> My ZIL is never going to need more space than is required to store the last > ~5 seconds of write data, so even a 32 GB drive is going to go 90% unused.
Keep in mind that SmartOS is heavily used in datacenters for databases and virtualization, which imply a high amount of synchronous writes. Take virtualization: writes in KVM have to be treated pessimistically and thus are synchronous and go to the ZIL. A ZIL doesn't take much space on a slog, but slog endurance is crucial because if the device dies performance will fall off a cliff for many workloads; performance is often an important part of correctness, so we can't have that. Due to how SSDs work, all that extra space isn't being wasted: it improves the device's endurance. Also, L2ARC is less useful than you'd think. Unless you've characterized your workloads and/or done active benchmarking -- which is something only you can do -- and found that L2ARC removes a significant bottleneck, chances are it'll benefit your workload less than you hope. Marsell ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
