https://bugzilla.kernel.org/show_bug.cgi?id=201331 --- Comment #10 from edo (edo.rus@xxxxxxxxx) --- > A substripe write will require 4MiB + parity (which IIRC will be another 1024MiB) so a total of 5MiB needs to be Read, modified and written for each undersized write. I'm pretty sure, md raid can do partial update for chunks. I just ran 4Kib random write test (fio) on freshly created array with chunk size 4Kib, after that with chunk size 16Mib - no difference in terms iops on raid device (observed in fio), iops and transfer speed on raid members (observed in iostat). > Your system is not locked up, it's just really slow due the amount of time being spent waiting for IO completion. No. Array was filling with good speed (80-250Mib/s, limited by network) several hours after system startup. Unexpectedly write stopped (zeros in iostat) and messages "blocked for more than 120 seconds" arrive. I managed to continue disk filling with hardware reset only. Such behavior repeated many times, I tried several kernel versions and kernel options. -- You are receiving this mail because: You are watching the assignee of the bug.
