In 1989 a 4mb stick of ram was like $800. RAM is cheap despite price fixing.
Having recently maxed out the 64mb of RAM on my personal IPX in like 1994, I remember telling Len Rose I can’t imagine having a gigabyte of RAM. He laughed at me. Now I sit on racks of systems with 768gb of RAM. RAM is cheap. J. Sent from my iPhone > On Aug 23, 2018, at 6:08 PM, Rich via openzfs-developer > <developer@lists.open-zfs.org> wrote: > > Not every board can take ass-tons of RAM, and DDR4 RAM prices have > gone markedly up in the last 2 years, not down. (There's even a fun > price-fixing lawsuit or two in the works.) > > You'd also need to buy a decently high-end chip to exceed 128 GB of > RAM on your server. > > So while I agree the need for L2ARC in a number of situations has gone > down, it's hardly limited to the "highly budget oriented plays." > > - Rich > >> On Thu, Aug 23, 2018 at 8:42 PM, Jason Matthews <ja...@broken.net> wrote: >> >> Maybe I am doing it wrong but I am using NVMe for primary storage and ass >> tons of ram for arc. >> >> I think L2ARC is relegated to the highly budget oriented plays these days as >> RAM is soooo cheap. Buy some more ram and fooor-get-about it. >> >> J. >> >> Sent from my iPhone >> >> On Aug 23, 2018, at 1:07 PM, Sanjay Nadkarni <sanjay.nadka...@nexenta.com> >> wrote: >> >> Found this link for FreeBSD too >> http://www.brendangregg.com/blog/2015-03-10/freebsd-flame-graphs.html >> >> -Sanjay >> >> >> >> On 8/23/18 1:02 PM, Sanjay Nadkarni wrote: >> >> Would be useful if you could get flamegraphs when you run into this. See >> https://github.com/brendangregg/FlameGraph >> >> Once we have that, the we can have a better understanding of what's going on >> and we can dtrace it further to figure it out. >> >> -Sanjay >> >> >> >> On 8/23/18 5:47 AM, w.kruzel via openzfs-developer wrote: >> >> It's interesting what you said, as I have two examples (both with different >> Intel nvme disks) that show otherwise. >> >> Being nvme, I was expecting read performance from L2ARC at 2GB/s+ levels, >> yet I only get ~200MB/s read speeds when I certainly know it is being read >> from L2ARC. >> >> When tested (details in my earlier post), I can get the same speed with >> nvmecontrol perftest that is single threaded. >> Multi threaded perftest gives 2GB/s + output. >> >> I also have this raised with FreeNAS where one of their devs tested it on >> other make L2ARC he had installed and confirmed that it looks like single >> threaded process. >> >> Can someone look into this please? >> It is a major performance hit for L2ARC, making it not really fit for >> purpose :( >> >> Kind regards, >> Wojciech Kruzel >> >> >> >> openzfs / openzfs-developer / see discussions + participants + delivery >> options Permalink ------------------------------------------ openzfs: openzfs-developer Permalink: https://openzfs.topicbox.com/groups/developer/Tf62628db027682f7-M50ec0761702c2cd1b788b987 Delivery options: https://openzfs.topicbox.com/groups/developer/subscription
