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I have built myself a small Ubuntu home server to store all my files, but one of my HDD has extremely low write speed (between 1 and 3 MB/s) and it's killing me because it's a 4TB drive and I have almost 2.5TB of data to put on it. Let me explain :

I bought my server with the following specs :

  • CPU : Intel Pentium G3440
  • MB : Asus H87M-E C2
  • RAM : Corsair 2 x 2GB DDR3

And with the following drives (one partition on each drive) :

  • SSD (sda) : Kingston HyperX 120GB SATA3
  • HDD (sdb) : WD Green 4TB SATA3
  • HDD (sdc) : Seagate ST4000 4TB SATA3
  • HDD (sdd) : WD Green 3TB SATA3

I installed Ubuntu 14.04 (with GNOME) on the SSD, and "salvaged" the Seagate 4TB drive from my Windows 7 x64 computer and it was full of data. It was partitionned in NTFS, and had Compression active (gained a couple of GB with this).

When I moved it to my server, I emptied it into the other drives (took me around 3 weeks, at an average speed of 2MB/s). I thought the low read speed was due to the fact that I was transferring from (compressed) NTFS to Ext4. Now that I have emptied the drive, and reformated it to Ext4 I assumed it would be much better, but when I tried to copy back some of the files, I saw that the average speed was still similar (around 2MB/s). So tried some other copies to test the speeds between the other drives, and all copies I try doing between the 3 large capacity drives (sdb, sdc, sdd) go slower than 2.7MB/s (sometimes as slow as 1MB/s).

Is there something I'm missing here ? Either Ubuntu configuration, partition settings, fstab parameters...

Please comment if you need me to post the result of some command. Here are the few I could think of (will edit if/when I have some new informations) :

/etc/fstab contents

#sdb1
/dev/sdb1 /media/tv         ext4    user,sync,auto,rw   0   0

#sdc1
/dev/sdc1 /media/tvarchive  ext4    user,sync,auto,rw   0   0

#sdd1
/dev/sdd1 /media/medias     ext4    user,sync,auto,rw   0   0

smartctl -H -i /dev/sdc

rgo@ATLAS:~$ sudo smartctl -H -i /dev/sdc
smartctl 6.2 2013-07-26 r3841 [i686-linux-3.13.0-44-generic] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Seagate Desktop HDD.15
Device Model:     ST4000DM000-1F2168
Serial Number:    Z300RC7R
LU WWN Device Id: 5 000c50 0647493a8
Firmware Version: CC52
User Capacity:    4 000 787 030 016 bytes [4,00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5900 rpm
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ATA8-ACS T13/1699-D revision 4
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Sun Jan 25 13:39:15 2015 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

hdparm -Tt

rgo@ATLAS:~$ sudo hdparm -Tt /dev/sdc
[sudo] password for rgo: 

/dev/sdc:
 Timing cached reads:   16144 MB in  2.00 seconds = 8080.82 MB/sec
 Timing buffered disk reads: 446 MB in  3.00 seconds = 148.67 MB/sec

hdparm -v

rgo@ATLAS:~$ sudo hdparm -v /dev/sdc

/dev/sdc:
 multcount     = 16 (on)
 IO_support    =  1 (32-bit)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 486401/255/63, sectors = 7814037168, start = 0
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Excuse me if my question is stupid, but did you connect your HDDs to motherboard via SATA cables, not USB, right?
The next question is why you have 'sync' in /etc/fstab? I dont have one in mine. Please try without this.

  • Holy mother !!! Now we're talking !!! Yes the HDD are internals, and I don't know why the "sync" option. I was looking for a way to auto mount my disks on boot (UNIX beginner), and copied it from somewhere on the Internet. Now that it's removed, I'm reaching 70 MB/s copy speed !!!! Thank you so much !!! – 3rgo Jan 25 '15 at 22:22

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