> I have done additional research, and it now appears that programs that do > extensive disk writes run much slower (3-6x) in Bookworm than they did in > Bullseye. The two cases I have observed are 'svnadmin dump', and extracting > an SQL backup of a Bacula database from Postgresql (backup file about 3 GB). > Operations that perform extensive reads (a Bacula backup operation to > magnetic tape, 600 GB) seem to run at the same speed as before. > > At the moment, this is a 32-bit PAE system. I don't know of an obvious > reason why that would matter. At the time of the upgrade, the system memory > was enlarged from 16 to 32GB, in anticipation of converting the system from > i386 to amd64.
FWIW, I've had very serious write performance issues on my Thinkpad T61 (8GB RAM + SSD) when using a 32bit PAE kernel (occasionally below 1MB/s, tho not reliably reproducible, e.g. not right after boot). Those problems disappeared when I switched to an amd64 kernel (while keeping the userland 32bit). https://serverfault.com/questions/996495/writes-throttled-to-500kb-s Your symptoms seem quite different, but with 16GB of RAN, I'd strongly suggest you try an amd64 kernel, just in case. Stefan
