Two USB hdd / flash drives as RAID 0 on E02 ?

Hi

I would like to make disk access on an E02 faster than using a single flash drive / usb hdd by combining two usb hdd or flash drives as a RAID 0 ( I know that I double my chances of data corruption, but redundancy is not that relevant here, I make daily backups and the files do not change that much - Logitech Media server for music - and access speed is more the issue).

I read that it is possible, but is it advisable? What are the speed gains? Problems when using flash drives instead of usb hdd? And as someone who has no experience with RAID: could I do the same with 3 flash drives / usb hdd and get even more speed out of it?

Would it be to much for the poor E02?

Thanks,

Rainer

===========================
Blog: https://rmkrug.wordpress.com/

1 x Pogoplug E02 (pink): Logitech media server

1 x Pogoplug E02 (pink): FTP server only (throw away configuration - quick to rebuild)

1 x GoFlex Net: running OpenMediaVault

I don't have a Pogoplug E02. So, I don't know if it has a SATA port or not. Regardless, if you are trying to do this through USB2 ports, then I don't think you will get any throughput improvements. Rather, you may wanna invest on this inexpensive MINI 5Gbps Super Speed USB 3.0 Micro SD/SDXC TF Card Reader. I tested this on my AMD64 and/or PogoPlug Pro 02 with a 32 GB SD and/or microSD card and was able to attain a R/W throughput of 30/15 MBps. If I use any USB2 card reader, the R/W throughput is about 4/2 MBps on the same hardware.

(E02 dosen't have SATA)

One thing I've established on my E02 is that a USB 3.0 stick has 2-8 times faster ins and outs, but I kick myself for not trying something. And that's to have two USB 3.0 sticks, one for OS and another for payload. I don't have any extra USB 3.0 sticks to try it either, but maybe someone else does. Seems the absolute IO limit is 30-15 and that's great actually.

I've always wondered though and never tested, if one USB port is slowed to say 2Mb does this affect the other USB sticks? When they say Universal serial bus I've made assumptions on our tech highway if a bike is on the highway the cars have to go that slow too.

=========
-= Cloud 9 =-

JoeyPogoPlugE02 Wrote:
I've always wondered though and never tested, if
> one USB port is slowed to say 2Mb does this affect
> the other USB sticks?

have a look at the USB spec.

http://www.usb.org/developers/docs/usb20_docs/ & https://en.wikipedia.org/wiki/USB

Simple answer.... depends on how you use the devices. Does a USB keyboard slow your usb stick down when you add your usb scanner and keep typing? No, however, they do still share the same bus.

Ponder this: When you add a slow hdd to a fast hdd, does it slow the system down? depends on how you configure and use it, if you raid a slow to a fast, you get a slow(er) than optimal setup. if you separate a slow and a fast, you get most of the features and pitfalls of slow and fast.

It all depends on your attached devices capabilites and timeslicing across the usb bus which is then determined by its maximum data rate.

USB3 on the other hand, is a different kettle of fish...



Edited 2 time(s). Last edit at 03/31/2016 08:12AM by Gravelrash.

Posting some wisdom from wikipedia:

RAID 0 (also known as a stripe set or striped volume) splits ("stripes") data evenly across two or more disks, without parity information, redundancy, or fault tolerance.

A RAID 0 array of n drives provides data read and write transfer rates up to n times higher than the individual drive rates

https://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_0

This is true on any device, as long as the bus they are using to communicate with the CPU isn't shared, see below.


> I've always wondered though and never tested, if one USB port is slowed to say 2Mb does this affect the other USB sticks?


As with all bus and interfaces, you need to look how the controllers are arranged.

If each port has its own controller, the speed of one port is not affected by devices on others.

If there is one controller and one hub (hub = device that shares the single controller data lines on more ports), then yes, you suffer a speed penalty if there are data transfers around.

For example, the raspberry Pi has ONE and I repeat ONE USB controller, and all its usb ports AND ethernet share that single USB controller using a hub.

So its bandwith when using more than one device is crap.

Kirkwood devices should have more than one controller because these SoCs are designed for NAS devices, so they do need decent connectivity, but I don't know how your device is arranged.

