<div dir="ltr"><div><div><div><div><div>Dear drbd users,<br><br></div>I am currently facing a problem with drbd replication. I set up an HA nas using heartbeat and drbd. The drbd disk is shared through NFS to a proxmox server which is running VM and CT. Those ct and vm are stored on the nas. <br>
<br></div>My problem is that when I am copying big files ( more than 1 GB) my VM and CT are freezing, for example apache on my vms is not answering to http request which is a real issue for us because vms are hosting our web applications. <br>
<br></div>It seems that we have some congestion issues somewhere however we cannot use protocol A and on-congestion parameters because we need the two nodes to be always synchronised. The two nas are using a Gigabit ethernet connexion for drbd and nfs. <br>
<br></div>Here is my .res file:<br>resource btrfs {<br> protocol C;<br> startup {<br> wfc-timeout 0;<br> degr-wfc-timeout 120;<br> become-primary-on nas1;<br> }<br>
disk {<br> on-io-error detach;<br> al-extents 3389;<br> disk-barrier no;<br> disk-flushes no;<br> }<br><br><br><br> net {<br> after-sb-0pri discard-older-primary;<br>
after-sb-1pri call-pri-lost-after-sb;<br> after-sb-2pri call-pri-lost-after-sb;<br> max-buffers 8000;<br> max-epoch-size 8000;<br> sndbuf-size 512k;<br>
}<br><br> on nas1 {<br> device /dev/drbd0;<br> disk /dev/md3;<br> meta-disk internal;<br> address ***.***.***.***:7788;<br> }<br>
on nas2 {<br> device /dev/drbd0;<br> disk /dev/sda3;<br> meta-disk internal;<br> address ***.***.***.***:7788;<br> }<br>}<br><br></div><div>
When I copy big files (using dd or rsync) cat /proc/drbd have flags a,b or n which means that there is congestion.<br><br></div><div>I have tried with protocol B but it doesn't change anything. I have tried to use c-min-rate and c-max-rate but I am not sure about which values I should use and it didn't seem to have any effect.<br>
</div><div><br></div><div>I hope you could help me because it is a huge problem for us here. We need in the same time our drbd replication to stay uptodate but also our vm and ct to work I don't need them to be as fast as usual but just not frozen. I cannot let all my VMs frozen each time there is a copy biger than 3Gb happening on the NAS.<br>
<br></div><div>I have tried and read a lot about it on the internet but I couldn't find any solution so I hope that someone here could help me to solve this problem.<br><br></div><div>Thanks and regards,<br></div><div>
David<br></div></div>