how can devide one disk between 3 datastore

[baber]

dear all

hi

i have a question about increase datatstore i have installe esxi 5.5 U3  and have 3 datastore all of my datastore have 3Gig free space now i have added new physical disk (300G) to my server  and create raid 0 now i want to knoe how can devide this disk between  3 datatstore for example add 90Gig to each of my datastore now i have right cklick on one of my datastore and click properties then select increase and select (300G) disk and in customize size fill with 90G and 90G added to my first datastore then do all these steps on datatstore2 but when i click on increase it did not show any disk

how can solve the problem?

Best regards

Babak

[continuum]

Never ever use raid0 for a VMFS-datastore - thats a suicide-mission !!!

[SebastianGrugel]

If i good undersrood  you use for Creating raid-0 your new disk 300GB and your Old disk?  Or Old disk you not touch?  and you Creating raid-0?  ony from your new disk? I know that it does not make sense but I would like to understand the question 🙂

[Madmax01]

Hi baber,

as continuum pointed > in an Productiv Environment it's not recommended to use a Raid-0.  if you want to have you're Data reliable available in a Fault Case, then you need a Minimum of Raid-1. Better is Raid5. Even in Lab Environment you should know that you loosing Data with Raid-0.

also i wouldn't use vmfs extents. As if the HW behind not supporting an Nativ increase > then you doing a Chain. like a Stripe. means then you're datastores could go offline in Worst Case.  vmfs5 handling it more better, but anyway could go offline.

So would be good to think about moving data away, and to re/create Raid from Scratch.  If you like more Performance with non-ssd > you could check for Write-back with BBU. More better instead of using Raid-0 .  

Best regards

Max

[continuum]

We continued the discussion via skype-chat.
We discussed options to split vmdks over 3 datastores but I tried to explain why I highly recommend against doing so.
By the way - my experience with VMFS volumes using Raid 5 is as follows:
Customer: I have an issue with a raid5 rebuild - my datastore looks empty. Can you help to recover my data ?
Me: Oh dear - dont use raid 5 for VMFS-volumes. Lets see anyway - sometimes recovery is possible ....

[Madmax01]

Ha .  i know. Even Raid-1/5/6 and up are not 100% reliable if Controller issuing or too much Disks failing.  a good Backup or DR needs to have in Place anyway

[continuum]

I have no reasons to warn if Raid1 or 10 is used.

[baber]

thanks

but could not undestand correctly can esxi do this:

can add new disk and use from this disk for increase the space of other datastores ?

for example if new disk is 800G devide that to 3*200G and add each 200G for increase one of datastores?

Best regards

Babak