Author Topic: SD card flash life on Wx programs using Raspberry Pi  (Read 6611 times)

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Offline miraculon

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SD card flash life on Wx programs using Raspberry Pi
« on: October 03, 2015, 08:48:17 AM »
I just replaced my SD card after experiencing problems with GUI log-in, graphs, HTML displays and general malaise with the meteohub based system. With the new SD card, everything is working as it should.

This was about a year and a half of operation. Meteohub is handling the data from several ISSs. I don't know if this puts more wear and tear on the flash than a simple single weather station system or not.

Has anyone else had to replace their SD card on their RaspPi yet? I also had another unit out in the garage that ran a camera and some PiFace utilities previously. This unit has been repurposed for another meteohub station monitoring a VUE console.

I found some "industrial grade" SD cards, especially the Panasonic one with SLC-lite technology.

They claim:
Quote
The QE Series adopts MLC NAND flash memory with "SLC (Single Level Cell) Lite" access mode that provides higher endurance, data retention and power fail robustness than standard MLC products. An extended operating temperature
range of -25C to +85C is suitable for various applications. The integrated enhanced controller ensures long lifetime use and high system performance. Quality is maintained with 100% product screening before shipment to achieve low
failure rate. Storage capacity options include 4GB, 8GB and 16GB models

The true SLC SD card is $253, so that is too much. The SLC-Lite 16GB is $63, which is almost twice what the Pi board costs! If I have to go through this SD card replacement excercise again, I just might try it anyways.

Greg H.


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Offline Bushman

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #1 on: October 03, 2015, 09:06:23 AM »
I am moving all my Pis to USB stick OS.  http://myblog.furnissathome.co.uk/?p=384
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Offline miraculon

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #2 on: October 03, 2015, 09:37:51 AM »
Thanks for the tip and link. It seems that SD card corruption is common on the Pi. Fundamentally, though, the USB stick could suffer from the same issue couldn't it? The USB sticks have flash memory that is accessed via USB instead of the SD card's interface.

I found this on Wikipedia (although I was aware of the read/write life issue before):
Quote
Longevity

The memory in flash drives is commonly engineered with multi-level cell (MLC) based memory that is good for around 3,000-5,000 program-erase cycles,[45] but some flash drives have single-level cell (SLC) based memory that is good for around 100,000 writes. There is virtually no limit to the number of reads from such flash memory, so a well-worn USB drive may be write-protected to help ensure the life of individual cells.

Estimation of flash memory endurance is a challenging subject that depends on the SLC/MLC/TLC memory type, size of the flash memory chips, and actual usage pattern. As a result, a USB flash drive can last from a few days to several hundred years.[46]

Regardless of the endurance of the memory itself, the USB connector hardware is specified to withstand only around 1,500 insert-removal cycles.[47]

This Multi-Level Cell memory may be the Achilles heel of running weather programs on the Pi.

With "3,000-5,000 program-erase cycles" as the life for MLC, using a RPi for a weather program sounds doomed from the start...

Maybe a USB HDD might work? Or maybe I will just treat it like my Davis DFARS fan, just part of an annual ritual..

Greg H.


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Offline Bushman

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #3 on: October 03, 2015, 11:49:03 AM »
I've read that about USB but I can tell you I have NEVER experienced a USB stick failure.  SD cards OTOH....  (never buy Kingston BTW).  An HD or an SSD would definitely work.  But they cost much more than the Pi itself (for a large one)  I was looking  at making a Pi into a NAS; could run the OS and the storage of the same drive.  BTW, you should clone whatever you use so that downtime is minimized.
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Offline nincehelser

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #5 on: October 03, 2015, 02:31:58 PM »
I had problems early on due to voltage drops during writes.  Once I learned to use a more beefy power supply, my problems went away.  In other words, some generic cell-phone power adapters are just too wimpy for use with the Pi, especially if you have power-hungry devices attached to the USB ports.

Quality SD cards (actually all better flash-based devices) use wear-leveling algorithms, so it's typically not a huge concern.  The bigger the memory, the more the wear gets spread out.

I used to deploy USB flash drives by the hundreds at a time.  Once I got a generic lot that was extremely susceptible to "bit rot".  You'd could write data to them and verify that it was correct, but within a few days they would just randomly corrupt while sitting idle.   Fortunately I haven't seen that same problem for a long time.

