Hi. I am planning to convert several 11.2 FreeBSD Jails into bhyve VMs.
My bhyve setup uses a ZVOL for each VM (currently Debian and Ubuntu Linux using ext3/4) and I want to keep it that way for the new FreeBSD VMs. I really like the idea of having ZFS as file system inside the FreeBSD guests, but wonder if there are any strong points against running ZFS on top of ZFS. - Is the I/O performance of a FreeBSD guest with ZFS much worse compared to a UFS only guest or only e.g. 1/3 slower. Any numbers? - Wasted RAM allocation: Do FreeBSD guests with ZFS make any sense for small memory allocations < 2 GB? (Because ZFS caches will possibly consume most of the memory) - I/O bloat? Will you waste performance on the physical disks on the host server when running most of your bhyve guests with ZFS? - What ZFS send/receive performance can be expected in and out of a ZFS guest running on top of a ZVOL? (Is there an I/O penalty?) - Are there any ZFS or ZPOOL parameters inside the ZFS guest that should be tuned to reflect the situation that they are virtualized on a ZVOL? (maybe to save precious RAM) - Zpool Scrubbing inside the VM should not be necessary, right? - Can the file system journaling of a ZVOL hosted FreeBSD guest running UFS cope with a crash of the host server? Will the UFS journaling keep the file guest system integrity even if an older ZVOL snapshot of the VM will be rolled back (VM not running; Auto-Snapshot from the VM in state "running") Regards, Kai. _______________________________________________ freebsd-virtualization@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization To unsubscribe, send any mail to "freebsd-virtualization-unsubscr...@freebsd.org"
