Chris Moore

Did you get this figured out?

Why do you want any SSDs in a backup system? Does it need to be iSCSI or can it be a regular SMB share? The iSCSI connection is going to always be slower because of the block storage nature of the interface. You should check this resource on the FreeNAS forum: https://www.ixsystems.com/community/threads/some-differences-between-raidz-and-mirrors-and-why-we-use-mirrors-for-block-storage.44068/ Normal SSDs are not fast enough to be used as SLOG and you would only need a maximum of 30 or 40 GB of SLOG anyhow. There are some great articles about that here: The ZFS ZIL and SLOG Demystified http://www.freenas.org/blog/zfs-zil-and-slog-demystified/ Some insights into SLOG/ZIL with ZFS on FreeNAS https://www.ixsystems.com/community/threads/some-insights-into-slog-zil-with-zfs-on-freenas.13633/ Testing the benefits of SLOG using a RAM disk! https://www.ixsystems.com/community/threads/testing-the-benefits-of-slog-using-a-ram-disk.56561/ SLOG benchmarking and finding the best SLOG https://www.ixsystems.com/community/threads/slog-benchmarking-and-finding-the-best-slog.63521/

You used to be able to do that on the older versions of FreeNAS, a few years ago, but you can't do it any more.