Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Greetings, I'm doing some experimentation with DRBD and relatively low speed links (~30Mbps), with latency around 34ms. I have this: 1. DRBD version: 8.3.7 (api:88/proto:86-91) 2. Several virtual machine images on the DRBD volume. 3. deadline scheduler by default. 4. LVM on top of DRBD, and ext4 on top of this LVM. I did this: 1. I started 3 KVM VMs (mainly idle). 2. I started to copy a big file (50GB) into DRBD partition. 3. I started to use the VMs, mainly read-only operations, with some small writes. At some point, the VMs just froze while trying to read. So, I went to physical machine, and tried a "ls" on a directory inside the DRBD volume, that I hasn't saw before (so it was not cached)... ls command also froze.... access to cached data seems to be unaffected, then, I stopped the cp process (ctrl-z), and waited for network traffic to stop (patiently watching bwm). After network (replication) traffic stopped: all unfroze. Now, my understanding is that DRBD reads are local, and thus: I can't understand why writing would freeze the reads.... Any ideas? Thanks in advance, Ildefonso Camargo