Write "lshw" as root in your device and then look at the USB parts of the output.

This is the (relevant) output on my PC.

*-pci:5
             description: PCI bridge
             product: 6 Series/C200 Series Chipset Family PCI Express Root Port 8
             vendor: Intel Corporation
             physical id: 1c.7
             bus info: pci@0000:00:1c.7
             version: b5
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:19 memory:f7900000-f79fffff
           *-usb
                description: USB controller
                product: ASM1042 SuperSpeed USB Host Controller
                vendor: ASMedia Technology Inc.
                physical id: 0
                bus info: pci@0000:06:00.0
                version: 00
                width: 64 bits
                clock: 33MHz
                capabilities: msi msix pm pciexpress xhci bus_master cap_list
                configuration: driver=xhci_hcd latency=0
                resources: irq:0 memory:f7900000-f7907fff
              *-usbhost:0
                   product: xHCI Host Controller
                   vendor: Linux 4.4.0-0.bpo.1-amd64 xhci-hcd
                   physical id: 0
                   bus info: usb@3
                   logical name: usb3
                   version: 4.04
                   capabilities: usb-3.00
                   configuration: driver=hub slots=2 speed=5000Mbit/s
                 *-usb
                      description: Mass storage device
                      product: AS2115
                      vendor: ASMedia
                      physical id: 1
                      bus info: usb@3:1
                      logical name: scsi6
                      version: 1.00
                      serial: 20150324000652
                      capabilities: usb-3.00 scsi emulated
                      configuration: driver=usb-storage speed=5000Mbit/s
                    *-disk
                         description: SCSI Disk
                         product: AS2115
                         vendor: ASMedia
                         physical id: 0.0.0
                         bus info: scsi@6:0.0.0
                         logical name: /dev/sdb
                         version: 0
                         serial: 25600042305102
                         size: 232GiB (250GB)
                         capabilities: partitioned partitioned:dos
                         configuration: ansiversion=6 logicalsectorsize=512 sectorsize=512 signature=f2c5e006
                       *-volume
                            description: EXT4 volume
                            vendor: Linux
                            physical id: 1
                            bus info: scsi@6:0.0.0,1
                            logical name: /dev/sdb1
                            version: 1.0
                            serial: 18aa23ca-8d7c-4ec8-9717-ebf1b1700f90
                            size: 232GiB
                            capacity: 232GiB
                            capabilities: primary journaled extended_attributes large_files huge_files dir_nlink extents ext4 ext2 initialized
                            configuration: created=2016-04-02 20:14:48 filesystem=ext4 lastmountpoint=/media/aaa/18aa23ca-8d7c-4ec8-9717-ebf1b1700f90 modified=2016-04-02 21:31:12 mounted=2016-04-02 20:14:55 state=clean
              *-usbhost:1
                   product: xHCI Host Controller
                   vendor: Linux 4.4.0-0.bpo.1-amd64 xhci-hcd
                   physical id: 1
                   bus info: usb@2
                   logical name: usb2
                   version: 4.04
                   capabilities: usb-2.00
                   configuration: driver=hub slots=2 speed=480Mbit/s

This tells us that on a pcie line we have a Asmedia USB 3.0 host controller with 2 ports on which we find a usb 3.0 to sata controller and a sata drive (the last two are an external usb 3.0 hard drive, the others are inside my PC).
And there is a free USB 3.0 port.


Let's see what it looks like when there is a hub or two in the middle:

