Share a persistent disk between Google Compute Engine VMs -

-

from google's documentation:

it possible attach persistent disk more 1 instance. however, if attach persistent disk multiple instances, instances must attach persistent disk in read-only mode. not possible attach persistent disk multiple instances in read-write mode.

if attach persistent disk in read-write mode , try attach disk subsequent instances, google compute engine returns error.

so, need have share persistent-disk frontend compute engine, good, how can write on shared disk?

my guess (i hope) a read/write persistent-disk can attached 1 compute engine same disk can share in read others vms, thats right?

lets have 2 compute engine vms , 2 persistent disks, flow possible?

  • compute1 read/write disk1 , read disk2
  • compute2 read/write disk2 , read disk1

no, not possible, documentation cited @ time of writing said (since updated):

however, if attach persistent disk multiple instances, instances must attach persistent disk in read-only mode.

the documentation has been re-arranged since then; new docs @ different url same content:

you can attach non-root persistent disk more 1 virtual machine instance in read-only mode, allows share static data between multiple instances. sharing static data between multiple instances 1 persistent disk cheaper replicating data unique disks individual instances.

if attach persistent disk multiple instances, of instances must attach persistent disk in read-only mode. not possible attach persistent disk multiple instances in read-write mode. if need share dynamic storage space between multiple instances, connect instances cloud storage or create network file server.

if have persistent disk data want share between multiple instances, detach read-write instances , attach 1 or more instances in read-only mode.

which means cannot have 1 instance have write access while has read-only access.

if want share data between them, need use other persistent disk. below possible solutions.

you can use of following hosted/managed services:

alternatively, can run own:

  • database (whether sql or nosql)
  • distributed filesystem such ceph, glusterfs, orangefs, zfs, etc.
  • file server such nfs or samba
  • single vm data storage node, , use sshfs create fuse mount other vms want access data

Comments

Post a Comment

Popular posts from this blog

c++ - QTextObjectInterface with Qml TextEdit (QQuickTextEdit) -

-
i registred handler simple qtextobjectinterface , draws 10x10 red rectangle. when used qtextedit in normal qwidget app, worked. when used qquicktextedit (textedit qml component) in qt quick app, doesn't worked (nothing drawed, rectangle in textedit reserved, because when change cursor position, notice there something, empty space, nothing drawed. qtextobjectinterface intrinsicsize method called (that explains why see there empty space 10x10), drawobject method isn't. i did research , found problem here: qquicktextedit.cpp qt 5.3.0 sources (line 1821) qsgnode *qquicktextedit::updatepaintnode(qsgnode *oldnode, updatepaintnodedata *updatepaintnodedata) { . . . if (textframe->firstposition() > textframe->lastposition() && textframe->frameformat().position() != qtextframeformat::inflow) { updatenodetransform(node, d->document->documentlayout()->frameboundingrect(textframe).topleft()); c...
Read more

javascript - angular ng-required radio button not toggling required off in firefox 33, OK in chrome -

-
i trying toggle required attribute on radio button using angular show html5 popup. i cannot following code function correctly in firefox 33. function correctly in chrome. required property being toggled via checkbox value, in firefox, when set false radio button still acts required , shows html5 required popup. see plnkr below example doesn't work me in ff 33. <!doctype html> <html> <head> <script data-require="angular.js@*" data-semver="1.3.1" src="//code.angularjs.org/1.3.1/angular.js"></script> <link href="style.css" rel="stylesheet" /> <script src="script.js"></script> </head> <body ng-app="myapp"> <script> angular.module('myapp',[]) .controller('mycontroller',['$scope',function($scope) { $scope.foorequired=true; $scope.submitform = function() { $scope.submitmessage = ...
Read more

xcode - Swift Playground - Files are not readable -

-
Image
files not readable in swift playground . how make files readable? same code runs on xcode terminal app, fails on swift playground. demo code below. import foundation println("hello, world!") var fname:string = "/users/holyfield/desktop/com.apple.iconcomposer.plist" var fm:nsfilemanager = nsfilemanager.defaultmanager() if(fm.fileexistsatpath(fname)){ println("file exists") if(fm.isreadablefileatpath(fname)){ println("file readable") var fd:nsdata? = nsdata(contentsoffile: fname) println(fd?.length) let pl = nsdictionary(contentsoffile: fname) println(pl?.count) println(pl?.allkeys) }else{ println("file not readable") } } else{ println("file not exists") } sample images: i have thank nate cook first quick response , solid answer. just case share answer post, title misleading. see nate's answer here: https://stackoverf...
Read more