USB Storage Full Question

[HAL2001]

How many times we gonna debunk this one?

The car simply does not write that much.

The "dedicated camera recording heavy duty" stuff is expecting to be recording multiple 4k 60 fps video streams.

The car records 30 fps at 720.

720p at 30 FPS isn’t that bad depending on the codec. but you have to consider there ar 4 cameras writing at the same time. Plus the writing that goes on to manage the loop recordings on each Camera.

Each camera records about 25 mb per minute. That’s 100 mb per minute total or 6 GB per hour. A cheap stick can do about 10,000 write cycles a good stick can do 100,000 cycles. if your formated for 512 byte sectors, 1 minute of video will do 50 writes, times 4 cameras that is 200 writes. So now it’s jus a matter of how often it reuses the same area on the stick and how good the stick is. 200 writes a minute can hit the rated write cycles In a year or two easily. A average usb stick can reach it’s rated cycles within a year of normal driving. A better rated stick will last longer. An SSD is rated for 200-600 terabytes of writes so an SSD is your better option for longevity.

But an SSD uses more power than a stick and if you let too many video files build up on a big drive the viewer will slow way down so it’s best to limit your usage to less than 200 GB. My SSD is partitioned 250 GB for sentry and the rest for music.

IMHO only the high write rated usb sticks will last more than a year or two. If it’s counterfeit then way less. And the number of counterfeit sticks sold on eBay and Amazon is amazing. There are not many counterfeit SSD drives.

 

[Knightshade]

720p at 30 FPS isn’t that bad depending on the codec. but you have to consider there ar 4 cameras writing at the same time. Plus the writing that goes on to manage the loop recordings on each Camera.

Each camera records about 25 mb per minute. That’s 100 mb per minute total or 6 GB per hour. A cheap stick can do about 10,000 write cycles a good stick can do 100,000 cycles. if your formated for 512 byte sectors, 1 minute of video will do 50 writes, times 4 cameras that is 200 writes.

That's... not generally how that's measured...

1 write cycle is the entire capacity of the drive can be written to once- you don't use up a write cycle for each sector you write

Understanding Life Expectancy of Flash Storage for LabVIEW Real-Time Systems

This document discusses how several factors impact the Drive Endurance formula when used to calculate how much data can be written to a drive before it becomes unreliable. Selecting the right flash-based storage device for your application often demands a tradeoff between cost, capacity, and...

www.ni.com

Drive Writes (DW): The number of times a drive can be filled before it becomes unreliable

A 128GB stick can have 128GB written to it (slightly less when formatted, but not enough to change the math much)... and that's one write- not hundreds.



If we assumed 6GB per hour (it was higher last time I looked but maybe they've switched to a more efficient codec) on a 128GB key that's going to use one cycle after 21.3 hours.

For typical use (where you don't have sentry running at home- just to/from the house, and parked at work or stores) that's roughly 1 cycle every 2 days... (it's probably less than that on average, but let's use that to be safe).

Meaning in 1 year (365 days) you'd use 182.5 cycles.

So even a 1000 cycle lifespan means your drive is good for about 5.5 years.

3000 cycles (the higher end of good TLC flash, which is most common in quality flash drives) gets you over 15 years.

Switch to a 256GB key and now you're looking at 11 years with only 1000 cycles, and over 30 years at 3000 cycles.

 

[HAL2001]

That description of a write cycle is just for ease of user understanding. Write the same sector of the stick 10,000 times and you will have reached the rated limit of that sector. As files are deleted for loop recording the space is marked for reuse. most operating systems use the first available space so the start of a drive is the most written to.

it does not require the drive to be filled 10,000 times. You only need to exceed the rated writes to any part of a stick.

 

[Knightshade]

That description of a write cycle is just for ease of user understanding.

Can you cite a technical source supporting your own version of the definition instead of the one I provided?

Write the same sector of the stick 10,000 times and you will have reached the rated limit of that sector.

But that's not how the drive is actually written to.... so... what are you talking about?


In fact you'd have to actually go out of your way to intentionally write like that since the filesystem (and hardware) is generally actively working to prevent you doing that.

As files are deleted for loop recording the space is marked for reuse. most operating systems use the first available space so the start of a drive is the most written to.

You understand OSes have treated flash storage differently than regular storage for longer than Tesla has been mass producing cars right? And that even USB keys themselves, years ago, added controllers than also addressed these issues?

It's called wear leveling.

So no it will not just write to "the start of the drive"

Your information appears to be some combination of badly dated info and/ or applying mechanical HDD concepts to flash storage when they don't really apply.

 

[diamond.g]

USB sticks come with wear leveling now (I presume that means TRIM support)? I know SSD’s tend to, but I didn’t think that extended to USB sticks.

