Yury & Oracle Community
Sharing experience implementing Direct NFS
© 2012 – Pythian
Contributors list From Twitter John Piwowar (@jpiwowar)Leighton L. Nelson (@leight0nn)Kevin Closson (@kevinclosson)Guenadi Jilevski (@gjilevski)Simon Haslam (@simon_haslam)neto from Brazil (@netofrombrazil)Frits Hoogland (@fritshoogland)Martin Bach (@MartinDBA)Gwen (Chen) Shapira (@gwenshap)Avi Miller (@Djelibeybi)Marcin Przepiorowski (@pioro)Arup Nanda (@arupnanda)Martin Berger (@martinberx)Martin Bach @MartinDBALook in slides notes for TW discussions
https://dl.dropbox.com/u/28277005/DNFS%20exp%2004.pptx
© 2012 – Pythian
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Google: Yury Oracle
Twitter, LinkedIn, Blog, Slideshare,YouTube
Oracle ACE (RAC SIG international chair, Sydney Oracle Meetups)
Oracle Certified MasterOracle DBA with 15+ years experience
Why Yury[phone|email]
I like my job, I like what I do, I like to share knowledge, I like to help others to share knowledge, I like to learn, I like my job.
© 2012 – Pythian
Why Direct NFS
Network IO
SPEEDEasy to use +RAC
© 2012 – Pythian
Load Profile Per Second~~~~~~~~~~~~ --------------- DB Time(s): 19.6 DB CPU(s): 0.8 Logical reads: 12,219.1
Physical reads: 12,141.31.7ms
Load Profile Per Second~~~~~~~~~~~~ --------------- DB Time(s): 19.6 DB CPU(s): 5.2 Logical reads: 38,277.5
Physical reads: 38,156.10.5ms
k NFS d NFS
100% 300%Oracle VM, PIO SLOB test, ram disk mounted via 127.0.0.1 backloop device, other bottlenecks but kernel have been excluded, “db file sequential read” aka
random readsDirect storage 0.36 ms
© 2012 – Pythian
It isn’t about data files only !File Type Supported
Control file YES
Data file YES
Redo log file YES
Archive/Flashback log file YES
Backup files YES
Temp file YES
Datapump dump file YES blog “Direct NFS speeds up Data Pump”
OCR files NO
spfile YES
passwd file YES
ASM files YES blog “Reasons for using ASM on NFS”
Voting files NO
Audit files NO
Database trace files NO
External tables NO
Direct NFS: FAQ [ID 954425.1]
RDBMS file type support matrix for Direct NFS client
Direct NFS Concepts
© 2012 – Pythian
IO ClientOracleprocess
kernel
File B
IO ClientOracleprocess
IO ClientOracleprocess
IO ClientOracleprocess
NFS service
IO ClientOracleprocess
IO ClientOracleprocess
k NFS d NFS
File CFile A File B File CFile A
NFS service
NFS client NFS client NFS client
Simplified
NFS client
Kern
el m
ode
Use
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ode
kern
el
© 2012 – Pythian
dNFS Setup simple version
mount NFS volumes
cd $ORACLE_HOME/rdbms/libmake -f ins_rdbms.mk dnfs_on
ls -l $ORACLE_HOME/lib/lib*od*11.so-rw-r--r--. 1 oracle oinstall 60431 Sep 17 2011 $OH/lib/libnfsodm11.so << dnfs-rw-r--r--. 1 oracle oinstall 60431 Oct 20 19:45 $OH/lib/libodm11.so # Oracle used-rw-r--r--. 1 oracle oinstall 12259 Sep 17 2011 $OH/lib/libodmd11.so << no dnfs
http://www.pythian.com/news/34425/oracle-direct-nfs-how-to-start/odm – stands for Oracle Disk Manager
Oracle processes use /etc/mtab to access NFS settings
© 2012 – Pythian
How can the dNFS usage be verified?Direct NFS: FAQ [ID 954425.1]
1. Just after the initialization parameters are listed in the alert log, you will see the following entry
Oracle instance running with ODM: Oracle Direct NFS ODM Library Version 2.0
2. Along with the message from the alert log, this query on v$dnfs_servers ensures that dNFS is truly being used (returns !=0 value):
select count(*) from v$dnfs_servers
( sometimes it isn’t true ;)
© 2012 – Pythian
How can the dNFS usage be verified?In my experience, the easiest and most reliable way is
1. lsof –p < dbw pid ># DNFS OFFlsof -p 725 | grep data01.dbforacle 725 oracle 262u REG ... /nfsimp/data01.dbf (192.168.51.21:/u01)
# DNFS ONlsof -p 6540 | grep 192.168.51.21oracle 6540 oracle 32u IPv4 ... TCP dbhost:26171->nfsserver:nfs (ESTABLISHED)
2. alert.logDirect NFS: channel id [0] path [IPnfs] to filer [KUKARACHA] via local [IPdb] is UPDirect NFS: channel id [1] path [IPnfs] to filer [KUKARACHA] via local [IPdb] is UP
Direct NFS advanced implementation
© 2012 – Pythian
dNFS setup – is documentedStep by Step - Configure Direct NFS Client on Linux [ID 762374.1]Step by Step - Configure Direct NFS Client on Windows [ID 1468114.1]=======================================================Set filesystemio_options at least to directIO. ALL database files.