        *-usb:1
             description: USB controller
             product: 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1
             vendor: Intel Corporation
             physical id: 1d
             bus info: pci@0000:00:1d.0
             version: 05
             width: 32 bits
             clock: 33MHz
             capabilities: pm debug ehci bus_master cap_list
             configuration: driver=ehci-pci latency=0
             resources: irq:23 memory:f7c07000-f7c073ff
           *-usbhost
                product: EHCI Host Controller
                vendor: Linux 4.4.0-0.bpo.1-amd64 ehci_hcd
                physical id: 1
                bus info: usb@4
                logical name: usb4
                version: 4.04
                capabilities: usb-2.00
                configuration: driver=hub slots=2 speed=480Mbit/s
              *-usb
                   description: USB hub
                   product: Integrated Rate Matching Hub
                   vendor: Intel Corp.
                   physical id: 1
                   bus info: usb@4:1
                   version: 0.00
                   capabilities: usb-2.00
                   configuration: driver=hub slots=8 speed=480Mbit/s
                 *-usb:0
                      description: Video
                      product: Webcam C270
                      vendor: Logitech, Inc.
                      physical id: 3
                      bus info: usb@4:1.3
                      version: 0.10
                      serial: 688792E0
                      capabilities: usb-2.00
                      configuration: driver=snd-usb-audio maxpower=500mA speed=480Mbit/s
                 *-usb:1
                      description: USB hub
                      product: USB 2.0 Hub [Safe]
                      vendor: Terminus Technology Inc.
                      physical id: 4
                      bus info: usb@4:1.4
                      version: 1.00
                      capabilities: usb-2.00
                      configuration: driver=hub maxpower=100mA slots=7 speed=12Mbit/s
                    *-usb:0
                         description: USB hub
                         product: USB 2.0 Hub
                         vendor: Terminus Technology Inc.
                         physical id: 1
                         bus info: usb@4:1.4.1
                         version: 1.11
                         capabilities: usb-2.00
                         configuration: driver=hub maxpower=100mA slots=4 speed=12Mbit/s
                    *-usb:1
                         description: Mass storage device
                         product: Mass Storage Device
                         vendor: JetFlash
                         physical id: 6
                         bus info: usb@4:1.4.6
                         logical name: scsi10
                         version: 1.00
                         serial: K5F9GUI3
                         capabilities: usb-2.00 scsi emulated
                         configuration: driver=usb-storage maxpower=100mA speed=12Mbit/s
                       *-disk
                            description: SCSI Disk
                            physical id: 0.0.0
                            bus info: scsi@10:0.0.0
                            logical name: /dev/sdf
                            size: 3828MiB (4013MB)
                            capabilities: partitioned partitioned:dos
                            configuration: logicalsectorsize=512 sectorsize=512 signature=000ac81d
                          *-volume
                               description: EXT4 volume
                               vendor: Linux
                               physical id: 1
                               bus info: scsi@10:0.0.0,1
                               logical name: /dev/sdf1
                               version: 1.0
                               serial: dee291cc-84bd-466e-8f89-b07ed073d21d
                               size: 3825MiB
                               capacity: 3825MiB
                               capabilities: primary bootable journaled extended_attributes large_files huge_files dir_nlink extents ext4 ext2 initialized
                               configuration: created=2015-09-18 09:25:00 filesystem=ext4 label=rootfs lastmountpoint=/media/alby/rootfs modified=2016-04-03 00:04:38 mounted=2016-04-02 23:58:14 state=clean
                    *-usb:2
                         description: Mass storage device
                         product: USB 2.5"-HDD
                         vendor: TOSHIBA
                         physical id: 7
                         bus info: usb@4:1.4.7
                         logical name: scsi7
                         version: 1.12
                         serial: 00106c59
                         capabilities: usb-2.00 scsi emulated
                         configuration: driver=usb-storage maxpower=2mA speed=12Mbit/s
                       *-disk
                            description: SCSI Disk
                            physical id: 0.0.0
                            bus info: scsi@7:0.0.0
                            logical name: /dev/sdc
                            size: 298GiB (320GB)
                            capabilities: gpt-1.00 partitioned partitioned:gpt
                            configuration: guid=63b4c0e9-3302-49bf-9a0a-786fffe70b63 logicalsectorsize=512 sectorsize=512
                          *-volume:0
                               description: EXT4 volume
                               vendor: Linux
                               physical id: 1
                               bus info: scsi@7:0.0.0,1
                               logical name: /dev/sdc1
                               logical name: /media/alby/ext4data
                               version: 1.0
                               serial: f065e33e-e494-4e63-b499-d8a0b8405369
                               size: 35GiB
                               capabilities: journaled extended_attributes large_files huge_files dir_nlink recover extents ext4 ext2 initialized
                               configuration: created=2015-08-26 16:09:53 filesystem=ext4 label=ext4data lastmountpoint=/media/aaaa/ext4data modified=2016-04-02 20:09:57 mount.fstype=ext4 mount.options=rw,nosuid,nodev,relatime,data=ordered mounted=2016-04-02 20:09:57 state=mounted
                          *-volume:1
                               description: Windows NTFS volume
                               vendor: Windows
                               physical id: 2
                               bus info: scsi@7:0.0.0,2
                               logical name: /dev/sdc2
                               logical name: /media/aaaa/ntfsdata
                               version: 3.1
                               serial: b65f2b28-3f8d-ce4b-b333-62c3b97f1374
                               size: 262GiB
                               capacity: 262GiB
                               capabilities: ntfs initialized
                               configuration: clustersize=4096 created=2016-03-21 20:31:20 filesystem=ntfs label=ntfsdata mount.fstype=fuseblk mount.options=rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 state=mounted
                 *-usb:2
                      description: Mouse
                      product: USB Optical Mouse
                      vendor: Logitech
                      physical id: 6
                      bus info: usb@4:1.6
                      version: 63.00
                      capabilities: usb-2.00
                      configuration: driver=usbhid maxpower=100mA speed=1Mbit/s

