Posts by edwardwong

    HP N54L only do well on transcoding 720p video (most, but not all), 1080p doesn't work all (that's the reason I rebuild another one after getting N54L)

    Probably getting a HP Gen 8, with a Xeon CPU swap (preferably a low voltage Xeon E3 as original heat sink only supports CPU with TDP <= 35W) can be a good idea. I saw it's cheap on Computer Universe.

    root@openmediavault:~# hdparm -C /dev/sdb

    drive state is: active/idle
    root@openmediavault:~# hdparm -C /dev/sdc

    drive state is: standby
    root@openmediavault:~# hdparm -C /dev/sda

    drive state is: active/idle

    sda is the OS drive, sdb is the mounted drive (ZFS), sdc is unformatted drive

    In physical disk section, I already chose the power management options for all data disks, I logged out from the system for > 40mins (I configured the standby time to be 20min) but still feel one of the drive boiling, the other one without any mount point is good (both are same model), is there anyway I can let the drive with mount point sleep/standby?

    Just tested Plex transcoding, the result is very promising 8) :
    I downloaded a few H.264 videos, including 1080p/2K/4K video, to ensure transcoding is happening I manually chose 480p@1.5M, or 720p@3M/4M, or 1080p@10M/20M (because within LAN environment they might think raw transmission without transcoding is possible)

    1. Tested with 1080p video, everything fine, I can transcode 2 at the same time without any issue (didn't try > 2 as it would be very rare to do this) :thumbup:
    2. Tested with 2K video, also good, it took a bit more time to start (I can understand), later I tried to add one more 1080p transcoding stream at the same time, the machine is able to handle all smoothly :thumbsup: !! System load 8.50, I got kernel message "machine error check" in dmesg frequently, I know it's cpu core overheating, causing cpu clock throttling to avoid damage, as client sides do have their buffer, so a very short period of cpu clock dropping won't hurt.
    3. Tested with 4K video, no luck :thumbdown: , every 15-20 sec there will be a long pause (5-10 sec), obviously my machine is unable to handle this, but I don't really mind as I believe when 4K becomes common, I already swapped my machine with other hardware already. For people who owned the big brother of mine (Avoton C2750, 8-core) should be able to do this.

    Anyway, for a processor with TDP only 14W, what else you are expecting? :D

    Atom may not be fast enough to transcode. If you are just serving files, it will work well.

    This ATOM C2750 SoC is different story, with all 8-core active (multi-thread), it's processing power can reach about 50% of a lower end Xeon E3.
    I owned the little brother, C2550, which is of same spec expect mine is 4-core only, I just tried with my OMV with Plex transcoding, it can handle 1 x H.264@1080p + 1 x H.264@2K (both were asked to transcode to 480p 1.5M or 720p 3M bitrate), so I believe C2750 can do more. (Someone in Plex forum mentioned that he can do 4 x 1080p transcoding without any issue.


    Personally, I think filters are a waste of time. They may keep dust out of your system but they become blocked off restricting air flow. It isn't hard to blow the dust out of a system every few months.

    opening case from somewhere full of stuff stacking around might not be fun :P
    I stick some filter outside the case (not very good looking), in case it's full of stuff then I just peel off them and put a new one, of course I will still open the case for cleaning, but probably once a year......
    The problem for OP's mobo is, passive cooling heat sink, a layer of dust on top might cause some trouble as the CPU is already 55-60C without much loading.

    There is another problem with the ZFS on 1.16 extra after installing the pluging (thanks for the bug fix):

    When I clicked ZFS on left column, I get a prompt about "Failed to load ZFS module stack.Load the module manually by running 'insmod /zfs.ko'" (not exact wording, because I fixed the problem later so I couldn't get back original message :P )

    Running "find / -name zfs.ko" returns nothing, trying to make ZFS myself under /usr/src/zfs-0.6.3 and I was warned that "This will break ZFS", ok....

    Trying to re-install zfs-dkms, I get the below error:

    OK.....I checked that "spl-dkms" is also installed, weird.....

    Then I looked around on internet, I found something insteresting: Some people realized that spl-dkms has to be configured before zfs-dkms, so I tried following:

    Looks promosing, to verify.....

    root@openmediavault:~# find / -name zfs.ko

    Bravo! Now I won't get any error when clicking into ZFS in GUI.
    Will this be addressed in the installer?


    I am installing iSCSI plugin from plugin page, but getting the following error prompt after installation, I have no idea what it is, anyone can shed me some light? Thanks.

