USB Write Speed Too Slow = Drive Full

USB Write Speed Too Slow = Drive Full

Again today, for the fourth time, I have gotten the dreaded "USB Write speed" error (twice on each car over past few months). Thing is, the USBs are 128GB / 300 mbps usb 3.1 flash drives so, no, they are plenty fast. Each time I have removed the drive, cleared out the saved sentry videos, and plugged them back. Each time they have started working fine again for another few months.

Word to the wise: if you get the read/write speed error, try to clear the videos or reformat before you run out and buy another drive.

gmr6415 | 2019年10月18日

@TexasBob, you can save yourself some time by just doing the scroll wheel reboot with the USB drive still plugged into the car.

It always worked for me. No need to pull out the drive, clear the videos or reformat.

I will say though that I recently went to a 500GB G Drive (SSD) with one partition for dash cam, one for music and one for audio books, and I haven't had the error since.

andy.connor.e | 2019年10月18日

You probably bought one of those USB drives that has a 300mbps READ speed, and 20MBps write speed. You need write speed to be high.

TexasBob | 2019年10月18日

@gmr6415 - I tried the reboot first time and it did not do any good. I may try again first in ~ Jan when this happens again...
I think the G Drive is a great idea. I do not make use of other media enough to justify the extra storage, but for people who want to keep the music/book library, I think yours is an excellent solution.

@Andy.connor.e - no, I bought a samsung with a 300 mbps read / 60 mbps write which is in line with the TeslaTap recommendations (below for anyone looking for recommendations). I get several sentry alerts each day in the parking garage, so that may be what is filling the drives.

In any case, just wanted to offer this suggestion for folks before they go out and buy another drive.

andy.connor.e | 2019年10月18日

Im confused. Are you having transfer speed issues, or is your drive actually filling up?

TexasBob | 2019年10月18日

Hi Andy, the drive appears to be filling up but it is giving me the write speed error. Apologies if I was unclear. What I was trying to say is that it seems as though the car will sometimes give a "write speed" error when all that is actually wrong is that the drive is full. Or it may be that as the drive gets full it starts writing more slowly. In either case, clearing the drive of old videos solves the problem.

andy.connor.e | 2019年10月18日

i see now.

Rodo | 2019年10月18日

Software v10 is supposed to overwrite the sentry events if they're taking up more than 5GB. I haven't tested this feature though. I hardly use sentry mode. The USB flash drive may be getting old. Have you tried the microSD cards instead? BTW USB v3 is nice but useless in a Tesla USB v2.

james.phil | 2019年10月18日

This started happening to me today. My USB stick is also a 128GB Samsung with 300mbps read speed and 60mbps write speed. Is it something to do the recent software update? I've just reformatted it and put it back in. Failed virtually straight away.

Hp.1193 | 2019年10月18日

It’s something in V10. I have the same issue. Before, the drive worked flawlessly for 6 months.

a1chang1 | 2019年10月18日

I recently just got V10, so far I have not had any errors on my "Samsung MUF-128AB/AM FIT Plus 128GB - 300MB/s USB 3.1 Flash Drive" . I have Sentry on and the stick is broken up with 2 partitions, one for DashCam and the other for music. Also, I am no where close to full in either partitions, especially the DashCam.

Like James above states, this unit has about 300 MB/s read and 60 MB/s write.

There are quite a number of sticks with OK read speeds but terrible write speed. I start to develop errors on V10, I will separate the dashcam from the music.

BlueHour | 2019年10月18日

After updating to v10 I got it several times. Two finger salute always cleared the problem, but today I decided to pull the drive (Samsung usb) and check the recordings. The partition (I have two, another one with music ) was full, filled with Sentry recordings from my garage, overnight, in the darkness. I don't think I enabled sentry on purpose.

a1chang1 | 2019年10月18日

Hmm. curious, do you format the partition to erase it, or manually delete all the files? Maybe some where along the way the partition is corrupt? In the old days, it paid to do a low level format to speed up the write speed instead of deleting alot of files..I don't hear folks saying that they do that any more. A real SSD drive performs this erasing of delete files space in the background. (Aka Trim.)

