I could do with re-instating a 24x7 server on a Pi instead of on a beefy server
where it used to run, I keep worrying that because it uses mySQL it'll probably
do more writes than are healthy for an SD card.

Has anyone used the Western Digital Purple SD cards that are supposed to include
wear levelling like a "proper" SSD?

On 10/10/2022 13:24, Andy Burns wrote:
> I could do with re-instating a 24x7 server on a Pi instead of on a beefy
> server where it used to run, I keep worrying that because it uses mySQL
> it'll probably do more writes than are healthy for an SD card.
>
> Has anyone used the Western Digital Purple SD cards that are supposed to
> include wear levelling like a "proper" SSD?
>
>

Use a USB attached SSD as your root (/) device. Just use the SD card for
/boot

--
Chris Elvidge
England

Chris Elvidge <chris@mshome.net> wrote:
> Just use the SD card for /boot

No need; rpi 2, 3 and 4 can boot directly from usb. See
https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#usb-mass-storage-boot

On Mon, 10 Oct 2022 13:56:08 +0100, Chris Elvidge
<chris@mshome.net> wrote:

> Use a USB attached SSD as your root (/) device. Just use the SD card for
> /boot

+1
Works perfectly. (in my case with a low-power 2.5" USB harddrive
instead of an SSD)
--
Kees Nuyt

Chris Elvidge wrote:

> Andy Burns wrote:
>
>> Has anyone used the Western Digital Purple SD cards that are supposed to
>> include wear levelling like a "proper" SSD?
>
> Use a USB attached SSD as your root (/) device. Just use the SD card for /boot

Not sure the PoE can handle enough power for an external disc, sorry forgot to
mention that ...

On 2022-10-10, Andy Burns <usenet@andyburns.uk> wrote:
> Chris Elvidge wrote:
>
>> Andy Burns wrote:
>>
>>> Has anyone used the Western Digital Purple SD cards that are supposed to
>>> include wear levelling like a "proper" SSD?
>>
>> Use a USB attached SSD as your root (/) device. Just use the SD card for /boot
>
> Not sure the PoE can handle enough power for an external disc, sorry forgot to
> mention that ...
>

What power can your PoE setup deliver. I have a pi3 and a 3inch USB
connected harddrive powered by the old "standard" 5V 2A Pi power supply
and there's no problem. A small SSD should take less power.

Hello Andy!

Monday October 10 2022 13:24, you wrote to All:

> I could do with re-instating a 24x7 server on a Pi instead of on a
> beefy server where it used to run, I keep worrying that because it
> uses mySQL it'll probably do more writes than are healthy for an SD
> card.

> Has anyone used the Western Digital Purple SD cards that are supposed
> to include wear levelling like a "proper" SSD?

I would NOT recommend any SD card for any system that has a reasonable amount
of write / reads - it it best to use a usb attached hard drive or a GOOD SSD
such as Samsung 850, 950, 960 or later series devices as they use strong
controllers that can handle garbage collection via fstrim without needed to be
idle.

Vincent

In message <jqiqajFebl8U2@mid.individual.net>, Andy Burns
<usenet@andyburns.uk> writes
>Chris Elvidge wrote:
>
>> Andy Burns wrote:
>>
>>> Has anyone used the Western Digital Purple SD cards that are
>>>supposed to include wear levelling like a "proper" SSD?
>> Use a USB attached SSD as your root (/) device. Just use the SD card
>>for /boot
>
>Not sure the PoE can handle enough power for an external disc, sorry
>forgot to mention that ...
>
>

I've been running a Pi2 and a Pi3 with Samsung 1TB SSDs attached (one on
each) for over a year with no problems, both Pis are using the usual
2.5A Pi power supply.

Adrian
--
To Reply :
replace "bulleid" with "adrian" - all mail to bulleid is rejected
Sorry for the rigmarole, If I want spam, I'll go to the shops
Every time someone says "I don't believe in trolls", another one dies.

