Why is my storage getting slower and slower?

[wywywywy]

Hi all,

Basically I built a FreeNAS box on a HP MicroServer G7 about a year ago, with four HGST 4TB drives using ZFS.

At the time, the transfer rate was about 60-70 MB/s. Not lightning fast but enough for home use.

However, it's been getting slower and slower every month. Last night I got about 11 MB/s transferring a 1GB video file.

I have no clue what's happening. Any ideas what I can check please?

It's on 9.3 with 16GB of ECC memory and about 3TB free space.

Thanks.

 

[SweetAndLow]

As you fill your pool it becomes fragmented and speed decreases. Speed really starts to show down when your pool for past 80% full, that is why it's suggested to keep it under 80%. You might also have a HDD failure, do you run smart tests?

 

[wywywywy]

Hi,

Long SMART test scheduled once a week, short SMART test once every six hours.

I've never received emailed from the server about SMART problems.

Thanks.

 

[wywywywy]

Looking is smartctl -a, it says "No Errors Logged", and all of the "Short offline" entries say "Completed without error" on all four drives.

When I do the dd test in the sticky post, I get about 700 MB/s write and 1000 MB/s read!! (Am I even doing it right?)

dd if=/dev/zero of=tmp.dat bs=2048k count=50k
51200+0 records in
51200+0 records out
107374182400 bytes transferred in 154.122923 secs (696678860 bytes/sec)

dd of=/dev/null if=tmp.dat bs=2048k count=50k
51200+0 records in
51200+0 records out
107374182400 bytes transferred in 98.688473 secs (1088011387 bytes/sec)

 

[wywywywy]

So it looks like a CIFS problem rather than a storage problem.

I'll go and ask over there instead.

Sorry for bothering.

 

[SweetAndLow]

Do you have compression enabled? That will skew your results.

 

[Tywin]

Do you have compression enabled? That will skew your results.

As it turns out, zeroes compress pretty well ;)