Subsequent mirroring of the same data has a drastically lower impact. Initial SnapMirror replication is very disk and CPU intensive, partially due to the amount of data, partially due to background processes like deswizzling.You can obviously transition back into sync from async.These cache dumps are forwarded to the dest: a 1 min timeout in this process will relegate the replication to async status. Consistency Points are when the contents of NVRAM are flushed to the local disk, which occurs in certain situations, e.g. the NVRAM of the source is half full.After a 25s NVLOG Forwading timeout, the process is relegated to semi-sync status. In sync mode, writes to the source NVRAM are immediately transferred to the dest NVRAM.If the transfer is aborted/interrupted, it will begin replication again at the last checkpoint. NetApp advertises compression rates of 3.5:1 for Oracle, 2.7:1 for home directory, and 1.5:1 for Exchange.WAN compression devices handle latency/packet loss more efficiently, as well. SnapMirror compression obviously just compresses SnapMirror traffic.
RiverBed SteelHead) instead of SnapMirror to compress ALL SAN traffic (don't use both).
#HOW TO NETBOOT ONTAP SOFTWARE#
SnapMirror is Netapp's software that handles data replication from one system to another, giving you another copy of your information. Engineers are extremely familiar with this reality, even if they've never heard of the Triple Constraint Triangle: You constantly negotiate with stakeholders to squeeze as much as you can out of each, but in the end you're dealing with a reality that most of your job is navigating those constraints. This chapter provides information on parsing and modifying the multipath.In project planning, it's well known that there are three competing constraints: time, money, and scope. It is very common that storage vendors provide the most adequate options for Linux, including minimal kernel and multipath-tools versions required.ĭefault configuration values for DM-Multipath can be overridden by editing the /etc/nf file and restarting the multipathd service.
#HOW TO NETBOOT ONTAP INSTALL#
This doesn’t mean the default configuration variables should be used in production: they don’t treat important parameters your storage might need.Ĭonsult your storage manufacturer’s install guide for the Linux Multipath configuration options. Multipath is usually able to work out-of-the-box with most common storages. Device Mapper Multipathing - Introduction Device Mapper Multipathing - Configurationĭevice Mapper Multipath will be referred here as multipath only.īefore moving on with this session it is recommended that you read: 1.