Jim Jackson wrote:

> Andy Burns wrote:
>
>> Not sure the PoE can handle enough power for an external disc, sorry forgot to
>> mention that ...
>
> What power can your PoE setup deliver.

2.4A @ 5V

> I have a pi3 and a 3inch USB
> connected harddrive powered by the old "standard" 5V 2A Pi power supply
> and there's no problem. A small SSD should take less power.

mine's a 3B, I've got various drives and enclosures knocking about, if only I
knew which county the spare PoE extractor was in ...

On 2022-10-10, Andy Burns <usenet@andyburns.uk> wrote:
> Jim Jackson wrote:
>
>> Andy Burns wrote:
>>
>>> Not sure the PoE can handle enough power for an external disc, sorry forgot to
>>> mention that ...
>>
>> What power can your PoE setup deliver.
>
> 2.4A @ 5V
>
>> I have a pi3 and a 3inch USB
>> connected harddrive powered by the old "standard" 5V 2A Pi power supply
>> and there's no problem. A small SSD should take less power.
>
> mine's a 3B, I've got various drives and enclosures knocking about, if only I
> knew which county the spare PoE extractor was in ...
>

Sounds like it will work.

Vincent Coen <nospam.Vincent.Coen@f1.n250.z2.fidonet.org> wrote:
> Hello Andy!
>
> Monday October 10 2022 13:24, you wrote to All:
>
> > I could do with re-instating a 24x7 server on a Pi instead of on a
> > beefy server where it used to run, I keep worrying that because it
> > uses mySQL it'll probably do more writes than are healthy for an SD
> > card.
>
> > Has anyone used the Western Digital Purple SD cards that are supposed
> > to include wear levelling like a "proper" SSD?

I haven't seen the WD Purple cards before, but I'd be concerned that they're
intended for streaming, ie large sequential writes. It's possible they
manage that with a large flash block size, and that writing a database will
cause a lot of write amplification.

That should show up by having a low random write speed. Here's some
benchmarks of the card, but no random write test:
https://www.reddit.com/r/raspberry_pi/comments/ex7dvo/quick_reminder_that_sd_cards_with_wearleveling/

The WD statement is a bit confusing, but includes "We cannot recommend you
use this product to install an operating system despite of its durability,
reliability and performance."

> I would NOT recommend any SD card for any system that has a reasonable amount
> of write / reads - it it best to use a usb attached hard drive or a GOOD SSD
> such as Samsung 850, 950, 960 or later series devices as they use strong
> controllers that can handle garbage collection via fstrim without needed to be
> idle.

+1. Proper SSD controllers are miles apart from SD cards. I don't think
this one is going to change that.

Theo

On 10 Oct 2022 21:56:21 +0100 (BST), Theo wrote:

> Vincent Coen <nospam.Vincent.Coen@f1.n250.z2.fidonet.org> wrote:
>> Hello Andy!
>>
>> Monday October 10 2022 13:24, you wrote to All:
>>
>> > I could do with re-instating a 24x7 server on a Pi instead of on a
>> > beefy server where it used to run, I keep worrying that because it
>> > uses mySQL it'll probably do more writes than are healthy for an SD
>> > card.
>>
>> > Has anyone used the Western Digital Purple SD cards that are
>> > supposed to include wear levelling like a "proper" SSD?
>
> I haven't seen the WD Purple cards before, but I'd be concerned that
> they're intended for streaming, ie large sequential writes. It's
> possible they manage that with a large flash block size, and that
> writing a database will cause a lot of write amplification.
>
You've hit it in one:its designed for use in surveillance cameras and is
in speed class 10 - this is the same class as SD cards intended for use in
video cameras, so likely to use a large block size and intended toy
sequential writes (and reads) rather than random access.
> That should show up by having a low random write speed. Here's some
> benchmarks of the card, but no random write test:
> https://www.reddit.com/r/raspberry_pi/comments/ex7dvo/
quick_reminder_that_sd_cards_with_wearleveling/
>
No numbers are given on the WD spec sheet I found apart from:
- capacities 32GB - 1TB,
- warranty 3 years
- operating temp -25C - 85C
- storage temp -40C - 85C

As others have already suggested, best to look at USB-connected spinning
rust or SSD drives.

