reasons possible?. Is it normal for Intel 520 /my company installs only Intel hardware, so there seems to be no other hardware choice/?

Xtra Coder
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  • It's probably a hardware problem, it may be related to the disk or the controller itself. – Martino Dino Aug 08 '13 at 10:22
  • "My company installs only Intel hardware, so there seems to be no other hardware choice". Intel use a range of controllers in their different models. The 520 uses a Sandforce controller, albeit with a custom Intel firmware. However, it's a different SSD entirely to the 320 series, or to the newer DC3500 or DC3700 series (w/ Intel controllers). This isn't addressing your actual question, of course, but SSD behaviour is far more dependant on controller manufacturer than SSD manufacturer. There are other Intel SSDs you can use. – Daniel Lawson Aug 11 '13 at 02:41

3 Answers3

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Hardware or Software issue, with Software being the firmware on the drive.

The SSD likely decides it needs to do some cleanup / garbage collection RIGHT NOW and stops any answering until that is done. CHeck firmware versions, apply upgrade as feasible, otherwise RMA drive for replacement.

Not sure about Intel - they have a REALLY good reputation - but OCZ did that in older versions at times, though they got that under control finally ;)

TomTom
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  • Any what? I think you accidentally a.. – Tom O'Connor Aug 08 '13 at 11:17
  • Well, and the firmware stops answering until that is done. CHeck firmware versions, apply upgrade as feasible, otherwise RMA drive for replacement. – TomTom Aug 08 '13 at 11:19
  • Do you want to edit that into your answer? – Tom O'Connor Aug 08 '13 at 11:21
  • Personally, i think exactly the same - "*The SSD likely decides it needs to do some cleanup / garbage collection RIGHT NOW and stops any answering until that is done*" - but i could not find any proof/reason of that for Intel 520 when googling. ---- **PS**: I rechecked all firmwares/drivers to be the latest before posting the question here - no help this way :( ---- And Intel SSD Toolbox is also all green. **PPS**: I took personal Vertex 4 SSD from home, was testing with it last few hours in the same computer box - no problems. So - there seems to be the problem with Intel 520 itself ... – Xtra Coder Aug 08 '13 at 13:26
  • Yeah. I would definitely RMA it. – TomTom Aug 08 '13 at 13:30
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How full is the disk?

If the disk is nearly full (80-90%) the disk has to work extra hard doing garbage collection.

I saw this situation recently where the queue depth and transaction time on one particular box were much worse than the rest and that particular disk was at 90%.

chris
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  • The last time, before testing in new computer box, SSD was cleaned - final result is - (DB takes ~34GB) + (other staff ~40GB) + (~44GB free) = ~120GB. Problems appear shortly after start - i.e. at DB size of 1GB and total disk usage around 50% or less. – Xtra Coder Aug 08 '13 at 13:14
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I've got unexpected remedy for that problem - when replugging Intel 520 from old computer box into current one the guy who did it pluged SSD into SATA2 port. When I noticed that the drive was replugged into SATA3 port - all problems went away.

BTW: chipset is Intel Q75 - very strange conflict of Intel with Intel (Vertex was also plugged into SATA2 port and was working slower than possible, but without glitches) ...

Thanks for your help anyway.

Xtra Coder
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