Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi. > if I check the status of drbd the following response is: > > 0: cs: Connected ro: Primary / Primary ds: UpToDate / UpToDate C r ---- > ns: 640864680 nr: 135234784 dw: 776099464 dr: 1520599328 al: 836478 bm: > 2185 lo: 0 pe: 0 ua: 0 ap: 0 ep: 1 wo: b OOS: 0 > > I do not know if it is positive that the method is to write after is Barrier > .... reading the manuals of drbd I noticed that in these cases (BBU) > performance would be better for a wo:n > > What do you think? Possibly? You may want to just test the performance difference. > more to this I can tell you that another hardware configuration with a > simple SATA disks in software raid 0 configuration (sda and sdb) and > without drbd.conf options: no-disk-flushes -no-md-flushes, The drbd uses > instead the drain ... that seems to be dangerous without a BBU, but the drbd > has preferred this choice, and not clear to me ... Check you kernel logs. DRBD may have noticed that barriers are not available for your backing device and thus falls back to drain. Is LVM involved in your that setup per chance? Regards, Felix