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Re: considering a new system and a sshd hybrid drive



at bottom :-

On 30/12/2019, Alexander V. Makartsev <avbetev@gmail.com> wrote:
> On 29.12.2019 15:49, shirish शिरीष wrote:
>> Hi all,
>>
>> I read Alexander's reply with interest at [1] .
>>
>> @Alexander, thank you for taking time to answer my question/s . Maybe
>> you can CC me the next time :)
>>
>> What was also interesting in your answer was the use of dark marketing
>> practises used by some manufacturers to disguise TLC (3-bit NAND)
>> memory chips as MLC ones but haven't shared either literature or any
>> tools to tell them apart.
>>
> Worst offender of this trickery is Samsung. You have to carefully read
> through full specifications for each device that available on official
> web sites, which are often hidden behind very long page scrolls and many
> clicks.
> Basically, if it says "4-bit" it means drive was build with QLC NAND
> type. And if it says "3-bit" it means TLC NAND type. And if it says
> "2-bit" it means MLC NAND type.
> And if some information is not available on official web site of some
> manufacturer, personally I'd search for another SSD elsewhere.
> There are also utilities that can view exact specifications of SSD, but
> I don't know if similar programs exist for Linux. [1]
> These kinds of utilities rely on internal database of known devices
> (nand chips, controllers, SSDs), so they can't simply identify any and
> all SSDs as is.
> If you have identified exact NAND chip and its manufacturer you can look
> up specifications for chips alone to see their, for an example, write
> endurance, which varies and could be different for each NAND type. [2]
>
>> You shared something called TBW or DWPD ratings for SSD but again
>> didn't share anything about that. Any links or literature which will
>> help me find a bit more about them and perhaps what you have used it
>> for ?  My workload varies, sometimes it is compiling, sometimes it is
>> running some tests, sometimes doing gaming and sometimes just browsing
>> and using multimedia (movies etc.) . So my idea and stress would be
>> general system improvements and response times. Also my budget is not
>> that great, at the most I could afford is either a 500 GB to 1 TB
> There is a good article to read about this. [3]
>>
>> I have also been reading about multi-actuator heads [2] in traditional
>> HDD's but guessing they will be probably be priced and used by
>> enterprise more rather than the enthusiast class at least in the
>> beginning. I also have read blackbaze hdd failures to get some ideas
>> about what's good or not even though their use-case scenario is far
>> bigger than mine.[3]
>>
>> For e.g. for me the question would be how to deal with backups and
>> crashes if a time comes, as checking 4 TB hdd's is also insane, at
>> least in my puny setup.
>>
>> Looking forward to know more.
>>
>> 1. https://lists.debian.org/debian-user/2019/12/msg00726.html
>> 2.
>> https://blog.seagate.com/craftsman-ship/multi-actuator-technology-a-new-performance-breakthrough/
>> 3. https://www.backblaze.com/blog/hard-drive-reliability-stats-q1-2016/
>>
> Personally, I use self-hosted NAS with RAID1 build from 2x 4TB NAS grade
> HDDs. Because I like to keep my data private and I like the idea of
> giving up storage space of one HDD drive as insurance for data safety.
> From my personal experience over many years, I can see how HDDs could
> fail in many different ways, long before SMART will mark them as "Failed".
> But it is very unlikely (and unfortunate) to buy a brand new HDD that
> will fail during it's warranty period, and if it worked fine before
> chances are high it will continue to work for many years after warranty
> period expires.
> Fun fact: I still have my ~20 years old 3.5" Fujitsu 20GB IDE HDD that
> is still alive and kicking. :)
>
> [1] http://aezay.dk/aezay/ssdz/
> [2] https://en.wikipedia.org/wiki/Flash_memory#Write_endurance
> [3]
> https://techcommunity.microsoft.com/t5/Storage-at-Microsoft/Understanding-SSD-endurance-drive-writes-per-day-DWPD-terabytes/ba-p/426024
>
> --
> With kindest regards, Alexander.
>
> ⢀⣴⠾⠻⢶⣦⠀
> ⣾⠁⢠⠒⠀⣿⡁ Debian - The universal operating system
> ⢿⡄⠘⠷⠚⠋⠀ https://www.debian.org
> ⠈⠳⣄⠀⠀⠀⠀
>

Hi all,

I was looking at debian-user December thread and missed Alexander's
further reply at [1]
The ssd-z utility [2]  he shared seems interesting. Sadly, I would
missed it as I'm not subscribed to the list.

It took me sometime but remembered usb-modeswitch [3] and
usb-modeswitch-data [3] which basically did and does something similar
for usb modems. IIRC, the data package has details on low-level
hardware stuff (IRQ addresses and such) so that the user can just fill
in the details and just run it. The usb-modeswitch package was cool as
I was able to query the device and share the details of my hardware
with the maintainer in 2009 ish.

I remember as did use MTS Blaze and do have a Reliance Jio dongle
which behaves similarly as well (although don't use it as much
nowadays.) This is strictly to be used while travelling.

1. https://lists.debian.org/debian-user/2019/12/msg00767.html
2. http://aezay.dk/aezay/ssdz/
3. https://tracker.debian.org/pkg/usb-modeswitch
4. https://tracker.debian.org/pkg/usb-modeswitch-data

-- 
          Regards,
          Shirish Agarwal  शिरीष अग्रवाल
  My quotes in this email licensed under CC 3.0
http://creativecommons.org/licenses/by-nc/3.0/
http://flossexperiences.wordpress.com

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