<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Times New Roman; font-size: 12pt; color: #000000'><span>I noticed I did not reply to the list. So, here is the copy :</span><div><span><br></span></div><div><span style="background-color: rgb(255, 255, 255); ">Hi Eduardo,</span><div style="background-color: rgb(255, 255, 255); "><br></div><div style="background-color: rgb(255, 255, 255); ">When I had these horrible performances I was not in a good situations :</div><div style="background-color: rgb(255, 255, 255); ">- One 2GB disk SSD 7200RPM per node.</div><div style="background-color: rgb(255, 255, 255); ">- DRBD 8.3, Protocol C, Active-Active</div><div style="background-color: rgb(255, 255, 255); ">- 2 Network interfaces on a 100Mbits network switch.</div><div style="background-color: rgb(255, 255, 255); "><br></div><div style="background-color: rgb(255, 255, 255); ">Now that I added the SSDs, I'll test again. I'm currently looking on how to test. </div><div style="background-color: rgb(255, 255, 255); ">As I'm not interested in testing my OS cache, I'll reduce the memory to 1GB or less (with the mem=1024M kernel boot option), Install an ubuntu VM with 512MRam and PV disk drivers, and run either bonnie++ or iozone in these 4 conditions :</div><div style="background-color: rgb(255, 255, 255); ">- Local SSD</div><div style="background-color: rgb(255, 255, 255); ">- DRBD SSD in Active-Active</div><div style="background-color: rgb(255, 255, 255); ">- Local SATA</div><div style="background-color: rgb(255, 255, 255); ">- DRBD Sata in Active-Active (but with the meta-disk on SSD). (Where I was getting 30IOPS with bonnie++ in my VM before I moved meta-disk to SSD)</div><div style="background-color: rgb(255, 255, 255); "><br></div><div style="background-color: rgb(255, 255, 255); ">Regards,</div><span><br><span name="x"></span>François Delpierre<span name="x"></span><br></span><br><hr id="zwchr"><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>De: </b>"Eduardo Diaz - Gmail" <ediazrod@gmail.com><br><b>À: </b>"François Delpierre" <francois.delpierre@pivert.org><br><b>Cc: </b>drbd-user@lists.linbit.com<br><b>Envoyé: </b>Mardi 3 Janvier 2012 14:19:39<br><b>Objet: </b>Re: [DRBD-user] drbd performance issue on SATA<br><br>I check the Network link too, because some times the network are the<br>real problem.<br><br>Did you test the network interface?.<br><br>Did you change the the protocol to A for example.. and make more test.<br><br>In my experience the SSD disk has problems for broken.<br><br>http://www.codinghorror.com/blog/2011/05/the-hot-crazy-solid-state-drive-scale.html<br><br>What configuration are you creating? Active/active, Active/passive?<br>What filesystem?<br><br>regards!<br><br>On Sun, Jan 1, 2012 at 6:04 PM, François Delpierre<br><francois.delpierre@pivert.org> wrote:<br>> Hi,<br>><br>> I'm building a very low cost virtualization server for a Non Profit<br>> organization using 2 HP workstations (500€ each) (8GB Ram, 1.5TB, QuadCore<br>> AMD), Software Proxmox and DRBD for the data replication with dedicated<br>> gigabit & cross cable for the replication.<br>><br>> After setting up the replication (Protocol C), I had catastrophic<br>> performances, ( dropping to 30 IOPS after 60s of random writes ).<br>><br>> I also found a lot of reading, not fully explaining my terrific 30 IOPS on<br>> 7200RPM drives, but clearly pointing the necessity to have a battery backed<br>> up cache controller to sustain random writes generated by the meta-disk.<br>><br>> As the hardware makrket did change quite a lot recently, especially towards<br>> SSD, I immediately realized that 240GB SSD are half price than a small raid<br>> controller, a battery for the cache, and 2 small disks with reasonable<br>> performances (10rpm). So, I choose SSD.<br>><br>> I created 2 partitions on my SSD :<br>> - 128MB for external meta-disk of my slow SATA partition (750GB)<br>> - 240GB for a second DRBD resource, with internal meta-disk.<br>><br>> My questions :<br>> - Is there some recommendations on a SSD setup ?<br>> - Why is the external meta-disk that few documented ? I spent more than 1<br>> hour to find the syntax of the directive :<br>><br>> meta-disk<br>> /dev/disk/by-id/scsi-SATA_MKNSSDCR240GB_MKN1146A0000032XXX-part1[0];<br>><br>> And it's not clear to my what is the [0] at the end ?<br>><br>> Regards,<br>><br>> François Delpierre<br>><br>><br>> _______________________________________________<br>> drbd-user mailing list<br>> drbd-user@lists.linbit.com<br>> http://lists.linbit.com/mailman/listinfo/drbd-user<br>><br></div><br></div></div></body></html>