managin different disk sizes with ceph

[benoitc]

We have a cluster of 3 machines that have 2x460GB SSD HD on each and we plan to add 2x960GB to each. AT first we were thinking to just replace the 480GB disks but now I am wondering if we can mix disks from different size.


How will work the replication in such case? What's the best pattern for it?

 

[Alwin]

How will work the replication in such case? What's the best pattern for it?

Keep them evenly distributed. Ceph will use different ratios for those disks and fill them accordingly.

 

[benoitc]

Keep them evenly distributed. Ceph will use different ratios for those disks and fill them accordingly.

so i just need to add the 2 disks on eahc machines and it wil be good? ie having 2x480+2x960 on each ? That's pretty cool

 

[Alwin]

To add, in any case (as always) you will need to keep an eye on the usage.

 

[benoitc]

so i just need to add the 2 disks on eahc machines and it wil be good? ie having 2x480+2x960 on each ? That's pretty cool

indeed. Thanks for the hint!

 

[rafafell]

Hello @benoitc , I'm starting to implement CEPH here. Could you please report whether this arrangement of yours was successful. did it meet your needs?