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  • Slow HDD diagnostics

    From nelsonse48@gmail.com@3:770/3 to All on Wed Mar 17 10:40:29 2021
    I have 4 external drives connected to my rpi4b (4G). 1 is a WD Blue SSD connected to usb3 port with the rootfs. The other 3 are HDDs connected through an USB3 hub to the other rpi usb3 port. One of the HDDs is much slower than the other drives. What
    are some diagnostice commands I could use to try to diagnose why the drive is slower than the others?

    Here are results of lsusb and hdparm outputs with my comments in { }.

    pi@rpi4b:~ $ lsusb
    Bus 002 Device 003: ID 059f:1065 LaCie, Ltd
    Bus 002 Device 004: ID 0bc2:ab28 Seagate RSS LLC
    Bus 002 Device 005: ID 152d:1561 JMicron Technology Corp. / JMicron USA Technology Corp. JMS561U two ports SATA 6Gb/s bridge
    Bus 002 Device 002: ID 2109:0815 VIA Labs, Inc.
    Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
    Bus 001 Device 008: ID 05ac:921d Apple, Inc.
    Bus 001 Device 005: ID 05ac:911d Apple, Inc.
    Bus 001 Device 010: ID 05ac:020b Apple, Inc. Pro Keyboard [Mitsumi, A1048/US layout]
    Bus 001 Device 007: ID 03f0:134a HP, Inc Optical Mouse
    Bus 001 Device 004: ID 05ac:1003 Apple, Inc. Hub in Pro Keyboard [Mitsumi, A1048]
    Bus 001 Device 006: ID 0080:a001
    Bus 001 Device 003: ID 2109:2815 VIA Labs, Inc.
    Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sda
    /dev/sda: {4TB 2.5 HDD unknown rpm}
    SG_IO: bad/missing sense data, sb[]: 70 00 05 00 00 00 00 0a 00 00 00 00 24 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    Timing buffered disk reads: 342 MB in 3.00 seconds = 114.00 MB/sec

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc
    /dev/sdc: {8TB 3.5 HDD 5400rpm}
    Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdd
    /dev/sdd: {3TB 3.5 HDD 7200rpm}
    Timing buffered disk reads: 388 MB in 3.05 seconds = 127.37 MB/sec

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdb
    /dev/sdb: {WD Blue SSD 2.5 form factor, rootfs}
    Timing buffered disk reads: 576 MB in 3.00 seconds = 191.87 MB/sec

    Why is /dev/sdc so slow runnning through same usb3 hub as /dev/sda and /dev/sdd? I don't think it is rotation speed of drives.

    TIA/
    --Steven

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Dennis Lee Bieber@3:770/3 to All on Wed Mar 17 14:47:22 2021
    On Wed, 17 Mar 2021 10:40:29 -0700 (PDT), "nelso...@gmail.com" <nelsonse48@gmail.com> declaimed the following:

    Why is /dev/sdc so slow runnning through same usb3 hub as /dev/sda and /dev/sdd? I don't think it is rotation speed of drives.

    I'd blame rotation speed with a fragmented file system -- fragmentation and head seeks means waiting for the platter to rotate the next desired
    sector into position.

    It's also a larger drive, and if inodes are stored in one area, with data stored elsewhere, and the journal somewhere else, there could be a lot more seeking being performed.


    --
    Wulfraed Dennis Lee Bieber AF6VN
    wlfraed@ix.netcom.com http://wlfraed.microdiversity.freeddns.org/

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Jim Jackson@3:770/3 to nelso...@gmail.com on Wed Mar 17 22:15:15 2021
    On 2021-03-17, nelso...@gmail.com <nelsonse48@gmail.com> wrote:

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc
    /dev/sdc: {8TB 3.5 HDD 5400rpm}
    Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec


    That speed looks like it is running at USB2 speeds. Are you sure the USB adpapter is USB3? Maybe it's USB2

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From nelsonse48@gmail.com@3:770/3 to Jim Jackson on Wed Mar 17 19:19:20 2021
    On Wednesday, March 17, 2021 at 5:15:16 PM UTC-5, Jim Jackson wrote:
    On 2021-03-17, nelso...@gmail.com <nelso...@gmail.com> wrote:

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc
    /dev/sdc: {8TB 3.5 HDD 5400rpm}
    Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec

    That speed looks like it is running at USB2 speeds. Are you sure the USB adpapter is USB3? Maybe it's USB2

    Orico SATA3.0 - 6Gbps enclosure {USB3.0+SATA III; Support capacity 16TB; Support UASP}
    Seagate Barracuda 8TB HDD

    It should be as fast as the other drives.

    --Steven

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Nikolaj Lazic@3:770/3 to All on Thu Mar 18 09:30:27 2021
    Dana Wed, 17 Mar 2021 19:19:20 -0700 (PDT), nelso...@gmail.com <nelsonse48@gmail.com> napis'o:
    On Wednesday, March 17, 2021 at 5:15:16 PM UTC-5, Jim Jackson wrote:
    On 2021-03-17, nelso...@gmail.com <nelso...@gmail.com> wrote:

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc
    /dev/sdc: {8TB 3.5 HDD 5400rpm}
    Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec

    That speed looks like it is running at USB2 speeds. Are you sure the USB
    adpapter is USB3? Maybe it's USB2

    Orico SATA3.0 - 6Gbps enclosure {USB3.0+SATA III; Support capacity 16TB; Support UASP}
    Seagate Barracuda 8TB HDD

    It should be as fast as the other drives.

