Hi guys,<br><br>a) 4TB Soft Limit when using External Meta Disk<br><br>I've noticed that there's a 4TB soft limit in place when using an External Meta Disk.<br>(i.e, "meta-disk /dev/sdx1[0]" inside your drbd.conf file in the "net" section)<br>
<br>Pretty sure this isn't anything to do with weird math or stuff, because it's limited at *exactly* 4,000,000MB if you use a disk larger than 4TB - (I tried with a 6TB array and a 5TB array to) rather than our usual power-of-two-number.<br>
<br>After pouring through loads of forum posts, I sincerely doubt this has anything to do with the size of my external meta disk - for 4TB you only need somewhere around ~180MB - and I've tried with 2GB and 8GB meta disks.<br>
<br>You should be able to replicate this as of "version: 8.3.1 (api:88/proto:86-89)".<br><br>To draw a contrast, you can try those very same arrays and use the default internal meta-disk (i.e, "meta-disk internal" inside your drbd.conf file).<br>
<br>---<br><br>b) Increased Performance with External Meta Disks<br><br>Apart from that, after running loads of dd-write's, I've personally found that using an External Meta Disk greatly boosts performance, especially in sync'ing - my results were on the average:<br>
<br>60,544 (62,132) K/sec - External meta disk<br>46,072 (46,204) K/sec - Internal meta disk<br><br>You can see a clear 15 to 25MB/s increase, even with initial sync.<br><br>Thought I'd just share this.<br><br><br>Thanks.<br>
<br>Regards,<br><br>Kelvin Leong<br>