    Error #3003:
    exception 'OMVException' with message 'Failed to get configuration (xpath=//services/iscsitarget)' in /usr/share/openmediavault/engined/module/
    Stack trace:
    #0 /usr/share/openmediavault/engined/rpc/ OMVModuleIscsiTarget->getStatus()
    #1 [internal function]: OMVRpcServiceServices->getStatus(Array, Array)
    #2 /usr/share/php/openmediavault/ call_user_func_array(Array, Array)
    #3 /usr/share/php/openmediavault/ OMVRpcServiceAbstract->callMethod('getStatus', Array, Array)
    #4 /usr/sbin/omv-engined(500): OMVRpc::exec('Services', 'getStatus', Array, Array, 1)
    #5 {main}

    A month ago I bought the HP Microserver N54L when I had my vacation in Japan and price was only around JPY 15,000 which is fairly cheap, but I was not satisfied with it pretty soon because:

    1. Not enough drive bay, even with ODD I can only have max. 6 drives (5 x 3.5" + 1 x 2.5")
    2. CPU issue - I want to do Plex transcoding, AMD N54L works well on most video up to 720p (actually not all 720p), but not for 1080p, I don't need to have many transcoding streams, 1-2 full HD will be good enough. And this AMD CPU has no AES acceleration, encryption speed is slow.

    I started to look for some alternatives, I need to keep it low power (means less heat, I don't want to hear fans spinning full speed all the time), capable to host more drives but better to have smaller size, after a week of research I came up with these:

    Motherboard + memory: Asrock C2550D4i, Intel quad-core Avoton SoC C2550, with TDP 14W only! One of the brilliant feature is the on board 12 SATA ports (8 x SATA 6Gbps + 4 x SATA 3Gbps)! According to some other forums it's bigger brother C2750 (octa-core) is able to transcode 4 1080p flawlessly, so mine should be good for at lease 1 people. All 4 memory slots filled with Crucial 4GB ECC DDR3-1333, total 16GB (looking forward to use ZFS/BtrFS on OMV so be prepared well on this first), and these memory were actually removed from old workstations. (There is downside of this board USB 3.0, even for USB 2, only 2 at the back and 1 header inside, probably a trade off for getting more SATA)

    Case: Lian-Li PC-Q25, this one is not too big compared with HP N54L, but it has a backplane capable to host 5 x 3.5" hot pluggable drives, and it's base also allowing extra 2 x 3.5" + 1 x 2.5" drives. You'll have to open the side cover in order to remove disk, but Lian Li already had a design that you don't have to deal with screws on both side cover. This case takes normal ATX PSU.

    Misc: Internal SATA to eSATA converter (good for future expansion) + Intel Pro/1000 PT Server Dual Port PCI-e x4 (also got it from old servers), together with onboard 2 x Intel i210 GbE, now I have 4 NICs, planning to use it for iSCSI MC/S.

    Just popped in some drives for testing, here is how the new setup looks like:

    I replaced the original fixed RPM 12cm fan (I don't need full speed all the time, it's too noisy) with Noctua 12cm PWM fan, and to allow better ventilation, I bought ATX-SFX adaptor so that I can mount my old 250W SFX PSU.

    The C2550D4i motherboard actually has an IPMI interface, allowing me to remote control the power, monitor system, it also supports drive image redirection & remote console, so as long as I have another file server (I do have an old Synology NAS serving many years) and IPMI is plugged into network, I can do installation remotely.

    My first trial on Plex with new build: 1080p video (sample video downloaded from internet) transcoding absolutely no problem, with a peak system load 3.5 then keep ing at 1.6-1.8 all the time (I forced server to transcode it to 720p/480p video), so I believe running 2 Plex video streams should be fine. 4K sample video was also tested, core temperature rose to 98C very soon, causing CPU throttling (and of course video lag), a system load of around 6.5 (!) was recorded, I believe I need it's bigger brother in order to transcode 4K video, or employ water cooling to the current CPU (which is not what I want)

    This ATOM processor has AES-NI feature, I would be benefited from any AES encryption/decryption. My primary usage will be video storage + realtime transcoding + serving as an iSCSI target to a Mac Pro + planned to run OwnCloud to sync all devices to NAS for data protection.

    Any comment?

    My first post here...

    What a good topic, I was looking for some way that I can reduce disk I/O (because I want to make use of CF card as OS drive)
    To me, reducing disk IO, means more chance to let drive to spin down, less heat/noise? And if possible for a USB memory installation a SATA port can be saved as well!

    But I do have a question, for the fs2ram, I don't see there is any setting to flush memory content to disk, did I missed something?