Exremely slow file transfer speed from USB 3

[Corrupt_Liberty]

This is my first time using Unraid.  I am currently running version 6.9.2 on an HP ML350 G6.  I have 2x Xeon X5675 CPUs and 72 GB ECC RAM.  I have setup an array with 8 2TB SATA disks 2 of which are parity drives connected with an LSI 9207-8i in IT mode.  I installed the plugin for Unassigned Devices and am using the Krusader Docker for initial file transfer.  I have the PLEX Docker installed also but it is not currently running.

 

Now that I have the specs out of the way, I am attempting to transfer my media backup from an 8TB USB 3 HDD to my Unraid Array.  I am now getting speeds of 3-5 MiB/s with an expected completion of 6 days for a 2.9 TiB transfer.  Am I doing something wrong?  I see other posts complaining about 40 MiB/s.  I would be thrilled to hit that mark. 

 

Any assistance would be appreciated.  Thanks.

[trurl]

Attach Diagnostics to next post 

[Corrupt_Liberty]

Apologies, I'm very new to this.  Diagnostics attached.

kris-server-diagnostics-20210915-0633.zip

[trurl]

I noticed you were rebuilding disk1. Were you trying to transfer files to your server at the same time?

[Corrupt_Liberty]

No, disk one had a lot of reallocation errors the first time I attempted to copy files over.  I stopped the transfer and replaced the drive thinking it might be causing some issues.  It was several years old.  Rebuilding the drive only took 12 hours and that was completed before trying to transfer more files to the array. 

[Corrupt_Liberty]

I saw someone mention on another forum that HP RAID cards disabled the internal cache of HDDs connected to them.  Is this possibly correct?  I know the raid card had its own cache.  Would this cause horribly slow writes?  If so, how would one go about re- enabling the internal cache on the drives? 

[JonathanM]

What kind of speeds do you get if you connect the external drive to your local machine and send the files over the network?

[Corrupt_Liberty]

1 hour ago, JonathanM said:

What kind of speeds do you get if you connect the external drive to your local machine and send the files over the network?

Maybe slightly faster?  Seems pretty much the same to me.  But copying to my desktop I get about 130 MiB/s from the USB drive.

[JonathanM]

See what kind of speeds you get with this.

 

[Corrupt_Liberty]

1 hour ago, JonathanM said:

See what kind of speeds you get with this.

 

 

Everything seems normal with one obvious outlier that is oddly fast.  Not sure what this means.

 

[Corrupt_Liberty]

So I started up a large transfer again.  The speed starts out great at about 130 MiB/s.  After about 2 minutes it's down to 30 MiB/s.  At the 5 minute mark it's down to 20 and just keeps sliding downward.  By 10 minutes it's at 4-5 MiB/s and just stays there.

[JorgeB]

You're using SMR drives, and the WD20SPZX particularly is know to be a bad performer. 

[Corrupt_Liberty]

1 hour ago, JorgeB said:

You're using SMR drives, and the WD20SPZX particularly is know to be a bad performer. 

I understand I won't be getting the best performance from the WD drives.  I'm even okay with half the speed.  Before switching to unraid I had these exact drives in a traditional RAID 5 connected to the onboard P410i and was getting 40-60 MiB/s. Not to mention at present it is writing to a Seagate drive which is perpendicular recording.  I'm not expecting blazing fast speeds. Just better than 4 MiB/s.

 

Once I'm finished dumping all my existing media on the array I'll be adding a TiB of SSD cache and will hopefully never be moving this much data to the array again so SMR should be a non-issue.  I just didn't want to hit the SSDs when I have 8TiB of media to get everything started.  At this rate my trial license will run out before I get a chance to actually test my PLEX setup with all my data. 

[JorgeB]

Unraid is not RAID, it doesn't stripe writes, it writes to only one disk at a time, and with SMR disks writes speeds of 5MB/s are normal, I have some myself.

[Corrupt_Liberty]

13 minutes ago, JorgeB said:

Unraid is not RAID, it doesn't stripe writes, it writes to only one disk at a time, and with SMR disks writes speeds of 5MB/s are normal, I have some myself.

Then wouldn't my performance improve when writing to the Seagate drives?  It seems to actually be faster when it was on the WD.  Now that it hit 1TB it has moved onto a Seagate disk and seems even slower, albeit not much slower.  Is this just a normal function of calculating parity?

 

Also, I'm assuming that read speeds won't be this problematic.  What is the best way to test this before dropping $90 on Unraid?  I've already spent a week trying to set this up, I'd hate to waste the money too only to realize I'll be better off going back to Lubuntu with the old RAID card.

[JorgeB]

Also note that on the diskspeed graph all the  WD SMR drives are not performing normally during reads, SMR doesn't affect reads, and they should perform similarly to the Seagates, but are much slower, which is common on those models after some time, disk6 is likely mostly factory clear, or it was wiped, speed is much higher because it's not reading the actual disk surface, it's also normal on those disks.

[JorgeB]

1 minute ago, Corrupt_Liberty said:

Then wouldn't my performance improve when writing to the Seagate drives?

Seagates ae also SMR, and even if they are likely to perform a little better than the WDs, they are still limited by the WD parity disks.

[Corrupt_Liberty]

3 minutes ago, JorgeB said:

Seagates ae also SMR, and even if they are likely to perform a little better than the WDs, they are still limited by the WD parity disks.

Seagate lists that model as perpendicular.  Not that means they are any good.  I was trying out the WD drives after my third failed Seagate.

[Corrupt_Liberty]

6 minutes ago, JorgeB said:

Also note that on the diskspeed graph all the  WD SMR drives are not performing normally during reads, SMR doesn't affect reads, and they should perform similarly to the Seagates, but are much slower, which is common on those models after some time, disk6 is likely mostly factory clear, or it was wiped, speed is much higher because it's not reading the actual disk surface, it's also normal on those disks.

Yes, Disk 6 is brand new.  Less than 200 hours on it now and almost no writes.

[Corrupt_Liberty]

 

I just found this post/guide from last year.  My transfer has just gone from 4 MiB/s to over 100.  Now hopefully I can transfer all of my files and then have a 12 hour parity sync at the end.

Someone needs to make this a sticky!!

[Skatman]

On 9/17/2021 at 11:22 AM, Corrupt_Liberty said:

 

I just found this post/guide from last year.  My transfer has just gone from 4 MiB/s to over 100.  Now hopefully I can transfer all of my files and then have a 12 hour parity sync at the end.

Someone needs to make this a sticky!!

It's always a lovely feeling when something you write with the objective of helping people in a similar position to you, helps someone in a similar position to you.

 

Glad it helped! This was a pain in the backside for me too, except I had 20TB of data to move haha.

[Corrupt_Liberty]

33 minutes ago, Skatman said:

It's always a lovely feeling when something you write with the objective of helping people in a similar position to you, helps someone in a similar position to you.

 

Glad it helped! This was a pain in the backside for me too, except I had 20TB of data to move haha.

I was on the verge of abandoning Unraid altogether before I found your post.  You definitely saved me days of work.  My server has been humming along nicely ever since.