Parity Check speed and write speed slow (max 30MB/s)

[paffeke]

Hi support,

i just installed my unRAID on HPE MicroServer Gen8.
I have 3x2TB drives, 1 for parity and others for volume space.
Parity check is really slow and write speed on disks (over smb and ftp as well) are slow too.

I tried to pause parity and start to upload files and the max speed was 30-34 MB/s.

Just moved from Xpenology to unRAID and i'm still using my trial version, i would like to get unRAID license but with these write performance i really can do it.

 

Some advices?

Thank you so much

nas-diagnostics-20220209-1315.zip

[JorgeB]

Parity disk is SMR, it's going to be slow writing, suggest replacing with a CMR model.

[JorgeB]

Also note that array performance will be degraded while the parity sync doesn't finish, even if you pause it.

[paffeke]

1 hour ago, JorgeB said:

Also note that array performance will be degraded while the parity sync doesn't finish, even if you pause it.

 Perfect i will check again whe  parity will be done.

 

1 hour ago, JorgeB said:

Parity disk is SMR, it's going to be slow writing, suggest replacing with a CMR model.

 I have 1 WD20EFAX (SMR) and 2 WD20EFRX (CMR). In this case you suggest to pick one of WD20EFRX and select as parity disk?

 

After that, is there something else can i do trying to improve writing performance?

Edited February 9, 2022 by paffeke

[JorgeB]

With SMR as parity all writes to the array will be slower, with SMR as a data disk only writes to that disk will be slower, not ideal, but better.

[JorgeB]

Also check this for better write speed, once the parity sync is done and there's no SMR parity:

 

[paffeke]

1 hour ago, JorgeB said:

With SMR as parity all writes to the array will be slower, with SMR as a data disk only writes to that disk will be slower, not ideal, but better.

 

I started with a new config leaving out the disk with SMR and added CMR disks as parity and data. Nothing seems to be changed.

 

1 hour ago, JorgeB said:

Also check this for better write speed, once the parity sync is done and there's no SMR parity:

 

 I already made this configuration with "md_write_method -> reconstruct write". Same speed.

 

Are my disks not really good for unRAID? I remember that with other OS write/read speed were more efficient. I really want to stay wit unRAID and get the basic version after trial.

nas-diagnostics-20220209-1641.zip

[JonathanM]

7 minutes ago, paffeke said:

Nothing seems to be changed.

Wait until parity is synced.

[paffeke]

5 minutes ago, JonathanM said:

Wait until parity is synced.

Ok i will wait and give a feedback tomorrow. Now parity needs almost 15h to complete.

Thank you for your support

[JorgeB]

Not sure about gen8, but gen7 came with write cache disable in the BIOS, this will also seriously hurt write performance, check yours.

[paffeke]

26 minutes ago, JorgeB said:

Not sure about gen8, but gen7 came with write cache disable in the BIOS, this will also seriously hurt write performance, check yours.

 Enabling write cache and AHCI on BIOS settings did the trick!
Sorry, i didn't think that was disabled, i saw these performance only with unRAID.

 

Thank you so much for your support!

[Jobine]

Hi,

I found the AHCI parameter, but not the one for Enabling write cache.

 

I have a Asus Strix Z270E.

 

Thank,

[JorgeB]

10 minutes ago, Jobine said:

but not the one for Enabling write cache.

That was for a HP Microserver that usually come with write cache disable, regular desktop boards usually don't have that setting.