<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head>
<body>
<div>Hello all,<br></div><div dir="auto"><br></div><div dir="auto">I have setup a Linux cluster on 2x CentOS 8 Stream machines - it has resources to manage a dual primary, GFS2 DRBD setup. DRBD and the cluster have a diskless witness. Everything works fine - I have the dual primary DRBD working and it is able to present an iSCSI LUN out to my LAN. However, the DRBD write speed is terrible. The backing DRBD disks (HDD) are RAID10 using mdadm and they (re)sync at around 150MB/s. DRBD verify has been limited to 100MB/s, but left untethered, it will get to around 140MB/s. If I write data to the iSCSI LUN, I only get about 10-15MB/s. Here's the DRBD global_common.conf - these are exactly the same on both machines:<br></div><div dir="auto"><br></div><div dir="auto">global {<br></div><div dir="auto"> usage-count no;<br></div><div dir="auto"> udev-always-use-vnr;<br></div><div dir="auto">}<br></div><div dir="auto"><br></div><div dir="auto">common {<br></div><div dir="auto"> handlers {<br></div><div dir="auto"> }<br></div><div dir="auto"><br></div><div dir="auto"> startup {<br></div><div dir="auto"> wfc-timeout 5;<br></div><div dir="auto"> degr-wfc-timeout 5;<br></div><div dir="auto"> }<br></div><div dir="auto"><br></div><div dir="auto"> options {<br></div><div dir="auto"> auto-promote yes;<br></div><div dir="auto"> quorum 1;<br></div><div dir="auto"> on-no-data-accessible suspend-io;<br></div><div dir="auto"> on-no-quorum suspend-io;<br></div><div dir="auto"> }<br></div><div dir="auto"><br></div><div dir="auto"> disk {<br></div><div dir="auto"> al-extents 4096;<br></div><div dir="auto"> al-updates yes;<br></div><div dir="auto"> no-disk-barrier;<br></div><div dir="auto"> disk-flushes;<br></div><div dir="auto"> on-io-error detach;<br></div><div dir="auto"> c-plan-ahead 0;<br></div><div dir="auto"> resync-rate 100M;<br></div><div dir="auto"> }<br></div><div dir="auto"><br></div><div dir="auto"> net {<br></div><div dir="auto"> protocol C;<br></div><div dir="auto"> allow-two-primaries yes;<br></div><div dir="auto"> cram-hmac-alg "sha256";<br></div><div dir="auto"> csums-alg "sha256";<br></div><div dir="auto"> verify-alg "sha256";<br></div><div dir="auto"> shared-secret "secret123";<br></div><div dir="auto"> max-buffers 36864;<br></div><div dir="auto"> rcvbuf-size 5242880;<br></div><div dir="auto"> sndbuf-size 5242880;<br></div><div dir="auto"> }<br></div><div dir="auto">}<br></div><div style="16px"><br></div><div style="16px">Respectfully,<br></div><div style="16px"> Tyler<br></div> </body>
</html>