● PART A -- SETTING UP THE NFS SERVER ON LINUX...iv) Make sure the NFS server will get started during boot of this server....
MOUNTING NFS ON THE CLIENT NODE / CLUSTER NODES ON LINUX...stgasm:/oraclenfs /oradata1 nfs rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,actimeo=0,vers=3,timeo=600 0 0# Please contact your NAS vendor for NFS mount option recommendations....
● PART B -- Configure Direct NFS Client (DNFS)i) Configure oranfstab file...Direct NFS Client can use a new configuration file or the mount tab file (/etc/mtab on Linux) to determine the mount point settings for NFS storage devices....
● PART C -- DNFS Workshop
Oracle® Grid Infrastructure Installation Guide11g Release 2 (11.2) for Linux3 Configuring Storage for Grid Infrastructure for a Cluster and Oracle RAC
© 2012 – Pythian
4 TCP/IP connections
Switch
Switch
IO ClientOracleprocess
NFS
serv
ice
dNFS oranfstab
NIC
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ICN
IC
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NIC
NIC
NIC
File B
File C
File A
NIC
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NIC
NIC
RA
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1Gbit
1Gbit
1Gbit
1Gbit
1Gbit
1Gbit
1Gbit
1Gbit
1Gbit
1Gbit
4 Gbit
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IO ClientOracleprocess
= Performance, Scalability, High Availability, Cost Savings
© 2012 – Pythian
dNFS oranfstab (things to remember)
●You can live without it (simple implementations)● DB Hangs When DNFS is Enabled on UEK kernel [ID 1460787.1]
●You may get confused reading though documentations
●Enabling Direct NFS Client Oracle Disk Manager Control of NFS● Server, Local, Path, Export, Mount, Mnt_timeout, Dontroute
● Server – any name you like (alias for a channel)● Local, Path - You can specify other IPs than in mtab● Export, Mount – local and remote mount points● Mnt_timeout – sessions drops a connection after the timeout● Dontroute – don’t use OS routeing table to send TCP/IP packages
Oracle Direct NFS configuration file explainedhttp://www.pythian.com/news/37259/oracle-direct-nfs-configuration-file-explained/
© 2012 – Pythian
dNFS oranfstab (things to remember)
●Direct NFS searches for mount entries in the following order1. $ORACLE_HOME/dbs/oranfstab # an instance specific2. /etc/oranfstab3. /etc/mtab
●You must restart an instance after adjusting oranfstab file
Troubleshooting & War stories
© 2012 – Pythian
One DNFS disadvantage
●It is relatively difficult to troubleshoot
●You will not find many DNFS messages in alert.log or trace files
●Sometimes Oracle SILINTLY switches from dNFS to kNFS
●This sections gives you useful troubleshooting hints
© 2012 – Pythian
Don’t mix old and new methods●Old methodcd $ORACLE_HOME/lib
mv libodm11.so libodm11.so_bak
ln -s libnfsodm11.so libodm11.so
●New/current methodmake -f ins_rdbms.mk dnfs_on
●If you enable dNFS using one method disable it the same way
© 2012 – Pythian
Magic words to rememberOracle® Grid Infrastructure Installation Guide 11g Release 2 (11.2) for Linux
If Oracle Database cannot open an NFS server using Direct NFS, then Oracle Database SILENTLY uses the platform operating system kernel NFS client.
1. lsof –p < dbw pid ># dNFS OFFlsof -p 725 | grep data01.dbforacle 725 oracle 262u REG ... /nfsimp/data01.dbf (192.168.51.21:/u01)
# dNFS ONlsof -p 6540 | grep 192.168.51.21oracle 6540 oracle 32u IPv4 ... TCP dbhost:26171->nfsserver:nfs (ESTABLISHED)
© 2012 – Pythian
NFS server reserved ports restrictionOracle® Grid Infrastructure Installation Guide 11g Release 2 (11.2) for Linux
Some NFS file servers require NFS clients to connect using reserved ports. If your filer is running with reserved port checking, then you must disable it for Direct NFS to operate. To disable reserved port checking, consult your NFS file server documentation.
