Mine aren't missing a 0, I divided wrong and added a 0, so I am using 5MB and 3MB, which would leave my spread at 2MB or at say 100MB/sec 1/50sec. It has been a long time since I set them and my system works decent during copying. On Tue, Mar 31, 2020 at 7:22 PM Samuel Sieb <samuel@xxxxxxxx> wrote: > > On 3/31/20 5:00 PM, Roger Heflin wrote: > > These are what I set: > > vm.dirty_background_bytes = 3000000 > > vm.dirty_bytes = 5000000 > > I think you're missing a zero. If those are your actual numbers, you > have a very small buffer. Even with your numbers that seems a little small. > I have noticed that copy big files especially over USB bogs the system > pretty badly. I'll try modifying my settings to see if it helps. > > > That limits the to-be-written bytes to 50Mb, and when it hits 50MB it > > will clear the write cache down to 30MB and let writes happen again. > > Since 20MB of writes happens pretty fast on modern HD's this makes > > response reasonable. If these 2 values are 0 then these 2 rule: > > vm.dirty_background_ratio = 0 > > vm.dirty_ratio = 0 > > You can only set one or the other. Setting the bytes resets the ratio > and vice versa. > > > You might note what the default is, all my system have it overridden. > > /proc/sys/vm/dirty_background_ratio: 10 > /proc/sys/vm/dirty_ratio: 20 > > Here's the info on those settings from the kernel doc: > https://www.kernel.org/doc/Documentation/sysctl/vm.txt > ============================================================== > > dirty_background_bytes > > Contains the amount of dirty memory at which the background kernel > flusher threads will start writeback. > > Note: dirty_background_bytes is the counterpart of > dirty_background_ratio. Only > one of them may be specified at a time. When one sysctl is written it is > immediately taken into account to evaluate the dirty memory limits and the > other appears as 0 when read. > > ============================================================== > > dirty_background_ratio > > Contains, as a percentage of total available memory that contains free pages > and reclaimable pages, the number of pages at which the background kernel > flusher threads will start writing out dirty data. > > The total available memory is not equal to total system memory. > > ============================================================== > > dirty_bytes > > Contains the amount of dirty memory at which a process generating disk > writes > will itself start writeback. > > Note: dirty_bytes is the counterpart of dirty_ratio. Only one of them may be > specified at a time. When one sysctl is written it is immediately taken into > account to evaluate the dirty memory limits and the other appears as 0 when > read. > > Note: the minimum value allowed for dirty_bytes is two pages (in bytes); any > value lower than this limit will be ignored and the old configuration > will be > retained. > > ============================================================== > > dirty_ratio > > Contains, as a percentage of total available memory that contains free pages > and reclaimable pages, the number of pages at which a process which is > generating disk writes will itself start writing out dirty data. > > The total available memory is not equal to total system memory. > > ============================================================== > _______________________________________________ > users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx > To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx
