Why drives with voting rights are always an odd number
I have a query that why voting disk are always recommended in odd numbers.The voting disk must reside on a shared disk that is accessible by all nodes in the cluster. For high availability, Oracle recommends that you have several disks with voting rights. Oracle Clusterware can be configured to manage records with multiple voting rights (multiplexing), but you must have an odd number of voting records, such as three, five and so on. Oracle Clusterware supports a maximum of 32 disks with voting rights. If you set a single voting disk, then you must use external mirror to provide redundancy.
A node must be able to access more than half the disks with right to vote at any time. For example, if you have five voting disks configured, then a node must be able to access at least three drives with right to vote at any time. If a node cannot access the required minimum number of discs with right to vote, it is expelled or removed from the cluster.
Here I have a table:
Total number of vdisk (n) Minimum vdisk required by nodes (> n/2) no vdisk can be failed at the same time
1 1 0
2 1 1
3 2 1
4 2 2
5 3 2
6 3 3
7 4 3
Here, it is clear that it does not matter as the vdisk 4 or 5, the number of vdisk can be failed at the same time would be 2. So, not sure why an odd number of voting records are recommended.
Please suggest.
Kind regards
Dheeraj van Voorde
(1) why don't we not create an odd number of voting record?
With regard to the vote of the disks are concerned, a node must be able to access exclusively more than half of the discs with the right to vote at any time. So if you want to be able to tolerate a failure of n disks to vote, you must have at least 2n + 1 configured. (n = 1 means 3 discs with voting rights). You can configure up to 32 drives with right to vote, providing protection against the 15 simultaneous disk failures.
Oracle recommends that customers use drives 3 or more with right to vote in Oracle RAC 10g Release 2. Note: For best availability, 3 files of voting should be separate physical disks. It is recommended to use an odd number as 4 drives will be more highly available than 3 disks, 3 1/2 is 1.5... rounded up to 2, 4 1/2 is 2, once we lose 2 discs, our cluster fails with 4 disks with voting rights or 3 discs with right to vote.
(2) only the cluster checks actually for the counting of the votes before node eviction? If so, could you expain this process briefly?
Yes. If you lose half or more than all your discs with right to vote, then nodes get evicted from the cluster, or nodes to expel from the cluster.
(3) what is the logic behind the documentaion note which says "each node must be able to see more than half the disks with right to vote at any time"?
The answer to the first question is will also answer this question.
answered by: Silva
Reference: Question on voting drive
Question on voting drive
Tags: Database
Similar Questions
-
Discs with voting rights are not visible in 11 GR 2 under ASM
Hi all
I had built a 11.2.0.3 new CAR configuration at 2 knots.
When I run crsctl query css votedisk - here is the list of discs with right to vote, but when I go to the spot using asmcmd, I am not able to see them.
Is there a particular reason for it / problem with my installation.
Thank you.Hello Sandeep
sandeep_dba wrote:
Is there a particular reason behind hide the file with the right to vote in ASM disk groups?hide? It is a strong word. Don't forget that asmcmd require an ASM instance to be operational. asmcmd is a convenience tool.
Disks with voting rights are accessible even before that ASM is available, as CSS is started before ASM by profile of negotiators. Thus, discs with voting rights are stored in a specific location in the ASM disk itself header area. Fritz blogged about this: http://fritshoogland.wordpress.com/2010/03/03/where-is-the-voting-disk-in-asm/
See you soon
Dominique caly
Blog: http://orainternals.wordpress.com/
Oracle ACE Director and OakTable Member http://www.oaktable.net
Fall 2012: [seminar advanced RAC | http://www.orainternals.com/services/training/advanced-rac-training/] -
How to recharge my hard drive with photos that are stored in iCloud? After installing a new hard drive, there's no pictures found in the Photos, and I get this error, "could not find the picture of system library named"Library.photoslibrary Photos".
Soon as your App Photos or iPhoto lost track of your photo library, or there has not been migrated from your old drive. You can create an empty library and probably enable iCloud photo library for photos to upload to the cloud.
-
I can't update photoshop and Lightroom... .quelquechose with administrator rights are required to update my product...
Rights administrator is a computer operating system message that says that you don't have permission to computer to do what you want
Do run as Administrator http://forums.adobe.com/thread/969395 [says again and also to Adobe all emissions] will sometimes fix permission errors
-
Question about adding additional disks with voting rights (AIX cluster)
I maintain a database cluster Oracle 10 g RAC running on AIX servers and I would like to add another disk to vote. I intend to use the following, executed command as root: crsctl add css votedisk device_pathname.
This command can be performed while the database and cluster services are active, or do I have to stop both before changing the configuration of the cluster?
Thanks in advance for any help!as stated in the doc:
* "" using the - force option while any cluster node is active can corrupt your configuration. "*"
MetaLink Note 428681.1 (updated Dec 2008) clearly said that the crs must be stop in 10 g on all nodes before making any changes on the drive to vote
-
Help with voting system (PHP)
I'm working on a voting system for my site, allowing users to rate presentations.
On the overview page, there is a counter with voting rights (1-5) that is in fact five individual images side by side. "Everyone connects the user to the same page (index.php? page = submission & id = [id]) but adds ' & vote = [a number 1-5]" to the url. When the page loads it checks if $_GET ['voting'] is set and will take measures accordingly. Once these actions have been performed, I wanted to use the function header PHP to reload the same page without the variable 'vote' in the url, but I can't do that because the presentation page is an inclusion on index.php, then he tells me that the header has already been set.
Of course, this method isn't going to work. Could someone tell me a better way to do this?I'm working on a voting system for my site, allowing users to rate presentations.
