Hi

We have a gen8 HP Microserver with quad core Xeon CPU and 6gb of ecc ram  with a 3 HDD array and parity drive with UNRAID O/S obviously, all working fine but when we send files such as movies or copy files the write speed starts at 112mb/s for about 30 seconds then it drops to 10mb/s for the rest making the copying of files painfully slow, can anybody advise on how to improve this please?

Many thanks

K

Check if write cache is enable in the bios, it defaults to disable.

Hi

Thanks for reply, it is disabled, should it be enabled?

Thanks

K

Hi thanks for short reply,

checked it in bios - its disabled

I absolutly don´t understand how it could work perfect on 112 MB starting with and then dropping to unacceptable 10 MB/sec.

Because the first few GBs are cached to RAM.

21 minutes ago, keymaster said:

Thanks for reply, it is disabled, should it be enabled?

 

Yes.

hi, no changes at all as i expected. and option is dangerous if you losing power - all data go to nirwana.

 

its still copying with 10 mb/s - no improvement.

Hi

Thank you for very much for your response, unfortunatly this made no difference. My German friend above (Doppelt) is very unhappy about this and saying it makes UNRAID unusable for him and unhappy about my recommendation for him to change his system over to it. :-(

thanks

K

Have you enabled turbo write (reconstruct write)?

What speed is your ethernet adapter connected at?

 

nic is about 1gb and what is turbo write and were can i find that option ?

35 minutes ago, doppelt said:

and option is dangerous if you losing power - all data go to nirwana.

 

Only if you don't have an UPS, and you should have one.

 

35 minutes ago, doppelt said:

its still copying with 10 mb/s - no improvement.

 

Try turbo write or post your diagnostics after a copy.

 

 

Edited September 23, 20178 yr by johnnie.black

thanks - very good.

 

I did modification without a restart. Is one necessary ?

 

this at least improved performance from 10 to about 23-26 MB/s.

 

I´m not that familar with Linux systems.
What I absolutly don´t get is that reduce in speed after that 30 secs.
Is it depending on the parity disk ?

 

I had a xpnology running on the machine before and would like to change OS because of weak support of the cpu by 2 Cores.

Ok, it was a JBOD System without any array and parity drive.

But never would have thought about that difference in speed !

 

And sorry, english is not my mother language and every explanation has to be read twice. There also could be a few misspellings - please be patient.

 

btw: nice forum and i feel home after that only 5 postings

13 minutes ago, doppelt said:

What I absolutly don´t get is that reduce in speed after that 30 secs.

The first part of the transfer is cached in RAM, you are not writing to the actual disks that fast.

Post your diagnostics, maybe something will be visible there, with modern disks you should get around 50MB/s with turbo write disable and line speed with it enable and gigabit.

 

Tools -> Diagnostics

ok thats clear with cache and ram.

 

but we are talking about sata 3 wd black - its a laugh for that hdds to write that speed !

 

may be i didn´t got it clear to understand the leak in writing speed.

thanks to all helping me.

 

next problem was to download the zip file in diagnostics.

 

firefox blocking it - but MS edge is working.

 

what info of the log file you need ?

 

i will post instandly.

 

thanks in advance

Post the complete zip

here it is.

tower-diagnostics-20170923-1505.zip

Nothing obvious, disk2 is showing a couple of pending sectors, possibly false positives and don't appear related to your problem.

 

1 hour ago, doppelt said:

but we are talking about sata 3 wd black - its a laugh for that hdds to write that speed !

 

Your parity disk is an older WD green, and that will be slower than the others, unRAID can't write faster to the data disks then it can write to the parity disk, still I would expect better speeds than you're getting, as long as all disks are healthy.

 

If write cache is already enable in the bios maybe run diskspeed to check if all disks performance is normal, or try temporailly disabling parity and write to a couple of disks to confirm if there's no other issues.

5 minutes ago, johnnie.black said:

disk2 is showing a couple of pending sectors, possibly false positives

 

Forgot to say, you want to make sure those pending sectors are a problem or not by running an extended SMART test on that disk.

checked all with deactivated parity, - write speed about 25 MB/sec.

 

could not be a problem of the wd green.

 

would it be better with more ram ?

Edited September 23, 20178 yr by doppelt

1 minute ago, doppelt said:

could not be a problem of the wd green.

 

It also proves it's not an unRAID problem, as without parity data disks behave just as a single disk in Linux , double check write cache is enable, can't think of another logical reason, or there's another hardware issue somewhere.

Make sure that the sending PC has the latest drivers for the NIC chip set.  I had issues with transfer speeds that I traced to outdated RealTek NIC drivers on my Win7 computers!

 

EDIT:  If that is not the issue, Reboot all switches and Routers on the network.  (All of those contain little computers and a occasional reboot will sometimes 'fix' problems by re-initializing everything.)

Edited September 23, 20178 yr by Frank1940