Timeline for How to reduce Linux' write buffer for removable devices?
Current License: CC BY-SA 3.0
7 events
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| Aug 20, 2022 at 10:22 | comment | added | Mikko Rantalainen | See also: unix.stackexchange.com/q/714267/20336 | |
| Aug 18, 2022 at 6:46 | comment | added | Mikko Rantalainen |
After using low dirty_bytes setting (200 MB) for a longer time, I've noticed that using single global limit is pretty bad because slow device can still fill the buffer and then writes to another fast SSD device suffers as a result. The correct fix is to apply device specific limit but there doesn't seem to be a simple way to do that. I think optimal setting would be 200 MB per device for my case.
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| Aug 28, 2020 at 1:35 | comment | added | rsaxvc | Decreasing the write_buffer size below the current utilization may lead to a somewhat unresponsive system, as it appears new writes are blocked until space is available in the cache, which is now overfull. Creating a directory in this state has left me enough time to clean up a kid's toys in the yard, cut a slice of key lime cheesecake and a glass of milk, and finish both while I write this from my phone. | |
| Apr 9, 2020 at 18:27 | comment | added | pipe | This isn't the complete answer to your original question though. I want to throttle my external slow storage, not my internal fast storage... | |
| May 17, 2017 at 7:18 | comment | added | Mikko Rantalainen |
Both 32-bit and 64-bit Linux kernels use default dirty_ratio of 20. However, 32-bit kernel has maximum available kernel RAM limit of 1 GB due to limits of 32-bit x86 architecture. As a result, maximum default write cache size on 32-bit system is around 180-200 MB depending on hardware (at least PCI devices with DMA access will reduce usable RAM limit).
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| Jul 2, 2016 at 19:40 | vote | accept | 1N4001 | ||
| Jul 2, 2016 at 19:38 | history | answered | 1N4001 | CC BY-SA 3.0 |