 

[ODWms]

If this helps, this is the setup I‘ve used since day one (over 2 years), with zero issues:

https://imgur.com/a/bNGbJ9v

 

[Knightshade]

USB sticks come with wear leveling now (I presume that means TRIM support)? I know SSD’s tend to, but I didn’t think that extended to USB sticks.

USB sticks have had wear leveling for many years.

https://forum.corsair.com/forums/showthread.php?t=79201

That's a forum thread from 2009- 3 years before the Model S even came out- debating which type of wear leveling different models of that brands USB sticks used.

I suppose it's POSSIBLE someone in recent years stills makes an absolutely garbage one they give out free at conventions without it, but any name brand that shouldn't be the case and hasn't for a long time.

 

[HAL2001]

The Tesla sticks are formatted in exFat which is not a wear level OS format. So the stick will need to have a wear level controller. However most consumer level USB sticks do not have wear leveling in the hardware so you fall back to the OS. Although I cannot specifically speak for Tesla’s OS, most OS’s in exFat format go for the first contiguous space available that will fit the write. So it will likely write to the same area of the stick over and over as files are deleted for looping. That will potentially cause a stick failure once the rated write limit is exceeded.

IMHO, unless it’s a performance rated USB stick it has a average life span of 2 years. Which back to my original point is why an SSD is better for longevity because they all include a higher write threshold which is due to the fact that SSD’s utilize static wear leveling.

 

[Knightshade]

The Tesla sticks are formatted in exFat which is not a wear level OS format.

If you mean the ones Tesla now includes with new cars, can't say as I've had mine since well before they began doing it.

But there's no reason you have to keep using exfat if you don't want to.

https://www.tesla.com/sites/default/files/model_3_owners_manual_north_america_en.pdf

Model 3 requires the drive be formatted as exFAT, FAT 32, MS-DOS FAT, ext3, or ext4

This is largely irrelevant though because, again, you appear to be relying on a factually wrong understanding of flash storage and capabilities-

So the stick will need to have a wear level controller. However most consumer level USB sticks do not have wear leveling in the hardware so you fall back to the OS

This is absolutely false.

I even posted a link to a thread from 2009 discussing consumer USB sticks having wear leveling onboard via their controllers.

. Although I cannot specifically speak for Tesla’s OS, most OS’s in exFat format go for the first contiguous space available that will fit the write. So it will likely write to the same area of the stick over and over as files are deleted for looping. That will potentially cause a stick failure once the rated write limit is exceeded.

It certainly will not do that, though the OS might "think" it's doing that.

Because what the controller presents to the OS is completely different from what it's doing putting data on the flash storage.

Is it possible to wear-level a FAT32 file system?

Because SD cards use flash memory, they should requires wear leveling to avoid significantly shortening the life of the card. At the same time, my understanding is that they usually use a FAT32 file

cs.stackexchange.com

That's a thread where someone is asking about wear leveling if they are running FAT32.

Several replies point out the question misunderstands how any of this works- as you appear to be doing.

For example:

The OS references blocks using a "logical block address". The SD card then maps this to a physical page of flash memory. With wear leveling, each time data in that block is changed, it will get mapped to a new physical page of flash memory. So, even though the OS is changing the same "logical block address" every time, this is causing different physical pages in flash to be erased and rewritten. This spreads out the "wear" across the entire flash device, lengthening its lifetime and avoiding the problem you mentioned. In other words, although the FAT32 is stored at the same "logical block address", it isn't stored on the same physical page of flash memory every time it is modified.

IMHO, unless it’s a performance rated USB stick it has a average life span of 2 years. Which back to my original point is why an SSD is better for longevity because they all include a higher write threshold which is due to the fact that SSD’s utilize static wear leveling.

USB sticks also utilize wear leveling.


SSDs last longer because of 3 reasons-

1) They generally are much larger, so using 1 full write cycle (which again is writing the ENTIRE CAPACITY of the drive, not just 1 block) takes a lot longer.

and

2) They tend to use higher-end types of flash rated for more cycles (though this is not as true as it used to be outside of VERY expensive enterprise applications)

and

3) With usually larger physical size and higher pricing they can also overprovision (include more "spare" flash) on the physical device.



All that said- again, run the math properly and you're going to get 5-10 years in typical use out of a quality 128GB stick for the little that the Tesla writes to it.


But if you desperately need to save dashcam footage for your grandkids- then spend a few extra bucks not on an SSD- but on a large max-endurance SDCard.

It will use a lot less power, stand up to a lot wider range of temperatures, take up less space, and last decades.


