[geeks] external drive bay issues...

[Nathan Raymond]

I've personally stayed away from JMicron controllers as much as possible,
and also stayed away from enclosures where I can't update the firmware. USB
3.0, especially in the early days, was notoriously flaky. JMicron is a
fabless Taiwanese microcontroller maker who makes a lot of products at the
lower end of the market. Mediasonic makes primarily inexpensive RAID and
JBOD enclosures, so they (not surprisingly) use JMicron controllers.
Mediasonic doesn't put firmware updates for their enclosures on their
public website (which I find disappointing) but if you contact their
support, they will sometimes supply one to you directly. This is mentioned
here, for instance:

https://www.amazon.com/review/RK8DM53KY2647/ref=cm_cr_pr_viewpnt#RK8DM53KY264
7

I haven't been too impressed by some of the things I've read about Micron
controllers in places like the smartmontools wiki:

https://www.smartmontools.org/wiki/Supported_USB-Devices

Things like:

"Used in bSharkoon 5-Bay RAID Box, JMS539 - '-d usbjmicron' often causes
the disks to reset here, '-d sat' works more reliably but I have still had
disk resets (OmegaPhil). Also used in bSharkoon 5-Bay RAID Station, doesn't
work at all here (OmegaPhil) Also used in bSSI-1359RUS3 boxes, which can be
updated with the firmware in Ticket #552 which turns it into 0x152d:0x0551
and disables its annoying automatic sleep mode."

Speaking of automatic sleep, I think if you have an automatic sleep option
on your MediaSonic box that is likely to be completely unrelated to the
"sleep" on a computer. For whatever reason USB bridge chip makers have
fairly often implemented their own disk sleep/spin down timers so that
after a certain period of no data transfer their controllers will tell
connected drives to spin down (independent of any similar OS spin down
algorithms or commands). This is not a feature I've ever seen in Firewire
bridge chips, just USB, and personally I find it rather annoying if it's
not something I can control in some way, since all physical spinning disks
experience some wear from head load/unload cycles (and in some cases, some
stupid 'green' drives excessively park/unpark their heads on their own via
their own firmware in order to achieve certain pointless low-power average
benchmarks).

In my experience, ASMedia tends to make better controllers/bridge chips and
vendors that integrate them tend to offer more readily accessible firmware
updates. However you will find that even with the most recent stuff, there
are issues, such as:

http://www.anandtech.com/show/10844/cru-toughtech-duo-c-storage-enclosure-2x-
25-to-usb-31-gen-2-typec-capsule-review/4

"Storage bridges that support UASP fully can translate the SCSI UNMAP
command to TRIM commands for SSDs connected to the downstream port... Given
that TRIM support doesn't exist even for JBOD configuration, there is no
point testing out the RAID configurations. CRU indicated that they are
waiting for support from ASMedia to issue a firmware update with TRIM
support. So, it is conceivable that we will be able to get TRIM support in
the future for the JBOD configuration, at the least."

Which is an example of why even now with brand new products firmware
updates and vendor support is important.

- Nate

On Thu, Dec 8, 2016 at 7:52 AM, Charles Shannon Hendrix <
shannon at widomaker.com> wrote:

> I bought a Mediasonic 4-bay JBOD array awhile back. It worked fine on a
> Windows machine and a NAS box, though it only had a single drive in it.
>
> I retired my Mac Pro and so I put it on my new iMac with 4 drives:
>
> - 1 SSD
> - 1 4TB Seagate
> - 2 3TB HGST NAS drives in, AppleRAID mirrors
>
> The unit works fine, except when the computer goes to sleep. Upon waking,
> there is a high chance that the drives disappear.
>
> A couple of times, I have had drives disappear randomly.
>
> It seems like every time this happened, the Seagate driveb s LED would be
> flashing continuously, while the other drives were silent. I tested the
> Seagate and it passes everything, SMART looks OK, and it had been running
> in
> an Insignia case for months.
>
> So I read a lot about the issue, and some people say the fault lies with
> macOS. Several people have pointed at Appleb s more aggressive hibernation
> code which hibernates the machine after a sleep period has passed. This
> evidently attempts to shut down USB and Thunderbolt chipsets because they
> draw
> a lot of power.
>
>
> So I used pmset to extend the sleep period to 24-hours, making it unlikely
> the
> machine would hibernate.
>
> That seemed to fix the problem for some time, but this morning when I got
> up I
> got four messages about drives being ejected improperly. Looking at the
> unit
> the mirror and the SSD were missing and the Seagateb s LED was flashing
> continuously.
>
> Sob& Ib m trying to figure out what the problem is. If this is a general
> macOS issue, that sucks because it has been an issue since Mavericks was
> released.
>
> The fact that the Seagateb s drive bay is flashing every time this happens,
> does make me suspicious of that drive. Maybe it has some firmware issues
> and
> canb t run in that JBOD, I donb t know. Having said that, I read in a
> couple
> of places that doesnb t mean anything, its just that some drives get hung
> in
> a read loop when a USB or Thunderbolt controller fails.
>
> I donb t really know much about the Mediasonic. It uses a fairly
> bog-standard
> JMicron USB/SATA controller and doesnb t have any kind of software. It has
> a
> switch that controls how it reacts to the computer going to sleep, and
> putting
> it on b never sleepb  doesnb t help the issue.
>
> Anyway, I thought I would post my observations here for commentary and
> suggestions.
>
> I sent a question to OWC about it, asking them if they were aware of issues
> like that with their own external units, because it wouldnb t do me any
> good
> to replace the Mediasonic if their own units are having the issue. Web ll
> see
> what they say about it.
>
>
>
>
> --
> "Where some they sell their dreams for small desires."
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