Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Well, at least you are getting much better performance than I am getting. I don't understand why even my local write performance is so much worse than yours. What sort of disk subsystem are you using? On Dec 21, 2007 11:52 AM, Carlos Xavier <cbastos at connection.com.br> wrote: > Hi, > I have been following this thread since i want to do a very similar > configuration. > > The system is running on Dell 1435SC each one with 2 dual core AMD Opteron > and 4GB of ram. > the network cards are: > 01:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5721 Gigabit > Ethernet PCI Express (rev 21) > 02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5721 Gigabit > Ethernet PCI Express (rev 21) > 06:00.0 Ethernet controller: Intel Corporation 82572EI Gigabit Ethernet > Controller (Copper) (rev 06) > > Right now it is running a OCFS2 over DRBD and we dont have Myqld database > over it yet. I run the commands to see the throughput of the write on the > disk. As you can see bellow is that when the DRBD is up and connected the > througput fall a litle below the middle of the value we got with it > disconnected. > > DRBD and OCFS2 cluster connected > > root at apolo1:~# dd if=/dev/zero bs=4096 count=10000 of=/clusterdisk/testfile > oflag=dsync > 10000+0 records in > 10000+0 records out > 40960000 bytes (41 MB) copied, 3.89017 s, 10.5 MB/s > > > DRBD connected and OCFS2 remote disconnected > root at apolo1:~# dd if=/dev/zero bs=4096 count=10000 of=/clusterdisk/testfile > oflag=dsync > 10000+0 records in > 10000+0 records out > 40960000 bytes (41 MB) copied, 3.65195 s, 11.2 MB/s > > DRBD remote stopped and OCFS2 local mounted > root at apolo1:~# dd if=/dev/zero bs=4096 count=10000 of=/clusterdisk/testfile > oflag=dsync > 10000+0 records in > 10000+0 records out > 40960000 bytes (41 MB) copied, 1.50187 s, 27.3 MB/s > > Regards, > Carlos. > > > > ----- Original Message ----- > From: "Art Age Software" <artagesw at gmail.com> > To: <drbd-user at linbit.com> > Sent: Thursday, December 20, 2007 7:35 PM > Subject: Re: [DRBD-user] MySQL-over-DRBD Performance > > > > On Dec 20, 2007 1:01 PM, Lars Ellenberg <lars.ellenberg at linbit.com> wrote: > >> > >> On Thu, Dec 20, 2007 at 11:08:56AM -0800, Art Age Software wrote: > >> > On Dec 20, 2007 3:05 AM, Lars Ellenberg <lars.ellenberg at linbit.com> > >> > wrote: > >> > > On Wed, Dec 19, 2007 at 04:41:37PM -0800, Art Age Software wrote: > >> > > > I have run some additional tests: > >> > > > > >> > > > 1) Disabled bonding on the network interfaces (both nodes). No > >> > > > significant change. > >> > > > > >> > > > 2) Changed the DRBD communication interface. Was using a direct > >> > > > crossover connection between the on-board NICs of the servers. I > >> > > > switched to Intel Gigabit NIC cards in both machines, connecting > >> > > > through a Gigabit switch. No significant change. > >> > > > > >> > > > 3) Ran a file copy from node1 to node2 via scp. Even with the > >> > > > additional overhead of scp, I get a solid 65 MB/sec. throughput. > >> > > > >> > > this is streaming. > >> > > completely different than what we measured below. > >> > > > >> > > > So, at this stage I have seemingly ruled out: > >> > > > > >> > > > 1) Slow IO subsystem (both machines measured and check out fine). > >> > > > > >> > > > 2) Bonding driver (additional latency) > >> > > > > >> > > > 3) On-board NICs (hardware/firmware problem) > >> > > > > >> > > > 4) Network copy speed. > >> > > > > >> > > > What's left? I'm stumped as to why DRBD can only do about 3.5 > >> > > > BM/sec. > >> > > > on this very fast hardware. > >> > > > >> > > doing one-by-one synchronous 4k writes, which are latency bound. > >> > > if you do streaming writes, it probably get up to your 65 MB/sec > >> > > again. > >> > > >> > Ok, but we have tested that with and without DRBD by the dd command, > >> > right? So at this point, by all tests performed so far, it looks like > >> > DRBD is the bottleneck. What other tests can I perform that can say > >> > otherwise? > >> > >> sure. > >> but comparing 3.5 (with drbd) against 13.5 (without drbd) is bad enough, > >> no need to now compare it with some streaming number (65) to make it > >> look _really_ bad ;-) > > > > Sorry, my intent was not to make DRBD look bad. I think DRBD is > > **fantastic** and I just want to get it working properly. My point in > > trying the streaming test was simply to make sure that there was > > nothing totally broken on the network side. I suppose I should also > > try a streaming test to the DRBD device and compare that to the raw > > streaming number. And, back to my last question: What other tests can > > I perform at this point to narrow down the source of the (latency?) > > problem? > > > _______________________________________________ > > drbd-user mailing list > > drbd-user at lists.linbit.com > > http://lists.linbit.com/mailman/listinfo/drbd-user > > > > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user >