In a simple NFS implementation that means:
cat /etc/exports
< dir > IP(...,insecure,...)
© 2012 – Pythian
dNFS: wtmax = /proc/fs/nfsd/max_block_sizeOracle® Grid Infrastructure Installation Guide 11g Release 2 (11.2) for Linux
Caution: Direct NFS will not serve an NFS server with write size values (wtmax) less than 32768.
...ALTER DATABASE OPENDirect NFS: attempting to mount /u02 on filer KUKARACHA2 defined in oranfstabDirect NFS: channel config is:channel id [0] local [192.168.51.30] path [192.168.51.21]Direct NFS: mount complete dir /u02 on KUKARACHA2 mntport 963 nfsport 2049Direct NFS: Invalid filer wtmax 525232 on filer KUKARACHA2Direct NFS: Filer wtmax 525232 must be an even multiple of 32768Thread 1 opened at log sequence 26...
© 2012 – Pythian
dNFS: wtmax = /proc/fs/nfsd/max_block_sizePythian’s dNFS related blog posts
root@nfsfiler01 sysconfig# cat /proc/fs/nfsd/max_block_size524288root@nfsfiler01 sysconfig# echo 1048576 > /proc/fs/nfsd/max_block_sizeroot@nfsfiler01 sysconfig# cat /proc/fs/nfsd/max_block_size1048576
...ALTER DATABASE OPENDirect NFS: attempting to mount /u02 on filer KUKARACHA2 defined in oranfstabDirect NFS: channel config is: channel id [0] local [192.168.51.30] path [192.168.51.21]Direct NFS: mount complete dir /u02 on KUKARACHA2 mntport 883 nfsport 2049Direct NFS: channel id [0] path [192.168.51.21] to filer [KUKARACHA2] via local [192.168.51.30] is UPDirect NFS: channel id [1] path [192.168.51.21] to filer [KUKARACHA2] via local [192.168.51.30] is UPBeginning crash recovery of 1 threads...
© 2012 – Pythian
init.ora events to set●If you are confused and need more information then set the following events and access NFS files
event "19392 trace name context forever, level 8" # kgnfs
event "19394 trace name context forever, level 8" # skgnfs
event "19396 trace name context forever, level 2" # kgodm
event="19398 trace name context forever, level 128"
alter system set event="19392 trace name context forever, level 8","19394 trace name context forever, level 8","19396 trace name context forever, level 2","19398 trace name context forever, level 128" scope=spfile;
● Read trace file, search MOS/Google, ask others ( Yury ;)
© 2012 – Pythian
ReferencesDirect NFS: FAQ [ID 954425.1]Example About How To Setup DNFS On Oracle Release 11.2 [ID 1452614.1]How to Setup Direct NFS client multipaths in same subnet [ID 822481.1]DB Hangs When DNFS is Enabled on UEK kernel [ID 1460787.1]DB hang and ORA-600 [2116] errors when enabling DNFS [ID 1484422.1]DNFS CANNOT MOUNT FILESYSTEM AND DATABASE FAILED WITH ORA-600 [2116] AFTER A REBOOT OF SERVER DUE TO POWER FAILURE [ID 1480788.1]DATABASE STARTUP HANGS AT MOUNTING CONTROLFILE WHEN DNFS IS ENABLED. [ID 971406.1]Database Startup Failed with "Direct NFS: please check that oradism is setuid“ [1430654.1]ORA-600 [2116] Using The Veritas Odm Lib Oracle Fails To Mount [ID 418603.1]OERI [2116] [900] during database mount with > 13 instances [ID 9790947.8]TESTCASE Step by Step - Configure Direct NFS Client (DNFS) on Windows [ID 1468114.1]Database Alert Log entries: Direct NFS: Failed to set socket buffer size.wtmax=[1048576] rtmax=[1048576], errno=-1 [ID 1352886.1]
@kevinclosson Oracle 11g, Direct NFS Client, An Oracle White Paper + http://bit.ly/QU3w82@leight0nn http://blogs.griddba.com/2012/02/direct-nfs-speeds-up-data-pump.html @rene_kundersma https://blogs.oracle.com/XPSONHA/entry/using_dnfs_for_test_purposes@yvelikanov http://www.pythian.com/news/tag/dnfs/
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Your best friends OR things to keep in mind
Network IO
SPEED
efficiency
© 2012 – Pythian
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