--

Martin | martin at
Gregorie | gregorie dot org

On 10/10/2022 13:56, Chris Elvidge wrote:
> On 10/10/2022 13:24, Andy Burns wrote:
>> I could do with re-instating a 24x7 server on a Pi instead of on a
>> beefy server where it used to run, I keep worrying that because it
>> uses mySQL it'll probably do more writes than are healthy for an SD card.
>>
>> Has anyone used the Western Digital Purple SD cards that are supposed
>> to include wear levelling like a "proper" SSD?
>>
>>
>
> Use a USB attached SSD as your root (/) device. Just use the SD card for
> /boot
>
That is my instant kneejerk reaction, too.

--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."

Lucas Bergkamp

"Jim Jackson" <jj@franjam.org.uk> wrote in message
news:slrntk8efd.6rs.jj@iridium.wf32df...
> On 2022-10-10, Andy Burns <usenet@andyburns.uk> wrote:
>> Chris Elvidge wrote:
>>
>>> Andy Burns wrote:
>>>
>>>> Has anyone used the Western Digital Purple SD cards that are supposed
>>>> to
>>>> include wear levelling like a "proper" SSD?
>>>
>>> Use a USB attached SSD as your root (/) device. Just use the SD card for
>>> /boot
>>
>> Not sure the PoE can handle enough power for an external disc, sorry
>> forgot to
>> mention that ...
>>
>
> What power can your PoE setup deliver. I have a pi3 and a 3inch USB
> connected harddrive powered by the old "standard" 5V 2A Pi power supply
> and there's no problem. A small SSD should take less power.

I found that a typical spinning USB HDD (2.5") made my Pi 3B+ run very hot
if the drive was powered from the Pi from the RasPi PSU that was providing
with the 3B+. Sometimes the HDD did not even start spinning. Instead I
powered the HDD from an external powered USB bus.

Sadly the same USB bus would not work when I upgraded to a Pi 4. There seems
to be something in the Pi 4 which causes booting to hang at a very early
stage if the USB bus is powered before or at the same time as the Pi (as
would happen if the power came on after a power cut). (*) As soon as power
was removed from USB bus (or the bus was unplugged from the Pi's USB) the Pi
immediately began the boot process, and once it had begin, I could replug
the USB bus. I had to change to an an external SATA drive in a powered
caddy.

To reduce power consumption (I think it's about 7 W, 24/7, for the powered
caddy+drive) I'm thinking about changing to a USB-powered SSD, powered from
the Pi.

(*) Asking on forums, I found that other people had experienced the same
thing with some USB hubs. One suggestion was that the Pi didn't like it if
the hub applied power on the USB lead to the Pi before the Pi's own power
came on, so I made up a special lead with the +5V line cut, but that made no
difference in my case.

On Tue, 11 Oct 2022 10:40:03 +0100, NY wrote:

> "Jim Jackson" <jj@franjam.org.uk> wrote in message
> news:slrntk8efd.6rs.jj@iridium.wf32df...
>> On 2022-10-10, Andy Burns <usenet@andyburns.uk> wrote:
>>> Chris Elvidge wrote:
>>>
>>>> Andy Burns wrote:
>>>>
>>>>> Has anyone used the Western Digital Purple SD cards that are
>>>>> supposed to include wear levelling like a "proper" SSD?
>>>>
>>>> Use a USB attached SSD as your root (/) device. Just use the SD card
>>>> for /boot
>>>
>>> Not sure the PoE can handle enough power for an external disc, sorry
>>> forgot to mention that ...
>>>
>>>
>> What power can your PoE setup deliver. I have a pi3 and a 3inch USB
>> connected harddrive powered by the old "standard" 5V 2A Pi power supply
>> and there's no problem. A small SSD should take less power.
>
> I found that a typical spinning USB HDD (2.5") made my Pi 3B+ run very
> hot if the drive was powered from the Pi from the RasPi PSU that was
> providing with the 3B+. Sometimes the HDD did not even start spinning.
> Instead I powered the HDD from an external powered USB bus.
>
> Sadly the same USB bus would not work when I upgraded to a Pi 4. There
> seems to be something in the Pi 4 which causes booting to hang at a very
> early stage if the USB bus is powered before or at the same time as the
> Pi (as would happen if the power came on after a power cut). (*) As soon
> as power was removed from USB bus (or the bus was unplugged from the
> Pi's USB) the Pi immediately began the boot process, and once it had
> begin, I could replug the USB bus. I had to change to an an external
> SATA drive in a powered caddy.
>
Has a bug been raised for this problem?

--

Martin | martin at
Gregorie | gregorie dot org

On a sunny day (Tue, 11 Oct 2022 10:40:03 +0100) it happened "NY"
<me@privacy.invalid> wrote in <ti3dnc$131uu$1@dont-email.me>:

>I found that a typical spinning USB HDD (2.5") made my Pi 3B+ run very hot
>if the drive was powered from the Pi from the RasPi PSU that was providing
>with the 3B+. Sometimes the HDD did not even start spinning. Instead I
>powered the HDD from an external powered USB bus.
>
>Sadly the same USB bus would not work when I upgraded to a Pi 4. There seems
>to be something in the Pi 4 which causes booting to hang at a very early
>stage if the USB bus is powered before or at the same time as the Pi (as
>would happen if the power came on after a power cut). (*) As soon as power
>was removed from USB bus (or the bus was unplugged from the Pi's USB) the Pi
>immediately began the boot process, and once it had begin, I could replug
>the USB bus. I had to change to an an external SATA drive in a powered
>caddy.
>
>To reduce power consumption (I think it's about 7 W, 24/7, for the powered
>caddy+drive) I'm thinking about changing to a USB-powered SSD, powered from
>the Pi.
>
>
>
>(*) Asking on forums, I found that other people had experienced the same
>thing with some USB hubs. One suggestion was that the Pi didn't like it if
>the hub applied power on the USB lead to the Pi before the Pi's own power
>came on, so I made up a special lead with the +5V line cut, but that made no
>difference in my case.

I use 2 Pi4s with 3.5 TB USB Toshiba drives
one recording security cams 24/7 and audio, the other one as webbrowser with Chrome and Firefox.
The trick is to use USB hubs, am using 2 Sitecom USB hubs, those have their own power supply and
supply the USB hardisks and some other USB stuff.

On 11/10/2022 10:49, Martin Gregorie wrote:
> On Tue, 11 Oct 2022 10:40:03 +0100, NY wrote:

>> Sadly the same USB bus would not work when I upgraded to a Pi 4. There
>> seems to be something in the Pi 4 which causes booting to hang at a very
>> early stage if the USB bus is powered before or at the same time as the
>> Pi (as would happen if the power came on after a power cut). (*) As soon
>> as power was removed from USB bus (or the bus was unplugged from the
>> Pi's USB) the Pi immediately began the boot process, and once it had
>> begin, I could replug the USB bus. I had to change to an an external
>> SATA drive in a powered caddy.
>>
> Has a bug been raised for this problem?

I tried to raise this as a bug via the RasPi forum, but didn't get any
responses or official interest. The only suggestion was the one to cut
the +5V line of the USB cable to prevent the powered USB hub from
back-powering the Pi, which was a plausible explanation of the problem
but not one that turned out to be a fix.