Offline miraculon

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #6 on: October 03, 2015, 03:29:08 PM »
Quote
a more beefy power supply

How much beefiness should I be looking for? 2A, more? What did you end up with for sufficient write/erase current from the USB supply?

I would appreciate knowing a good value, so I don't have to reinvent the wheel....

Greg H.


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Offline weatherc

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #7 on: October 03, 2015, 03:56:05 PM »
I runned a Pi on my remote station first running WeeWx. It just caused problems all the time, all kind of odd crashes and hangups. Then i put few more bucks to the show and bought a "Pi-cousin", Cubieboard Cubietruck and a 32 G SSD as external disk and no issues since that. Re poweusage, that combo uses ca 1 watt (0.2 A) as average.

In addition to collecting the weatherdata from the VP2 it also grabs/manage the IP-cam image (reduce its size, adding wxdata on it + uploading the pic) and collecting and uploading data from the solarpanel controller.
« Last Edit: October 03, 2015, 04:24:57 PM by weatherc »

Offline nincehelser

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #8 on: October 03, 2015, 03:57:01 PM »
Quote
a more beefy power supply

How much beefiness should I be looking for? 2A, more? What did you end up with for sufficient write/erase current from the USB supply?

I would appreciate knowing a good value, so I don't have to reinvent the wheel....

Greg H.

1.8A is recommended for a Pi2.  You can get by with less, though.  It just depends on what other things you have hooked up.

When I was having problems with my original Pi, I was running an old adapter of about 0.5A.  The old wifi adapter I was trying to use was also a major power hog.  It was not a good mix.

This link give more detail: https://www.raspberrypi.org/help/faqs/#powerReqs



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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #9 on: October 03, 2015, 04:49:15 PM »
Thanks.

I am pretty sure that I got the power supply as part of a RPi starter kit. I'll check it the next time I power it down, since I think the current rating is on the 120V plug side and I can't see it right now.

I think that I either got the PS with the RPi as part of a kit, or ordered it at the same time with the PS being recommended.

Greg H.


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Offline dashforecast

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #10 on: February 23, 2021, 01:08:04 PM »
Hi,

I agree that the cost of the industrial SD cards recommended for this purpose can sway the balance on whether this is a cost-effective solution. I'm having a few issues with my weewx disconnecting from the internet every few hours and wonder if the 2GB one I have is too small for the job? It certainly runs into space problems when trying to update packages.

Can anyone highlight if it's just Weewx that has the intensive write activity requiring the durable SD card? If that's the case, has anyone shifted the bulk of the file space onto an external USB? I found this article that explains how to do it https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/msd.md

Thanks in advance for any advice.

Offline galfert

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #11 on: February 23, 2021, 01:24:22 PM »
The use of external USB with a reliable hard drive does not improve your cost perspective compared to SLC SD cards. Also not all "industrial" SD cards are SLC (Single Level Cell). Which means that you should not go by marketing labeling. Sure some "industrial" SD cards are designed a bit better for use in dashcams and such but they are still not at the level of SLC SD cards. The benefit of the USB enclosure with a USB hard drive is performance and the cost for reliable storage compared to SLC SD.

You ask if WeeWX has intensive write activity? Well the question is not whether WeeWX has intensive writing going on but rather the issue is that any Raspberry Pi by nature of the Linux operating system running and doing what it does alone is reason enough to warrant something better than a regular SD card.

If you've been running a Raspberry Pi for a few years on a regular SD card, then I would start to be concerned and plan for some upgrades.

Regardless a regular data backup strategy is essential on any computer system, even if you have reliable storage.
« Last Edit: February 24, 2021, 05:28:16 AM by galfert »
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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #12 on: February 24, 2021, 03:34:25 AM »
The benefit of the USB enclosure with a USB hard drive is performance and the cost for reliable storage compared to SLC SD.

The other significant benefit of an external SSD (say but let's include all external hard drives) on a Pi is availability. It's trivially easy to get a suitable SSD and USB adapter from eg Amazon. The same isn't necessarily true at all for SLC SD cards.

And TBH I don't know offhand exactly what backup solutions are built in to the various Pi station software programs, but I really would like to see an option to easily configure automatic backups to the common cloud storage options like Dropbox, OneDrive, Google Drive etc.
« Last Edit: February 24, 2021, 04:18:37 AM by johnd »
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Offline DaleReid

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #13 on: February 24, 2021, 07:05:18 AM »
Greg, et. al. who have done a card replacement:

If you pull a working card from the Pi and do an image of it with a different computer, I assume you can just plug the new card in and continue along with the life of the new card, or so I hope.  I'm approaching a year on my wx system running WeeWx, and if it fails, I literally would have to start from ground zero.  I'd rather spend a couple days fiddling with new stuff than trying to capture the system the way I have it installed and running now.

