External Storage Options
You can use iSCSI, or NFS to provide an offboard storage solution.
Onboard disks provide a faster solution than offboard storage devices. Local disk storage on appliances supports JSA read speeds of 200 - 400 MBps and write speeds of almost 200 Mbps. When multiple appliances are deployed, performance and capacity scale at the same rate.
iSCSI uses a dedicated storage channel over standard Ethernet infrastructure, rather than a dedicated SAN network. For this reason, iSCSI can be the easiest to implement, most cost effective, and most readily available.
If you implement an iSCSI solution, then network capacity is shared between external storage access and management interface I/O. In this situation, you can configure a secondary network interface on a separate storage network.
Using a dedicated interface, you are limited to 1 Gbps and might experience only 200 MBps to 400 MBps. Your iSCSI storage device might provide only 25 MBps to 50 MBps I/O performance.
A Network File System (NFS) solution must not be used to store
active JSA data. You can move the
/store/backup file system to an external NFS.
/store file system is
mounted to an NFS solution, PostgreSQL data can be corrupted. If the
/store/ariel file system is mounted to NFS, JSA experiences performance issues.
Use NFS for tasks during off-peak times, tasks that involve batch file writes, and tasks that involve a limited volume of file I/O. For example, use NFS for daily configuration and data backups.
NFS storage operates over existing management Ethernet networks and is limited to performance levels of 20 MBps to 50 MBps. The NFS protocol might affect performance for file access, locking, and network permissions. Remediate the performance impact by using a dedicated network interface.
If NFS is used only for backups, the same NFS share can be used for each host. The backup files contain the system host name, which enables the identification of each backup file. If you are storing a long period of data on your NFS shares, consider a separate share or export for each appliance in your deployment.
External Storage Limitations
Multiple systems cannot access the same block device in a JSA deployment.
If you configure iSCSI in an HA environment, do not mount the iSCSI volumes on the secondary host while the primary host is accessing the volumes.
An external storage device must able to provide consistent read and write capacity of 100 MBps to 200 MBps. When consistent read and write capacity is not available, the following issues might occur:
Data write performance is impacted.
Search performance is impacted.
If performance continues to degrade, then the processing pipeline can become blocked and JSA might display warning messages and drop events and flows.
Offboard Storage in HA Environments
If you choose to move the
/store file system in a high-availability (HA) environment, the
/store file system is not replicated by using Disk
Replication Block Device (DRBD).
If you move the
/store/ariel file system to an offboard storage device and maintain the
/store file system on local disk, the
/store file system is synchronized with the secondary
HA host by using DRBD. By default, when your environment is configured
for HA, DRBD is enabled.