Maybe the next time it happens, try running a speed test on the USB stick before and after the error or reformatting the stick.

Why is Sentry recording your garage in the dark? I thought is was supposed to only record when it detect movement? Is that "new" with V10 in a bad way. I have Sentry on except when home.

I just pulled my stick. It does record for a certain amount of time from when I first pull in in recent, but older files were purged. I don't have more than today's in recent. The other directory, "Saved" and "Sentry" are only a few files which are saved since I got V10 recently.

I also might be pulling out the stick at the wrong time since there is an error when I install it in a PC and it asks to scan and fix it.

RedShift | 2019年10月18日

Here is my concern. It’s a ‘bug’ that makes the drive fill up with these non-event sentry mode videos. I know, because I have turned the sentry mode off, and yet I keep getting the videos filling up my drive even when the car is parked in the garage with no one around!

Why cannot Tesla fix that bug? Too busy with fart noises again?


Hp.1193 | 2019年10月18日

More info link:

Overheating issues and “upping” requirements when they added rear cam.

Might try the micro SD route.

Tronguy | 2019年10月18日

And.. Just to add fun to the fire. The way most FLASH memory (that includes USB sticks) works, there's this issue about wear-out. All FLASH storage has a limited number of write cycles, beyond which they stop working. Depending upon the quality of the FLASH, this can be a couple of thousand to a couple of hundred thousand write cycles.
So, in an effort to keep FLASH drives alive, they're 1) divided into blocks of a few thousand bytes, 2) the FLASH controller keeps track of the number of write cycles, and 3) there are usually a number of spare blocks. When a particular block gets used One Too Many Times as compared to other blocks, the FLASH controller will copy the data in that block into a spare and remap the spare into the pile of blocks under current use. As time moveth on, even blocks in current use with low write cycle counts will have contents swapped with a block that's got a high cycle count, the eventual idea being that it'll take a good long time before the overall drive reaches an even wear-out limit.
So, there's room for variation on this scheme. For example, if one is writing along, and the algorithm running in the FLASH controller decides that it's time for a block swap, that _just_ _happens_, no matter what else is going on.
Now, my suspicion is that the better grade of USB drive has a bunch of RAM blocks that it uses to handle on-going write requests while it swaps blocks in the background, so the advertised write speed is right up there with the read speeds. However, I'll lay bets that the cheaper quality devices probably chug along at a goodly rate of speed right up until a block swap has to be done; and that's when that slow write speed shows up while blocks are swapped.
So, you've got a USB drive that's working fine for a month or three and then start saving more and more data.. That's when I would expect that block swaps would rear their ugly heads and slow the drive down. Intermittently.
Isn't electronics fun?

Tronguy | 2019年10月18日

And, yeah, this block-swapping characteristic of FLASH is one of the reasons that applying wipe software to solid-state drives isn't guaranteed to clear the drive - all those used blocks with data hanging out in the spare block store. You'd need the drive manufacturer's special debug software to wipe those blocks, assuming that the capability to do so is actually enabled.
(By the by: All of the above is spoken by a person who has actually had to contend with no-kidding wear-out problems in an industrial setting. With some drives, it's possible to dump the sector write cycle count data.)

Hp.1193 | 2019年10月18日

Sorry, but that’s not the issue in this case.

Next time be sure to provide a short, simple summary of your Addy-fied content plz n thx :)

james.phil | 2019年10月19日

Hmm, I'm now trying the SSD card route with a USB adaptor as suggested by a forum thread from Tesla Motor Club. My wife has Apeman camera in her car and that uses an SSD card.

birchofengland | 2019年10月19日

FWIW, I often had the write speed issue flag using several different flash drives and cards. I now have a SanDisk High Endurance Video Monitoring SD Card 64GB (SDSDQQ-064G-G46A), which has had no issues at all. I don't need a bigger capacity card for my style of driving as it's mainly used for the dash cam rather than Sentry mode.