Did you find, with your reading, any specific SD cards that are more reliable/robust/better choice than the SanDisk that comes with some of the RaspPi kits?

I'm still hoping to keep the almost invisible profile of a self contained Pi. To hang another powered USB box, with it's wall wart and the external drive seems to add to the clutter.  And an external USB drive as shown in some of the linked articles is a mechanical device, drawing power and I'm not sure designed to spin all day, day in and day out.  So in addition to the pile of electronics and the extra power strip wall wart and all, am not sure if it isn't better to just do SD card swaps, not knowing when one will fail, vs. wasting a card with an unknown time to failure when you plug in the next SD card.

A USB stick seems to be relatively small, not require more power from parts dangling and plugged into their own supply and so on.  Is the memory technology in them able to have many more writes than the SD card technology?

I'd spring for a little SSD but those are SATA based and there seems no provision to hang one onto a Pi

Finally, once the new alternative storage has been selected, is there an easy way to migrate things to the new configuration, or is it better to just bite the bullet and do the time-consuming new install on new storage system/Raspbian set up? 

All very concerning as to the amount of work to get this done with the Achilles heel of the SD card life at the root of all this.
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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #14 on: February 24, 2021, 09:06:21 AM »
I don't have a picture of my Pi 4 with SSD, but here is my old Pi 3B (I keep it as a backup). The SSD is normally stuck to the top of the case with a Velcro pad, it is separate here.

As you can see, no extra power required, and the SSD is smaller than the Pi!


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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #15 on: February 24, 2021, 10:28:45 AM »
The Pi ecosystem is forging ahead. The Argon M.2 case allows an M.2 (SATA) drive to become part of a neat Pi installation. (No NVMe option, but that would be pointless with communication limited to USB3).

https://www.amazon.com/Argon-Raspberry-Support-B-Key-Compatible/dp/B08MJ3CSW7

Granted, the overall price is starting to creep up, but if you're sending $500+ on the weather station then another $100 or so on the Pi package might not be disproportionate.

Or a cheaper if less pretty option might be the TerraPi stand to use with an SATA SSD in a 2.5" case:

https://theterrapi.com/ and https://theterrapi.com/theterrapi/

They also sell a suitable USB3 to SATA adapter accessory.

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Offline DaleReid

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #16 on: February 24, 2021, 12:36:31 PM »
Thanks for the ongoing discussion.

Mcrossley, do you know if the Verbatim SSD has a different technology so that it won't loose it's ability to read/write in a year or so, too?  I assume it does since my Samsung SSD runs 24 hours a day in another computer that has been on for years.  Just checking.

John, you are so right that a few bucks more right now to have a trouble free system for the foreseeable future is worth it.  I am getting less and less enthralled with the 'opportunity' to rebuilt a system when a component fails.  My idea of the Pi is to have it tucked out of sight and out of mind, just doing its job.

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #17 on: February 24, 2021, 12:47:48 PM »
Mcrossley, do you know if the Verbatim SSD has a different technology so that it won't loose it's ability to read/write in a year or so, too?  I assume it does since my Samsung SSD runs 24 hours a day in another computer that has been on for years.  Just checking.
AFAIK its just SSD (probably an M.2 I haven't split one open to find out) and USB adapter in neat package. I can't see them inventing new technology at the price they sell them.

That one had been sat there continuously running my two web sites, MySQL server, and Cumulus MX 24x7 for three years before I retired it to my backup for live server role - I copy across the database and Cumulus data files to it once a day and it has the software installed ready to go. It's still running fine.

The extra capacity of an SSD (that is small one at 128 GB) over the SD card you would normally use means there are more memory locations for the internal wear levelling to work with anyway.
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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #18 on: February 24, 2021, 08:47:27 PM »
That Argon case is sick.

I found some files to print cases too. Dedicated compartments for fan, drive, and Pi. Sort of cool

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #19 on: February 27, 2021, 02:20:36 PM »
I decided to back up my SD card( about 18 months old running 24/7) for my rpi 3B+ using the win imager. Just in case.

