Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Dear all, I ran into high latency with drbd 8.3.0, on the same hardware where drbd 0.7 was OK. I have created a test system Yesterday, two Lenovo Thinkcenter PCs, P4 3.0 GHz, Intel Chipset, 1 SATA disk in each PC, Gigabit Ethernet, one cable between them. I've installed Debian Etch on each of them, and drbd 0.7 that came with Etch. Drbd 8.3.0 was compiled by me. One goal was to verify that 0.7 -> 8 version upgrade goes without data loss. That is succeeded, there was no data loss. I have tested the performance as described in the performance tuning webinar. Hdparm and dd showed that the disks are capable of reading and writing at about 62 MByte/sec. The disk latency for each node: dd if=/dev/zero of=/dev/sda3 bs=512 count=1000 oflag=direct node1: 512000 bytes (512 kB) copied, 0.158945 seconds, 3.2 MB/s node2: 512000 bytes (512 kB) copied, 0.158367 seconds, 3.2 MB/s For initial sync, I put resync rate to 60 MByte/sec so that it finishes quickly. The actual resync rate was around 48 MByte/sec. Throughput was OK with 8.3.0, bs=300M count=1, 60.3 MByte/sec. Latency with drbd 0.7 was acceptable also: dd if=/dev/zero of=/dev/drbd0 bs=512 count=1000 oflag=direct 512000 bytes (512 kB) copied, 0.308893 seconds, 1.7 MB/s Latency with drbd 8.3.0 was very bad: dd if=/dev/zero of=/dev/drbd0 bs=512 count=1000 oflag=direct 512000 bytes (512 kB) copied, 8.36032 seconds, 61.2 kB/s It was not resyncing, there was no other activity on the PCs. I've also tried with drbd 8.2.6, same results. Also tried with Debian Etch 2.6.18 and 2.6.24-etchnhalf kernel, same results. drbd.conf was basicly default, only put in disk and network parameters, resync rate was changed to 20 Mbyte/sec, and al-extents 1201. What could cause this problem? Best regards, lanlaf