I am using mdadm, samba and RPi4 to create a local nas for my house. It seems to work fine but when I transfer a file from the nas to my local machine, it doesn't use the full 1gbps and only uses 500mbps. Interestingly enough though it does seem to use the full 1gbps if I have recently tried to copy the file, but only for a small portion of the file(see below). Initial Slow Transfer Initial Slow Transfer

Quick speed after initial transfer Quick speed after initial transfer

Then transfers go slow Then transfers go slow

I have also ran iperf3 to test network speeds and these seem to average out at around 913mbps over 30s as can be seen below: iperf3

My madam details are:

pi@RASPINAS:~ $ sudo mdadm -D /dev/md127
       Version : 1.2
 Creation Time : Tue Jun 15 19:19:32 2021
    Raid Level : raid1
    Array Size : 3906886400 (3725.90 GiB 4000.65 GB)
 Used Dev Size : 3906886400 (3725.90 GiB 4000.65 GB)
  Raid Devices : 2
 Total Devices : 2
   Persistence : Superblock is persistent

 Intent Bitmap : Internal

   Update Time : Wed Jun 16 16:46:58 2021
         State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
 Spare Devices : 0

Consistency Policy : bitmap

          Name : RASPINAS:vol1  (local to host RASPINAS)
          UUID : 8a3cf990:89778fe5:e453f818:80f3be22
        Events : 61190

Number   Major   Minor   RaidDevice State
   0       8        1        0      active sync   /dev/sda1
   1       8       17        1      active sync   /dev/sdb1

My samba share config is:

path = /mnt
writable = yes
guest ok = yes
public = yes
read only = no
create mask = 0777
directory mask = 0777

Thanks in advance! :)


are you talking about transferring huge files, small files or you did not notice which ones? NFS itself is much more capable with small files - the issue could be not network but server handling files how about the device between your server and client? any router? wifi or lan? any sharing of the LAN between other devices?

  • Quite big files, about 25gb. There are were no other devices on the network at the time, it was wired with ethernet. Nothing else was using the server at the time.
    – user488476
    Jun 18 '21 at 13:17
  • I have 2 RPi connected via Gbit small switch - I am not getting above 620Mbps in peak. Average it is even less. I just copied 3 files, 1.5GB each (4.5GB in total) and it took 1 minute and 50 seconds so 330Mpbs Jun 18 '21 at 14:12

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