Hi, all, > Am 17.11.2016 um 11:16 schrieb Jan Bramkamp <[email protected]>: > Bhyve doesn't support page deduplication but it doesn't wire down guest > memory unless you asked it to, but you have to wire down guest memory to use > PCI passthrough. If I were picking VM hosts today I would go with LGA 2011 v3 > boards having least eight DDR4 slots per socket. Maybe use some nice >= 2TB > NVMe SSDs and suddenly your limited by CPU cycles and storage space instead > of IOPS and RAM.
Perhaps I'll describe the intention of this project. All your suggestions are great for a heavy virtualisation platform. In our case we just want a cheap, yet "reliable enough" platform to host a handful of rocket.chat instances. While rocket.chat claims FreeBSD support that's way behind compared to running the product on Linux. We found Ubuntu to be a good choice in this case. Unfortunately the application's architecture doesn't easily fit running multiple instances on one kernel/OS. The absence of current FreeBSD support rules out jails. So a full-fledged hypervisor is called for. And we will use a system with two mirrored SATA disks to run no more than 10 Ubuntu guests with at most 4 GB each and 100 GB of guest disk space. 1 or 2 TB of spinning rust in a mirror, that's all. At least rocket.chat is not performance hungry. The only issue I saw is RAM (CPU supports at most 32 GB) and the ZVOL "issue" I initially asked about. We will now provision them "sparse" with a small block size ... > An other thing I learned the hard way is that ZVOL are set in stone at the > ZVOL creation. You have to (cam)dd everything to change the block size. The > default ZVOL block size is 8K which isn't wrong but your guests need to align > their file systems (and swap) correctly or you'll suffer from write > amplification. And ZFS RAID-Z really sucks for such small block sizes. Use > mirrored VDEVs in your pools or you will suffer from massive metadata > overhead and disappointing IOPS. I attended Kirk's kernel class on last EuroBSDCon ;-) You are essentially preaching to the choir - but for the list archives and later searches sake, your work will probably do somebody else some good. Thanks again, Patrick -- punkt.de GmbH * Kaiserallee 13a * 76133 Karlsruhe Tel. 0721 9109 0 * Fax 0721 9109 100 [email protected] http://www.punkt.de Gf: Jürgen Egeling AG Mannheim 108285 _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-emulation To unsubscribe, send any mail to "[email protected]"
