Slow network transfer on gigabit between Win7 and Ubuntu Samba (26 MB/s)

Question

I have slow network transfer speed (26 MB/s). The beginning of the transfer started at 120 MB/s and dropped down every second.

I am transferring a 350 GB file from an E-Sata (7200rpm) drive mounted on Windows 7 to a Ubuntu Samba share (on esxi). The samba share is mapped to a drive letter on Win 7 by IP address.

ethtool eth0 shows:

Settings for eth0:
Supported ports: TP
Supported link modes: 10/100 half/full, 1000/full
Supports auto-negotiation: Yes
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Speed: 1000MB/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Supports Wake-on: d
Wake-on: d
Current Message level: 7
link detected: yes

If you checked the speed of both disks, and checked the raw network speed with `iperf` or similar, then make sure you connect with SMB2 or SMB3, not SMB1 which is slower. And/or show us the output of `testparm -s` and `smbd --version` on your Samba server. — mivk, Oct 14 '20 at 14:50

score 3 · Answer 1 · edited Oct 14 '20 at 11:52

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The hard drive almost certainly only supports ~26MBps. Even the latest round of SATA drives can barely pull double that number (under ideal conditions).

That beginning speed of 120MBps isn't even really possible; 1000Mb / 8 * 80% = ~100MBps (realistic max). Windows caching is playing with the numbers, hence the high initial speed and after a while the number settles to the sustainable throughput.

edited Oct 14 '20 at 11:52

RiGiD5

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answered Apr 27 '11 at 13:14

Chris S

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Modern SATA disks can give linear sustainable speeds up to 100MB/s and more. 200MB/s is not uncommon with disks with large data densities. – Konrad Gajewski Oct 13 '20 at 17:31
Man it was 2011 when the guy was replying. – RiGiD5 Oct 15 '20 at 15:23

score 1 · Accepted Answer · answered Apr 27 '11 at 13:33

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Just try to test disk for wtite speed with dd in linux. and then check your network with iperf. and you ll know where is a bottle neck.

answered Apr 27 '11 at 13:33

MealstroM

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score 0 · Answer 3 · answered Oct 13 '20 at 17:24

For everyone to know: on Ubuntu 20.04.1 and ARM64 (where this does comply with standard x64 system) with Samba I had transfer both directions at about 115 MB/s, which means that with Gigabit Ethernet you can achieve much higher speeds than mentioned in the question - using SSD drives, memory or data produced from /dev/zero.

Problem can be:

Ethernet working on one side (source/target) at 100 Mb/s
Not proper file system (in my case NTFS was not giving more than 30 MB/s)
HDD which for SATA gives max at around 130 MB/s

Slow network transfer on gigabit between Win7 and Ubuntu Samba (26 MB/s)

3 Answers3