On the overview page, there is a counter with voting rights (1-5) that is in fact five individual images side by side. "Each one connects the user to the same page (index.php? page = submission & id = [id]) but adds ' & vote = [a number 1-5]" to the url. When the page loads it checks if $_GET ['voting'] is set and will take measures accordingly. Once these actions have been performed, I wanted to use the function header PHP to reload the same page without the variable 'vote' in the url, but I can't do that because the presentation page is an inclusion on index.php, then he tells me that the header has already been set.
Of course, this method isn't going to work. Could someone tell me a better way to do this?
-
Go to about: config and changed tabs on top for false but tabs are always on top.
Well, it is a bit of information that would have been helpful to forward. Enough criticism, wouldn't you say?
In any case, it worked, and I now have tabs on the bottom. Thank you.
And somebody had to hit Firefox developers who continue to take away the feature at the side of the head with a 2 x 4. Apparently, they won't have to 'do' another way.
-
Why my passwords are always deleted when I clear my cookies and history even when I leave the clear saved passwords box unchecked?
It happens whenever I have erase my cookies etc.
May be your unsaved preferences.
-
How can I reset my "authentication required" username and password? The fields are always filled with my old information.
Follow these steps to delete the recorded data (form) in a drop-down list:
- Click on the (empty) input field on the web page to open the drop-down list
- Select an entry in the drop-down list
- Press the DELETE key (on a Mac: shift + delete) to remove it.
- Tools > Options > Security: passwords: "saved passwords" > "show passwords".
You may need to clear cookies from this site, so if you checked a box to remember you.
-
Are there compatibility issues during the cloning of a HD with 32 MB Max for a max of 16 MB, or vice versa, HD the two 500 GB drives.
Thank you in anticipation.
Original title: cloning of hard drives with Max different buffers
Hi blacksmith60,
No, there is no problem with compatibility. But, you may notice a slight change in speed and performance.
-
T7500 does not start - there are virtual offline or missing drives with preserved cache
Dell 7500 PERC 6 / i controller, poweredge extended RAID with the device boot-SATA SSD and SATA RAID 1 data drives. A restart of an Acrobat patch system stops start after charges Poweredge and this error - ago offline or missing of the virtual drives with preserved cache, press a key to enter the configuration utility. In light of the not the choice I enter the configuration utility. Initially, the SSD has emerged as a foreign configuration but after several attempt to import the configuration, I decided clearly and followed an article on adding back as a RAID 0, but not initialize it, but that no longer works. Don't know if the drive is dead or what since I can't get out of BIOS. Always goes to the error. I guess I have to clear the preserved cache but do not want to lose the mirror. Posted the same problem yesterday, but he does not appear in the forum so I don't know if there is a filter or something. Need help - high-end system for FEA analysis and is necessary.
Thanks in advance
Figured it out. Dumped the cache on the controller and added back the lack of table, but it has not initialized. Change the boot device in the BIOS of the controller to the 'new' table; somehow the old VD1 became VD0 and re-added VD0 became VD1 and restarted. System came fine. No idea what caused it, but at least now it's back to work.
Concerning
-
Mr President.
When I convert a few changes on a page of its buttons on the right side of the page (> >) sings two more.
What is that this does not happen and the buttons are always visible?
Concerning
Did you try what I suggested?
listed AFStretchWidth styleclass property of panelGroupLayout and remove the box toolbar tools just use inside grouplayout
If this does not work please share your xml source
Thank you
-
Hello, now that I am back to my annual plan with payment each month creative programs cloud, made the payment came the confirmation, however downloading the programs are always identified as a test version, update this information?
allow 1 day working pst for your payment to process.
After this time, if there is still a problem, Troubleshooting FAQ: what should I do if I have a subscription, but my application acts as if I had a trial?
-
Hello
I work with the module development and when I change something with correction of the area I can't move to the next image with the right arrow.
Is there a solution?
Norbert
I think that Yes you are talking about "Spot healing.
So once you have used the tool, please click "Fertig" at the bottom right of the image.
Try, and then use the arrow keys.
-
I was told that CC versions of Photoshop, InDesign and Illustrator are available with support right to left languages flawlessly. Please order ME CC working with languages of the West and the Middle East. My problem, it sucks, I talked to Adobe can tell me how to order the ME version. I went around and for a week with them and have gotten nowhere. I can't believe I'm the first person to ask for this version of CC and hope someone on the forum can point me in the right direction. One last question - does anyone know how to reach support and talk to a real person? Thank you.
Hello
You will need to contact support by calling/chat for this request.
* Be sure to stay connected with your Adobe ID before accessing the link above *.
Kind regards
Sheena
Maybe you are looking for
-
OSX 10.5 Leopard installation problem
I tried to install OS x 10.5 Leopard on a new HDD in my door mirror, Power PC and OSX 10.5 Leopard installation disc is stuck in the installation screen, with the motionless progress bar and under saying "time remaining: calculating...» "on a new WD
-
everytime I turn on my HP Laser Jet 100 MFP175nw, I get a window on my PC that reads: you need to format a drive (see image). Not affect my impression, I just have to close the window, but it's annoying. Any advice?
-
Radio recorded covers of songs - legal?
I have recorded a bunch of songs on the radio with my rocket, replaced .wav .mp3 format, edited the songs (gave good titles, artists, albums, years, genres) and put them in the section music of the "rocket". First of all, I did it with Rhapsody. Ho
-
Good afternoon Is there a way to remove the time on a date cell using format? example: 11/01/2014 03:02 I have change the format so far, but when I put my cursor on the cell, it always displays the time. I have an automatic formula to get out of th
-
I have vista home Premium and have problems with desktop security 2010 unistallation.
3b44877b7f00c8b93588d9924cec7772 I tried to pass thru Panel etc and it proved futile. I continue to have three errors pop up and homepage of the trial Security Office running at a rate of duplication that I can't follow! Tried to ask for help through