On the question of whether to have a ZIL device and/or an L2ARC device and how to implement it, there are general answers, but to make specific determinations, I would say you should measure or model your own workload in terms of IOPS, read/write ratio and cache hit ratio. If you are already running something like your planned workload, there are tools that can help you measure the relative utilization of these facilities and apply the results to determine where you need what, how big and how fast. If not, there a lot of valuable discussions about these issues that you will want to read in consideration of your own objectives. Brendan Gregg's blog comes to mind. I think Ben Rockwood has written on this too. Even Oracle has published some worthwhile material on it. It is probably worth returning to the idea of searching Google.
But for examples, if you have ample DRAM for ARC, your workload might not need much L2ARC. If you have just a crushing write IO load, soup up the ZIL device. For a busy general purpose server, take a balanced approach. For a quiet general purpose server, take a frugal approach. It really is a matter of knowing how these help a workload and where your specific workload needs the most help. On Thursday, January 21, 2016, Alessio Ciregia <[email protected]> wrote: > Let's say I want to buy a new server. > I know that I could search it on google, but I would like some advice > related to disks configuration in order to separate ZIL and L2ARC from > data: how many SSD, and wich size? Mirror, stripe? > I would like some real example from you. What is your configuration? > > Thanks in advance. > > -- *John Burwell* Systems Administrator 16945 Northchase Drive, Suite 1610, Houston, Texas 77060 *M* 281-874-2110 *D* 281-875-7997 *C* 713-269-8605 crystaphase.com ------------------------------------------- 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