Now, this is a USB 2.0 tree, with usb controllers and a "rate matching hub" that is a special hub that does not restrict bandwith and is part of the chipset, then you see a couple actual hubs (it is a 10-port usb 2.0 hub on my desk, they used 2 hub chips), a USB flash drive and a USB hard drive with 2 partitions connected to the hub.

Thanks for the detailed info - very useful.

I have two hdd and one flash drive in the pogoplug, all USB. They have as bus info

bus info: usb@1:1.3[\code]. Am I right in assuming that they are on one controller?

The complete output from lshw is as follow:

root@pogoplug:~# lshw
pogoplug
    description: Computer
    width: 32 bits
  *-core
       description: Motherboard
       physical id: 0
     *-memory
          description: System memory
          physical id: 0
          size: 249MiB
     *-cpu
          physical id: 1
          bus info: cpu@0
     *-scsi:0
          physical id: 2
          bus info: usb@1:1.1
          logical name: scsi0
          capabilities: emulated
        *-disk
             description: SCSI Disk
             physical id: 0.0.0
             bus info: scsi@0:0.0.0
             logical name: /dev/sda
             size: 14GiB (15GB)
             capabilities: partitioned partitioned:dos
             configuration: sectorsize=512
           *-volume:0
                description: EXT3 volume
                vendor: Linux
                physical id: 1
                bus info: scsi@0:0.0.0,1
                logical name: /dev/sda1
                logical name: /
                logical name: /exports/staging
                version: 1.0
                serial: 00e8db83-e8ab-48bf-8076-8c9f9fde2063
                size: 7GiB
                capacity: 7GiB
                capabilities: primary bootable journaled extended_attributes large_files recover ext3 ext2 initialized
                configuration: created=1970-01-01 00:21:06 filesystem=ext3 label=rootfs lastmountpoint=/media/rainerkrug/rootfs modified=1970-01-01 00:00:53 mount.fstype=ext3 mount.options=rw,noatime,errors=remount-ro,barrier=1,data=ordered mounted=1970-01-01 00:00:54 state=mounted
           *-volume:1
                description: Linux swap volume
                physical id: 2
                bus info: scsi@0:0.0.0,2
                logical name: /dev/sda2
                version: 1
                size: 1GiB
                capacity: 1GiB
                capabilities: primary nofs swap initialized
                configuration: filesystem=swap pagesize=4096
     *-scsi:1
          physical id: 3
          bus info: usb@1:1.2
          logical name: scsi1
          capabilities: emulated
        *-disk
             description: SCSI Disk
             product: FreeAgent Go
             vendor: Seagate
             physical id: 0.0.0
             bus info: scsi@1:0.0.0
             logical name: /dev/sdb
             version: 0138
             serial: 2HC015KJ
             size: 232GiB (250GB)
             capabilities: partitioned partitioned:dos
             configuration: ansiversion=4 sectorsize=512 signature=0002af98
           *-volume:0
                description: EXT4 volume
                vendor: Linux
                physical id: 1
                bus info: scsi@1:0.0.0,1
                logical name: /dev/sdb1
                logical name: /media/Music
                logical name: /exports/Music
                version: 1.0
                serial: 83728f43-e612-9dc5-f9d7-66a259999b32
                size: 222GiB
                capacity: 222GiB
                capabilities: primary bootable journaled extended_attributes large_files huge_files dir_nlink recover extents ext4 ext2 initialized
