Some questions raised by readers regarding Exadata simulator

Some questions raised by readers regarding Exadata simulator

Q1: Hi, Steven, I followed all of your steps but with no luck.  I encountered the below errors while creating flashcache, can you help me with this?

Initialization of celldisk CD_disk06_cell1 on /opt/oracle/cell11. completed.
ossmmap_map: mmap failed for DiskHT len: 234881024 as there is insufficient memory
max_mem 3512729600 perm_mem 2991546368 sga 486541016 pga 919080 (bytes)
ALERT: Flash Cache allocation failed. Check trace file for more info.
Cellsrv encountered a fatal signal 11
Errors in file /opt/oracle/cell11.  (incident=25):
ORA-07445: exception encountered: core dump [_ZN14FlashCacheCore12fcDeleteCoreEv()+284] [11] [0x000000048] [] [] []
Incident details in: /opt/oracle/cell11.
Exception [type: 11] [ADDR:0x48]
Cellsrv encountered a fatal signal 11

 A1: I just have succeeded in reproducing this error in my testing environment. I have the reason to believe that this issue lay in the memory size of your virtual machine. More specifically speaking, if you allocated more than 4 Gigabytes or more memory for your cell vm box, it is likely that you will hit this issue.

Pls reduce your memory size to 3 Gigabytes and it will eventually get fixed.

BTW: I have been using a old lenovo laptop, recently it was replaced by a new model.


Q2: I do not know too much about Chinese language though I would learn learn some of them one day while I have opportunity, but can you translated them to  English ?

A2: Thanks for your visiting. I do understand it is might be very difficult to read a language with Google translate you do not familiar with, some of the points might be lost or misunderstood while translating by robots. So I am considering to blog some of my articles in bilingual in  the future, nevertheless, before that most of them would be written in Chinese. Please drop me a line if you think it is valuable to you or it gonna benefit for more audiences.


Q3: Can I build this on my Linux Boxes? I mean not in a virtualbox.

A3: Of course you can, but please keep in mind that they are just simulator for testing purpose only and you can not build a fake Exadata.

CellCLI> list cell detail
	 name:              	 cell1
	 bbuTempThreshold:  	 60
	 bbuChargeThreshold:	 800
	 bmcType:           	 absent
	 cellVersion:       	 OSS_11.
	 cpuCount:          	 1
	 diagHistoryDays:   	 7
	 fanCount:          	 1/1
	 fanStatus:         	 normal
	 flashCacheMode:    	 WriteThrough
	 id:                	 5841beec-6ca5-46ea-b2dc-f7778c62f5cd
	 interconnectCount: 	 1
	 interconnect1:     	 eth0
	 iormBoost:         	 0.0
	 kernelVersion:     	 2.6.18-274.el5
	 makeModel:         	 Fake hardware
	 metricHistoryDays: 	 7
	 offloadEfficiency: 	 1.0
	 powerCount:        	 1/1
	 powerStatus:       	 normal
	 releaseTrackingBug:	 14522699
	 status:            	 online
	 temperatureReading:	 0.0
	 temperatureStatus: 	 normal
	 upTime:            	 0 days, 0:26
	 cellsrvStatus:     	 stopped
	 msStatus:          	 running
	 rsStatus:          	 running


Q4: Do you mind if I am just a little bit too lazy to build a one?

A4: Never mind, If you are having a hard time understanding Chinese. I will upload the  VBox images.Pls note that cell vm image has already been upload to my Google Drive, pls click the following link to download:

I will update this blog if db vm image has been uploaded.

all you have to do is

1. download and install Oracle VirtualBox, Vmware either, whatever.

2. download this image

3. import

4. you are done.


Q5: Can you clarity why there is no additional Exadata rpms have to be installed on DB nodes?

A5: That is a good question.

Firstly, I would like to say  it truly does. In fact, most of these features has been merged into Oracle Database binaries,  so you can not enable them if you are not using SAGE as your storage.

Sencondly, iDB, based on RDS, is a protocol running up on infiniband. infiniband drivers which  called OFED is built on Linux kernels. There is no such kind of packages installed on Exadata DB nodes simulator. So with this simulator, offloading is not likely to be working. Someone might argue that (s)he has already observed smart scans via Oracle database waiting events, unfortunately , that is not a truly offloading. It is just a demo to help you understand exadata mechanisms  better, you can not take it as seriously offloading.

Thridly, please note that In real life, db image involves no cell rpms, it only contains firmwares, drivers, kernel rpms, essential rpms for basical Linux etc. It is not necessary to install Exadata firmwares, drivers on a Virtual Machine cause there is no such kind of stuff.

Anyway, I am not from Exadata dev team, above are just my own understanding.




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