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A community for the ZFS filesystem.

ZFS is an opensource COW filesystem used by enterprise and serious homelabbers for it's data safety and extensive feature set.

OpenZFS is the active branch now developed primarily for Linux with a port to it's FreeBSD roots.

This community is here to answer questions and discuss topics related to the use of ZFS in the wild.

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ikidd

ZFS Swap question (self.zfs)

submitted 10 months ago* (last edited 10 months ago) by JustineSmithies to c/zfs

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One for those running #ZFS on #Linux systems. I realise that you can't have hibernate aka suspend to disk on a swap in the encrypted zpool but if you don't use hibernation then is it OK to use swap using the likes of the command example below to set it up in the encrypted pool?

I should point out that I'm thinking of switching from my current Void Linux luks lvm setup to Void with fully encrypted zpool and zfsbootmenu on my ThinkPad P14s AMD Gen 1which has 16Gb ram that I may upgrade to 40Gb. It also has a 1Tb nvme.

zfs create -V "${v_swap_size}G" -b "$(getconf PAGESIZE)" -o compression=zle -o logbias=throughput -o sync=always -o primarycache=metadata -o secondarycache=none -o com.sun:auto-snapshot=false "$v_rpool_name/swap"

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[–] [email protected] 2 points 10 months ago* (last edited 10 months ago)

I haven't used swap on zvol myself, but I've read about issues in low-memory situations, like this one: https://github.com/openzfs/zfs/issues/7734

To write to swap, zfs needs to allocate ARC memory. But to do that, it would need to write to swap...

Consider using zramswap, that's probably the easiest solution.