Knowledge Collection: Planning for and using Domino for Linux on zSeries

In order to maintain the stability, performance and serviceability of a Lotus® Domino® Server for Linux on zSeries, a number of base configuration requirements must be met. The purpose of this document is to provide a high-level review of those requirements most often missed by customers who are either new to the zSeries platform or Domino.

This knowledge collection is intended to serve as a checklist of base requirements for a Domino server running on Linux for zSeries.

Contents:
Software maintenance
Configuring the Domino server to generate diagnostic logs
Known problems that inhibit data collection
Configuring adequate memory
Verifying Linux settings
Notes.ini parameters
Domino Server document
More information

• Novell Linux Operating Systems (SuSE)

• Red Hat Enterprise Linux

• z/VM

• Enable notes console log capture by setting the notes.ini parameter(s) Console_Log_Enabled=1 and/or ServerController=1.

• Console and controller logs are stored in the following directories, respectively:

/notesdata/IBM_TECHNICAL_SUPPORT
- and -
/notesdata

• nsd -memcheck will automatically run by default, if the Domino server crashes.

• Do not disable memcheck in the Fault Recovery section of the Domino Server Document, unless directed to do so by IBM Domino Support. If memcheck has been disabled, you will see "FaultRecoveryNSDArgs=-nomemcheck" in the server notes.ini file.

• Output from the nsd.sh shell script is automatically written to ../IBM_TECHNICAL_DIRECTORY subdirectory, but can be redirected using the notes.ini parameter, NSD_LOGDIR = <path>.

• Enable notes core dumps by setting the notes.ini parameter, Debug_enable_core=1. The core filename will be in the format core.12345 where "12345" represents the PID of the failing process.

• Redirect core files to a directory on a filesystem with adequate disk space to accommodate very large files, in the range of 2-3 GB each, by using the notes.ini parameter: debug_core_path=/path

• Domino Server Fault Recovery fails for Domino 7.0.2 for SuSE Linux Enterprise Server (SLES) 10 on zSeries (#1248185)

• Domino 7 server crash fails to produce a valid CORE dump and NSD with Java agents enabled

• The GNU debugger (gdb) is required to collect stack information, and it should be installed under the directory /usr/bin. Ensure the Domino server ID has permission to execute /usr/bin/gdb. You can manually run NSD to verify that call stacks are being generated.

zLinux Addressing	Domino	REAL Memory (OS + file cache)	SWAP
31-bit	6.5.x, 7.0.x / 31-bit application	2 GB total	512 MB - 1 GB
64-bit	7.0.x, 8.0.x / 31-bit application	2 GB per DPAR 2 GB for Linux	250 - 300 MB
64-bit	8.5.x / 64-bit application	2 GB per DPAR 2 GB for Linux	250 - 300 MB

• With 31-bit zLinux, IBM recommended configuring only one fully loaded DPAR per zLinux image.

• If you are running Domino on a 64-bit OS, the original 31-bit zLinux limitations do not apply. IBM recommends consolidating your DPARs to allow for fewer zLinux guests. You should then be able to allocate the memory Domino wants into the current physical memory in each z/VM. For example, if you consolidate from one DPAR per guest to three DPARs per guest with 19 GB central and 3 GB expanded memory, you will be running Domino with less physical memory, while at the same time giving Domino access to more real storage.

• Domino takes about 1 week to reach its full memory size. After about 3-4 days, it is around 90%, depending on what features are active, with the final 10% coming over the next couple of days. Be sure you are measuring memory usage after one full week of load.

• In an environment where the z/VM memory is over-committed, you will see workload spikes in Domino, since z/VM has to page the Domino guest and elongate transaction times. This has been documented by both benchmarks and PMRs, where fixing the paging rates resolved performance and scalability issues.

• Domino does not match the workload profiles of print servers, web servers or other workloads you may have seen under z/VM. These environments tend to 'go to sleep' when no user loads are active. This is not the case with Domino.

soft  nofile  20000
hard  nofile  49152

/proc/sys/fs/file-max                     = 131072
/proc/sys/net/ipv4/tcp_fin_timeout        = 15
/proc/sys/net/ipv4/tcp_max_syn_backlog    = 16384
/proc/sys/net/ipv4/tcp_tw_reuse           = 1
/proc/sys/net/ipv4/ip_local_port_range    = 1024    65535

• Debug_ThreadID=1

• Console_Log_Enabled=1 and/or ServerController=1

• Debug_enable_core=1

• NSF_BUFFER_POOL_SIZE_MB=<megabytes>
  Lotus® Domino® 6 and Domino 7 server
  - NSF buffer pool must be set to some value. (range = 200 - 400)
  Lotus® Domino® 8 and 8.5 server
  - NSF buffer pool will default to 400 MB or 1024 MB, depending on Domino version. Do NOT set this parameter unless otherwise recommended by IBM Support.

Operating System	Domino 6/7 32-bit Default Maximum UBM Size	Domino 8 32-bit Default Maximum UBM Size	Domino 8.5 64-bit Default Maximum UBM Size
zOS	none	400 MB	n/a
zLinux		400 MB	1024 MB

• NSF_DbCache_Maxentries=<# of databases>

• MinNewMailPoll=<10 minutes or greater>

• FT_FLY_INDEX_OFF=1

• Disable_bcc_group_expansion=1

• View_Rebuild_Dir=<path>

• Server_Session_Timeout=<30 to 60 minutes>

• TRANSLOG_HardwareCompress=1 (this is the default)

• MailBoxDisableTXNLogging=1

• Schedule_Disabletxnlogging=1

• Log_DisableTXNLogging=1 (Available in 7.0.2+)

• Fault Recovery

• Transaction Logging