Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Dec 30, 2009, at 3:27 AM, Lars Ellenberg wrote: > On Tue, Dec 29, 2009 at 03:56:17PM -0700, Josh Aune wrote: >> Hi, >> >> Attached is a patch for the users guide. > > Thanks. > >> Also, I'm having an issue with sync performance. I have DRBD setup >> between two hosts using SRP. > > SDP maybe? Ya, that one :) > >> Under optimal conditions I'm able to achieve a 500+ MB/s write speed, > > How do you measure? $ iostat -m 1 On both hosts while running a benchmark. On the host with the benchmark I see 500+ MB/s register on both the drbd1 and fioa devices, on the remote host it registers 500 MB/s on only the fioa device. While running the initial sync both sides register between 50-80 MB/s reads, no writes. Doing a local benchmark using 4 processes of 32k reads this device can easily sustain 600+ MB/s. >> but during the initial sync after the DRBD device is created the sync >> proceeds at less than 100 MB/s. Below is the config file. Am I >> missing anything needed to bump up the initial sync speed? >> >> Also, all bytes on the drives on both side are zeros, so the limitation seems to be in the crc32c processing. > > Did you look at top, vmstat or similar? Yes, 87% cpu idle. Nothing much really happening. Thanks, Josh