[DESKTOP] How to disable write Cache in 18.04 LTS

[HWDude37]

All,

My system is running 4.15.0-29-generic #31-Ubuntu SMP Tue Jul 17 15:39:52 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux with all updates applied as of the time of this post.

I've searched on "disable write cache" and got no results. Tried other combinations and got non-related or confusing results. Not sure what the correct keyword search should be to find this...

I am writing a 1.6GB image file to a 32GB class 10 uSD card (in a USB adapter) and it thinks it's done in < 1 sec. The GKRELL system monitor shows write activity to the USB drive for at lease 5 minutes afterward, and the adapters indicator light is flashing the entire time. The command line prompt returns immediately - I want it to only return when the write to the USB uSD card is actually finished.

I am writing to /dev/sda

I would like to disable the write cache feature (preferably to ALL drives), but have no idea where to look for this setting. Can't seem to find it in the system settings menu.

HELP!

Boiler plate info:

MB: MSI Bazooka B350M, 3.6 GHz AMD RYZEN-7 CPU with 8 dual cores, 32GB DDR4 memory, 500GB M.2 SSD, NVIDIA GEFORCE GTX 1060 video card, 2 x 27" ASUS monitors

Any useful help would be appreciated!

HWDude37

[GreyGeek]

It could be ballo and/or akonadi indexing your files.
akonadictl status
will list the directories being indexed. Is one of them on that USB stick?
balooctl disable
will turn off baloo indexing.

[jlittle]

... it thinks it's done in < 1 sec...

I don't have a solution atm, sorry...

It doesn't think it's done, rather the write is handed over to to an i/o slave. You're supposed to get a notification later when "it thinks it's done". So it's not write caching you're up against; if it was, a sync would wait for the the cache to be flushed, and an eject does a sync.

You should be able to find a progress bar in KDE somewhere showing the copy.

Regards, John Little