<div dir="ltr">Hi,<div><br></div><div>I'm trying to squeeze performance out of gluster on 4 80GB RAM 20-CPU machines where Gluster runs on attached block storage (Linode) in (4 replicate bricks), and so far everything I tried results in sub-optimal performance.</div><div><br></div><div>There are many files - mostly images, several million - and many operations take minutes, copying multiple files (even if they're small) suddenly freezes up for seconds at a time, then continues, iostat frequently shows large r_await and w_awaits with 100% utilization for the attached block device, etc.</div><div><br></div><div>But anyway, there are many guides out there for small-file performance improvements, but more explanation is needed, and I think more tweaks should be possible.<br></div><div><br></div><div>My question today is about performance.cache-size. Is this a size of cache in RAM? If so, how do I view the current cache size to see if it gets full and I should increase its size? Is it advisable to bump it up if I have many tens of gigs of RAM free? </div><div><br></div><div><br></div><div><br></div><div>More generally, in the last 2 months since I first started working with gluster and set a production system live, I've been feeling frustrated because Gluster has a lot of poorly-documented and confusing options. I really wish documentation could be improved with examples and better explanations.</div><div><br></div><div>Specifically, it'd be absolutely amazing if the docs offered a strategy for setting each value and ways of determining more optimal values. For example, for performance.cache-size, if it said something like "run command abc to see your current cache size, and if it's hurting, up it, but be aware that it's limited by RAM," it'd be already a huge improvement to the docs. And so on with other options.</div><div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial">The gluster team is quite helpful on this mailing list, but in a reactive rather than proactive way. Perhaps it's tunnel vision once you've worked on a project for so long where less technical explanations and even proper documentation of options takes a back seat, but I encourage you to be more proactive about helping us understand and optimize Gluster.</div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial">Thank you.</div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr">Sincerely,<br>Artem<br><br>--<br>Founder, <a href="http://www.androidpolice.com" target="_blank">Android Police</a>, <a href="http://www.apkmirror.com/" style="font-size:12.8px" target="_blank">APK Mirror</a><span style="font-size:12.8px">, Illogical Robot LLC</span></div><div dir="ltr"><a href="http://beerpla.net/" target="_blank">beerpla.net</a> | <a href="https://plus.google.com/+ArtemRussakovskii" target="_blank">+ArtemRussakovskii</a> | <a href="http://twitter.com/ArtemR" target="_blank">@ArtemR</a><br></div></div></div></div></div></div></div></div></div></div></div>
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