The only reason to seriously consider an SSD in the car is if you need a TON (like 512GB and higher) room for music because SDcards and USB sticks tend to escalate a ton in price at that point versus SSDs.... (and of course since 95% of your use there is READING, not writing, you're STILL not benefiting from higher write endurance- you're just getting more space for an affordable price).[/B][/QUOTE]

 

[ianc]

Or if you don't want to wait an AGE for the drive to rescan every time you add music to it. My WD 500 GB nvme drive scans in about 1/3 the time my old 256 GB flash drive did, not to mention that copying large amounts of data to it from my computer is MUCH faster...

 

[Knightshade]

Are you changing the music drive contents and thus removing/reinserting it a lot?

I don't notice rescanning to be an issue on my 256GB music stick, but I also don't remove the drive and change its content more than a few times a year.

(nor would the speed really matter other than the very first time you load to the key, unless you're replacing MASSIVE amounts of music frequently- in which case you're gonna want an SSD simply because it means you've got too much music in your collection to reasonably/affordably fit on a single stick anyway)

 

[ianc]

Yeah, I'm ripping\adding music to the drive all the time and it's a PITA. With the 256 GB flash drive, I could drive to the grocery store and and it wouldn't finish until halfway back!

 

[Gauss Guzzler]

What @Knightshade said.

And also not what @Knightshade said. There's no science needed here. Just shove a $10 USB stick in there, replace it someday with a $1 stick, and again with a $0.10 stick. That'll get you thru the first 100 years, how long do you really plan to keep the car?

But the OP wasn't asking about file systems, they were asking about software bugs. Have there been any rumors about this getting fixed? I assume Tesla probably didn't intend to invent the world's first non-looping security camera system.

 

[Knightshade]

But the OP wasn't asking about file systems, they were asking about software bugs. Have there been any rumors about this getting fixed? I assume Tesla probably didn't intend to invent the world's first non-looping security camera system.

But it IS a looping system.

It will always overwrite the previous 60 minutes, every time you start a new drive (or if your drive runs over 60 minutes).

It will secondarily overwrite the oldest sentry files if it's running low on space there too- but it does that as a secondary step because it might be days or weeks before you even realize you NEED a sentry clip... (for example many folks never even look at the passenger side of their vehicle for days or weeks if they have no passenger- but then might notice a ding and want the footage of what happened).

The only files it will not automatically overwrite, rather than stop writing, are the ones the user who explicitly marked to be SAVED (as in NOT overwritten).

This is largely explained around page 74 of the owners manual, and already discussed in reply to the OP.


Since flash memory tends to slow as it fills, best practice would be for you to clear out the sentry folder every so often such that it never gets to that point of giving you the message.... likewise if you routinely SAVE (ie manual save that does not get automatically overwritten) a LOT of footage, you should routinely copy that off the cars drive as well.


The nearest thing to a bug you could attribute, and it's not a bug just a design choice, is how "near" to full the drive gets before the car throws that message out.

I want to say I recall that originally when they added the code that will auto-overwrite sentry (which it ORIGINALLY did not do- but has for quite a while now) it was set to only overwrite if the drive was 95% full. Which seemed high to me at the time.

I'd have gone with 80 or 85%, given performance hits usually start getting significant at 90% full.



Oh- and while we're improving existing features- on the format menu, I'd love an option to ONLY clear the "sentry" folder, or ONLY clear the "saved" folder, rather than a full drive format... though given how often we see folks who don't understand the different folders I expect that would confuse a lot of owners.

 

[HAL2001]

This is absolutely false.

I even posted a link to a thread from 2009 discussing consumer USB sticks having wear leveling onboard via their controllers.

IMHO Only the high end Professional flash drives have built in wear leveling. Most stuff sold on eBay and Amazon does not appear to have the on board controlder.

tesla had issues with flash memory in the MCUv1 early on. I recall seeing a YouTube video about the flash storage on the Tesla computer failing due to the OS logs being written constantly.

I still feel an SSD is a better solution or at least use a pro level usb flash drive. Probably something with an endurance rating. Unless your lucky, the consumer stuff will get you a year or two.

 

[TraumaDoc]

How many times we gonna debunk this one?

The car simply does not write that much.

The "dedicated camera recording heavy duty" stuff is expecting to be recording multiple 4k 60 fps video streams.

The car records 30 fps at 720.

Any decent flash memory ought to be good for 5-10 years with average use and its normal rated life.



Sure- if you get a fake samsung with who knows what in it you might have issues.

But it's not like there's not cheap/fake SSDs out there too.

Buy a reputable product from a reputable vendor- and there's various tools out there to help you check the product when it arrives by all means use one. but putting the drive into use in the car.

I've had two sandisk fit USB drives each fail within a fortnight of constant sentry mode.

My Sandisk endurance micro SD in a USB adapter has now lasted over a year.

