Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Lars Ellenberg schrieb: > uhm, what does your cpu say to dd if=/dev/hda of=/dev/null ? > or to dd if=/dev/zero of=scratchfile ? root at via1:/mnt/nb0# dd if=/dev/zero of=scratchfile 2488220+0 Records ein 2488219+0 Records aus 1273968128 bytes transferred in 156,543794 seconds (8138094 bytes/sec) CPU on via1 85-95% CPU on via2 30-40% (identical hardware on both nodes) Here the CPU consumption seems to be the limit, or maybe ext3. With drbd full-sync I get 11.5 MB/sec -> 50% CPU on both nodes. Obviously drbd full-sync is _very_ efficient. Do it reverse: root at via1:/mnt/nb0# dd if=scratchfile of=/dev/zero 2488220+0 Records ein 2488220+0 Records aus 1273968640 bytes transferred in 25,523378 seconds (49913794 bytes/sec) CPU 70% Here the disk is the limit, 50 MB is identical to hdparm. > this is most likely NOT drbd consuming cpu, but _tcp_ used by drbd... Yes, drbd0 consumes the half directly. > and might be reduced considerably by using NICs that do the tcp work > themselves (and nic drivers that are aware of it). Don't know. # lspci -v 00:14.0 Ethernet controller: Advanced Micro Devices [AMD] 79c970 [PCnet32 LANCE] (rev 36) Subsystem: Allied Telesyn International AT-2450 10/100 Fast Ethernet Flags: bus master, medium devsel, latency 32, IRQ 10 I/O ports at e000 [size=32] Memory at df002000 (32-bit, non-prefetchable) [size=32] Expansion ROM at <unassigned> [disabled] [size=1M] Capabilities:  Power Management version 1 For my purposes the configuration is faster than needed. The hosted low traffic websites, 1 GB traffic per month, produce significantly below 10% CPU. > (and probably by using zero copy network writes as we do in 0.7) Benchmark figures for the audience? Helmut Wollmersdorfer