    Try testing it without other drives connected to that USB hub.

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Richard Kettlewell@3:770/3 to nelso...@gmail.com on Thu Mar 18 10:58:20 2021
    "nelso...@gmail.com" <nelsonse48@gmail.com> writes:
    On Wednesday, March 17, 2021 at 5:15:16 PM UTC-5, Jim Jackson wrote:
    On 2021-03-17, nelso...@gmail.com <nelso...@gmail.com> wrote:

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc
    /dev/sdc: {8TB 3.5 HDD 5400rpm}
    Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec

    That speed looks like it is running at USB2 speeds. Are you sure the USB
    adpapter is USB3? Maybe it's USB2

    Orico SATA3.0 - 6Gbps enclosure {USB3.0+SATA III; Support capacity 16TB; Support UASP}
    Seagate Barracuda 8TB HDD

    It should be as fast as the other drives.

    It _should_ be. But it can happen that a fully USB3 configuration can
    still negotiate only USB2. One of my backup drives used to suffer from
    this. Have a look at what appears in the kernel log when you connect the
    drive (I’m afraid I don’t remember exactly what to look for).

    --
    https://www.greenend.org.uk/rjk/

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Richard Kettlewell@3:770/3 to Dennis Lee Bieber on Thu Mar 18 10:56:06 2021
    Dennis Lee Bieber <wlfraed@ix.netcom.com> writes:
    "nelso...@gmail.com" <nelsonse48@gmail.com> declaimed the following:
    Why is /dev/sdc so slow runnning through same usb3 hub as /dev/sda
    and /dev/sdd? I don't think it is rotation speed of drives.

    I'd blame rotation speed with a fragmented file system -- fragmentation and head seeks means waiting for the platter to rotate the next desired sector into position.

    It's also a larger drive, and if inodes are stored in one area, with data stored elsewhere, and the journal somewhere else, there could be a lot more seeking being performed.

    Filesystem layout isn’t relevant here. ‘hdparm -t’ doesn’t measure filesystem performance, only raw read.

    --
    https://www.greenend.org.uk/rjk/

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Jim Jackson@3:770/3 to nelso...@gmail.com on Thu Mar 18 17:15:54 2021
    On 2021-03-18, nelso...@gmail.com <nelsonse48@gmail.com> wrote:
    On Wednesday, March 17, 2021 at 5:15:16 PM UTC-5, Jim Jackson wrote:
    On 2021-03-17, nelso...@gmail.com <nelso...@gmail.com> wrote:

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc
    /dev/sdc: {8TB 3.5 HDD 5400rpm}
    Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec

    That speed looks like it is running at USB2 speeds. Are you sure the USB
    adpapter is USB3? Maybe it's USB2

    Orico SATA3.0 - 6Gbps enclosure {USB3.0+SATA III; Support capacity 16TB; Support UASP}
    Seagate Barracuda 8TB HDD

    It should be as fast as the other drives.


    There are lots of issues with RPI4 and USB3 attached drives - check the
    forum, especially this _long_ sticky thread ...

    https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=245931

    Always make sure your USB3 A plug is _fully_ pushed into the USB3 A
    socket - otherwise only the USB2 contacts will engage. The USB3 extra
    contacts are further back and might not engage.

    I have a USB3 attached SSD, and then a powered USB3 hub with 2 disks
    attached and get reasonable individual speeds on the disks, i.e. more
    than USB2 speeds. My WD passport 1TB 5400 rpm disks are not super-fast (92MB/sec) but that's to be expected.

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Martin Gregorie@3:770/3 to Richard Kettlewell on Thu Mar 18 17:27:00 2021
    On Thu, 18 Mar 2021 10:58:20 +0000, Richard Kettlewell wrote:

    "nelso...@gmail.com" <nelsonse48@gmail.com> writes:
    On Wednesday, March 17, 2021 at 5:15:16 PM UTC-5, Jim Jackson wrote:
    On 2021-03-17, nelso...@gmail.com <nelso...@gmail.com> wrote:

    pi@rpi4b:~ $ sync; sync; sudo hdparm -t /dev/sdc /dev/sdc: {8TB 3.5
    HDD 5400rpm}
    Timing buffered disk reads: 100 MB in 3.01 seconds = 33.25 MB/sec

    That speed looks like it is running at USB2 speeds. Are you sure the
    USB adpapter is USB3? Maybe it's USB2

    Orico SATA3.0 - 6Gbps enclosure {USB3.0+SATA III; Support capacity
    16TB; Support UASP}
    Seagate Barracuda 8TB HDD

    It should be as fast as the other drives.

    It _should_ be. But it can happen that a fully USB3 configuration can
    still negotiate only USB2. One of my backup drives used to suffer from
    this. Have a look at what appears in the kernel log when you connect the drive (I’m afraid I don’t remember exactly what to look for).

    The easy way to do that it the open a console and run:

    sudo tail -f /var/log/messages

    and then connect the drive. You'll get severa;l log lines that give
    details about the device that you just plugged in, and what USB type
    (USB2, USB3) its connecting as.

    Kill 'tail' by typing Ctrl/C when you've finished.



    --
    Martin | martin at
    Gregorie | gregorie dot org

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)