N=3, but you'll find this is not a unique story.

 

[Knightshade]

I've had two sandisk fit USB drives each fail within a fortnight of constant sentry mode.

My Sandisk endurance micro SD in a USB adapter has now lasted over a year.

N=3, but you'll find this is not a unique story.

You got counterfit or defective drives.

There is zero chance you'd have worn out a non-defective name brand flash drive in two weeks

Even if it was an 8GB drive (which is like 8 times smaller than the smallest the owners manual recommends) you'd only burn through around 300 cycles in 2 weeks.

A 64GB drive (which IS the smallest they suggest) would only burn through about 40 cycles.... and that assumes it's running 24/7 and your car never sleeps.

IMHO Only the high end Professional flash drives have built in wear leveling.

Then your opinion is factually wrong.

I posted a source from -12 years ago- mentioning wear leveling built is was already common then on USB drives.

There's tons more threads from years ago discussing all the major stick makers offering it too.

Most reuse the same few controllers among them (many from phison)- and the controller is where the wear leveling is implemented.

Some examples-

Wear Leveling - Transcend Information, Inc.

Wear Leveling is used almost universally in Flash products today to ensure that data is written equally to...

www.transcend-info.com

Transcend’s Flash product lineup supports Wear Leveling to ensure product endurance and reliability.

Not "only our SSDs" but their entire flash product lineup.

Does my USB Flash Drive have wear leveling?

Thanks!

forums.sandisk.com

all the flash drives have the wear levelling algorithm inside that prevents the data to be written to the same blocks all the time.

Any "Fit Size" USB Flash drives with static wear leveling?

Here are some that I am looking at: https://www.samsung.com/us/computing/memory-storage/usb-flash-drives/usb-3-0-flash-drive-fit-32gb-muf-32bb-muf-32bb-am/ https://www.sandisk.com/home/usb-flash/ultra-fit-usb http://www.pny.com/elite-x-fit-usb-3-0-flash-drive EDIT...

forums.anandtech.com

One post links to the Phison and Silicon motion controllers most often used on USB sticks by many companies, with all of them supporting wear leveling (this is from 2017 BTW)
Another post mentions have directly gotten confirmation from both Samsung and Lexar support that all theirs had wear leveling.

Most stuff sold on eBay and Amazon does not appear to have the on board controlder.

No controller at all?

How does it work then- since it's clearly not the OS directly controlling raw flash.

None of this works the way you imagine it does.

tesla had issues with flash memory in the MCUv1 early on.

Yes.

That was 8 MB of flash.

And generally failing in 5-8 years on average.

You're in here telling us how 128GB sticks will fail in a year.... (of course it's entirely different types, and amounts, of writing so it's kinda weird to even bring up....)

 

[TraumaDoc]

You know what they say about assumptions....

both drives were 64gb, bought from a major high street national supermarket, so I'd say the chances of them being counterfit are zero.

both had worked flawlessly in low demand situations for a year - occaisional file transfers and not pysically abused.

You assume write cycles is the only reason for failure, where vibration, temperature, data throughput on the controller may all play a factor

 

[Knightshade]

You know what they say about assumptions....

both drives were 64gb, bought from a major high street national supermarket, so I'd say the chances of them being counterfit are zero.

both had worked flawlessly in low demand situations for a year - occaisional file transfers and not pysically abused.

You assume write cycles is the only reason for failure, where vibration, temperature, data throughput on the controller may all play a factor

Temp and vibration COULD be factors.

But there's USB sticks out there rated similarly on those factors as SDcards (and generally both are much better rated for those then SSDs)

For example Sandisk lists their FIT USB drive as having an operating range of 32-95F and storage range of 14-158F

Sandisks High Endurance SDcard lists as having an operating range of -13 to 185F and storage of -40-185F

So for Sandisk there's a significant difference (though either would be fine if you keep cabin overheat protection on).

Samsung OTOH specs their FIT Plus USB stick (the drive I personally recommend, and the one Tesla does as well in the owners manual) as -13 to 185F operating and -40-185F storage... so exactly the same as the endurance SDCard from Sandisk.

Samsung also specifies theirs as vibration-proof, while Sandisk does not.

 

[Jason Z]

It will also probably fail at some point, I never had one last more than a few months. Recommend getting an SSD drive, works so much better.

Just buy those USB drive with a hefty full size metal body, and not those mini ones. It does get hot due to constantly writing large amount of data to disk, and needs the surface area to dissipate heat. Plastic body traps the heat and fries the electronics in the USB drive.

The reason SSD don't fail as easily is because they are much bigger and has the large surface area to dissipate heat. I have had a metal body USB drive in the car for over 3 years now, still working good.