Log Correlation Engine Hardware Requirements

The following hardware recommendations for LCE are to be used as a general guide. Enterprise networks can vary in performance, capacity, protocols, and overall activity. Resource requirements to consider for deployments include raw network speed, the size of the network being monitored, and the configuration of the application. Processors, memory, and network cards will be heavily based on the former. Disk space requirements will vary depending on usage based on the amount and length of time data is stored on the system.

The hardware requirements for LCE change based on the number of events being processed.

Estimating Events

The following table provides the estimated average number of events from various sources.

Devices	Number of Estimated Events
1 workstation/laptop	0.5 events/sec
1 web-facing app server	20 events/sec
1 web-facing firewall/IDS/IPS	75 events/sec
1 internal application server (low volume)	5 events/sec
1 internal application server (high volume: IIS, Exchange, AD)	20 events/sec
1 internal network device	2 events/sec

To convert your event rate to bytes per day, Tenable recommends that you multiply your total events/second by 250 bytes/event and multiply by 86,400 seconds/day.

Tip:

You can use the following calculator to determine the total number of events per second as well as the bytes per day.

Workstations

Web-facing Application Servers

Web-facing Firewalls/IDS/IPS

Internal Application Servers (low volume)

Internal Application Servers (high volume: IIS, Exchange, AD)

Internal Network Devices

events/second * 250 bytes/event * 86,400 second/day = 0 bytes/day

System Specification

The following table specifies the system requirements based on the number of events the LCE server is processing.

Version	Installation scenario	RAM	Processor	Hard disk	Hard disk space
6.x	One LCE server with PostgreSQL processing less than 5,000 events per second	22 GB	8 cores	10,000 to 15,000 RPM HD, or SSD of equiv. IOPS capability, in RAID 0/10 configuration	2.4 x Licensed storage size
	One LCE server with PostgreSQL processing between 5,000 and 20,000 events per second	30 GB	16 cores	15,000 RPM HD, or SSD of equiv. IOPS capability; RAID 0/10 configuration
	One LCE server with PostgreSQL processing greater than 20,000 events per second	58 GB or more	24 or more cores	SSD of IOPS capability at least equiv. to a 15,000 RPM HD; RAID 0/10 configuration

The LCE server requires a minimum of 20 GB of storage space to continue running and storing logs. If less than 1 GB is available, the Log Engine (lced) process will stop gracefully and refuse to store additional logs. The current system disk space is visible on the Health and Status page of the LCE interface.

File System Recommendations

Placing your activeDb on a networked file system (e.g. NFS) will result in inadequate system performance. Tenable recommends that you use EXT3, EXT4, XFS, or ZFS; and that you pay close attention to the mount options. Here are the mount options we suggest using, and the mount options we suggest staying away from:

If your file system is:	It is recommended that you use:	It is not recommended to use:
EXT3, EXT4, XFS	`noatime`	`atime` or `strictatime` or `relatime` or `diratime` or No `*atime` at all.
EXT3	`barrier=0`	`barrier=1`
EXT4	`barrier=0` or `nobarrier`	`barrier=1` or `barrier`
XFS	`nobarrier`	`barrier`
EXT3, EXT4	`data=writeback`	`data=journal` or `data=ordered` or No `data=*` at all.
ZFS	`atime=off`	`atime=on` or `relatime=on` or No `*atime` at all.
ZFS	Hardware-dependent	`compression=gzip` or `compression=gzip-N` or `compression=zle` `compress=gzip` or `compress=gzip-N` or `compress=zle`
ZFS	`logbias=throughput`	`logbias=latency` or No `logbias` at all.
ZFS	`primarycache=metadata`	`primarycache=all` or `primarycache=none` or No `primarycache=*` at all.
ZFS	Hardware-dependent	`recordsize=512` or `recordsize=1024` or `recordsize=2048` or `recordsize=4096`