All seemed fine. It read the card and generated the backup file. Put back the card in the rpi and fired it up.
Dead. Everything gone. No OS, no weewx. No nothing.

Ok. let's use the backup image.

Nope..just a steady red LED.

Well, now I had an excuse to upgrade weewx to 4.x and install the latest Raspberry pi OS.
Reinstall weewx and all extensions, apps, etc, etc.
Tomorrow will get my Bosch barometric sensor going again.
But now..am beat..
PS. a backup of weewx.conf came in real handy.

PS. tried to upgrade to a better SD card - Samsung Endurance (32GB) pro but no go. That card is just slightly smaller than the Samsung EVO Plus that went bad. Will do post mortem later.
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Offline miraculon

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #20 on: February 27, 2021, 02:55:27 PM »
Greg, et. al. who have done a card replacement:

If you pull a working card from the Pi and do an image of it with a different computer, I assume you can just plug the new card in and continue along with the life of the new card, or so I hope.  I'm approaching a year on my wx system running WeeWx, and if it fails, I literally would have to start from ground zero.  I'd rather spend a couple days fiddling with new stuff than trying to capture the system the way I have it installed and running now.

Did you find, with your reading, any specific SD cards that are more reliable/robust/better choice than the SanDisk that comes with some of the RaspPi kits?

I'm still hoping to keep the almost invisible profile of a self contained Pi. To hang another powered USB box, with it's wall wart and the external drive seems to add to the clutter.  And an external USB drive as shown in some of the linked articles is a mechanical device, drawing power and I'm not sure designed to spin all day, day in and day out.  So in addition to the pile of electronics and the extra power strip wall wart and all, am not sure if it isn't better to just do SD card swaps, not knowing when one will fail, vs. wasting a card with an unknown time to failure when you plug in the next SD card.

A USB stick seems to be relatively small, not require more power from parts dangling and plugged into their own supply and so on.  Is the memory technology in them able to have many more writes than the SD card technology?

I'd spring for a little SSD but those are SATA based and there seems no provision to hang one onto a Pi

Finally, once the new alternative storage has been selected, is there an easy way to migrate things to the new configuration, or is it better to just bite the bullet and do the time-consuming new install on new storage system/Raspbian set up? 

All very concerning as to the amount of work to get this done with the Achilles heel of the SD card life at the root of all this.
Dale

Dale,

Sorry for the delayed response, I have been out of town all this past week.

I used this SD card in my meteohub and so far, so good.

It is a SLC architecture card. I haven't tried a generic RaspPi distribution with a simple clone, but I know that Boris' meteo* architecture doesn't allow cloning for obvious reasons, so I backed up my settings are did a fresh install of the meteohub image. (I know, I know, I should go to meteobridge, etc. but I like my custom plots and scripts)

Greg H.


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Offline WA4OPQ

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #21 on: March 27, 2021, 12:35:43 PM »
Speaking of SD cards.....

I have three layers of SD card "quality" in use

I have converted one of my meteobridge installs to a pi, which requires a SLC card
I found 2GB SLC on eBay for $5 each.

I have several remote stations, each about 30 minutes from my home.
On those I use Sandisk Industrial cards. Not SLC but a grade above consumer products, and just a few dollars more.
https://www.amazon.com/gp/product/B085GLQB78

Then for any pi I use at my home I use Sandisk Ultra
« Last Edit: March 27, 2021, 12:38:05 PM by WA4OPQ »

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #22 on: March 27, 2021, 12:38:06 PM »
I found 2GB SLC on eBay for $5 each.

And you believe that?!?!
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Offline egeezer

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Re: SD card flash life on Wx programs using Raspberry Pi
« Reply #24 on: April 03, 2021, 04:22:53 PM »
You might even want to try using an SSD, which would do well in applications requiring lots of R/W activity.

Here's an article on 'how to' and performance from Toms Hardware;
 https://www.tomshardware.com/news/raspberry-pi-4-ssd-test,39811.html
It also links to an article on how to enable boot from SSD. I'd suggest reading it fully before selecting a drive.

SSDs have come down in price since the article was posted. I looked briefly and found external drives at Micro Center for as little as $40. A SATA SSD drive with a USB case might also be an option. Just be sure to verify compatibility. 
 See https://www.microcenter.com/search/search_results.aspx?N=4294822457+4294966998&NTT=External+SSD&NTK=all&sortby=pricelow

 

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