On 1/14/26 21:45, Mark Millard wrote:
FYI for another issue,
I would never recommend swapping to a file in a file system (vnode),
especially to a zfs file:
QUOTE ( https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=206048#c7 )
On 2017-Feb-13, at 7:20 PM, Konstantin Belousov <kostikbel at gmail.com>
wrote on the freebsd-arm list:
. . .
swapfile write requires the write request to come through the filesystem
write path, which might require the filesystem to allocate more memory
and read some data. E.g. it is known that any ZFS write request
allocates memory, and that write request on large UFS file might require
allocating and reading an indirect block buffer to find the block number
of the written block, if the indirect block was not yet read.
As result, swapfile swapping is more prone to the trivial and
unavoidable deadlocks where the pagedaemon thread, which produce free
memory, needs more free memory to make a progress. Swap write on the
raw partition over simple partitioning scheme directly over HBA are
usually safe, while e.g. zfs over geli over umass is the worst construction.
END QUOTE
I have in the past suffered such consequences.
That's good to say because everybody is saying that it is not
recommended but most of the time people have no first hand experience of
a failure.
While this system have a few GBs of swap I removed it temporarily and I
used a zvol for swap. When I am done it will have the traditional swap
partition...