                configuration: created=2015-02-16 21:27:53 filesystem=ext4 label=Music lastmountpoint=/media/Music modified=1970-01-01 00:01:05 mount.fstype=ext4 mount.options=rw,relatime,user_xattr,acl,barrier=1,data=ordered mounted=1970-01-01 00:01:05 state=mounted
           *-volume:1
                description: EXT3 volume
                vendor: Linux
                physical id: 2
                bus info: scsi@1:0.0.0,2
                logical name: /dev/sdb2
                version: 1.0
                serial: 4ad67077-604e-4db8-bdd7-92da47b667b4
                size: 8GiB
                capacity: 8GiB
                capabilities: primary journaled extended_attributes large_files ext3 ext2 initialized
                configuration: created=2015-03-29 18:21:32 filesystem=ext3 label=rootfs_bodhi lastmountpoint=/media/rootfs modified=2015-03-30 09:01:39 mounted=2015-03-29 18:32:57 state=clean
           *-volume:2
                description: Linux swap volume
                physical id: 3
                bus info: scsi@1:0.0.0,3
                logical name: /dev/sdb3
                version: 1
                serial: 293a10f7-b560-4e60-9d4c-2be8091f748a
                size: 2GiB
                capacity: 2GiB
                capabilities: primary nofs swap initialized
                configuration: filesystem=swap label=swap pagesize=4096
     *-scsi:2
          physical id: 4
          bus info: usb@1:1.3
          logical name: scsi2
          capabilities: emulated
        *-disk
             description: SCSI Disk
             product: P9233
             vendor: LaCie
             physical id: 0.0.0
             bus info: scsi@2:0.0.0
             logical name: /dev/sdc
             version: 1053
             serial: 2801fc306b5400000000
             size: 4657GiB (5TB)
             capabilities: partitioned partitioned:dos
             configuration: ansiversion=6 sectorsize=4096
           *-volume UNCLAIMED
                description: EFI GPT partition
                physical id: 1
                bus info: scsi@2:0.0.0,1
                capacity: 582GiB
                capabilities: primary nofs
  *-network
       description: Ethernet interface
       physical id: 1
       logical name: eth0
       serial: 00:25:31:00:49:4b
       size: 1Gbit/s
       capacity: 1Gbit/s
       capabilities: ethernet physical tp aui bnc mii fibre 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=mv643xx_eth driverversion=1.4 duplex=full firmware=N/A ip=192.168.1.100 link=yes multicast=yes port=MII speed=1Gbit/s
[\code]



Rainer

=========================== 
Blog: https://rmkrug.wordpress.com/

1 x Pogoplug E02 (pink): Logitech media server

1 x Pogoplug E02 (pink): FTP server only (throw away configuration - quick to rebuild)
 
1 x GoFlex Net: running OpenMediaVault

They are on the same controller too, yes.

bus info: usb@1:1.1

and all other devices show the same. That means all are on controller 1.

Still we could have done without lshw, I forgot to check the datasheet first and my memory isn't terribly good.
Kirkwoods have only ONE usb controller.
https://origin-www.marvell.com/embedded-processors/kirkwood/assets/88F6281-004_ver1.pdf

So yeah, at this point if you need decent speed, you will have to use the goflex.

EDIT: I meant "speed", not "usb speed".



Edited 1 time(s). Last edit at 04/04/2016 05:03AM by bobafetthotmail.

OK - I have a GoFlex Net standing newxt to me and will see to it later.

Thanks,

Rainer

===========================
Blog: https://rmkrug.wordpress.com/

1 x Pogoplug E02 (pink): Logitech media server

1 x Pogoplug E02 (pink): FTP server only (throw away configuration - quick to rebuild)

1 x GoFlex Net: running OpenMediaVault