Xcp-ng Storage Configuration

Prodatalink · March 26, 2020, 10:47pm

I have a server with 5 - 2TB drives and 3 - 3TB drives. What’s the best way to configure the storage for xcp-ng? I was thinking of doing RAID 5 with the 2TB and RAID 0 with the 3TB or is it not a good idea to mix drive sizes?

FredFerrell · March 27, 2020, 1:54am

Personally, I would never use RAID0. I think RAID5 is fine for the 2TB drives, but RAID6 would be better. You’ll have to use RAID 5 for your 3TB drives since you only have three of them. Since all the drives are the same size in each array you won’t have any issues.

LTS_Tom · March 27, 2020, 3:26pm

Create separate raid pools for each group of similar drives, but don’t use raid 0 unless you just doing testing. Raid 0 will give you the most space at the highest risk or failure because if any one drive dies it will take the array with it.

Prodatalink · March 28, 2020, 2:01am

Thanks for the advice!

itoutfitters · February 8, 2021, 10:14pm

Does anyone know of some simple instructions for setting up RAID on xcp-ng, particularly having storage RAID (even mirror) separate from the boot partition? (I understand creating a RAID during installation is possible for the system drive(s)).

The idea would be to have a small RAID 1 for the system, and then a larger RAID 1 or 5 for storage.

TIA

LTS_Tom · February 9, 2021, 10:04am

You could use ZFS Storage in XCP-ng | XCP-ng documentation

itoutfitters · February 11, 2021, 5:42am

I really like using zfs at least in my storage systems (nexenta and now TrueNas), but there was a warning in that documentation you linked to suggesting:

WARNING

Note: If you use ZFS, assign at least 16GB RAM to avoid swapping. ZFS (in standard configuration) uses half the Dom0 RAM as cache!

I know that many people run with relatively high RAM these days, but in my case the system will have 16G and 32 if needed. I run several ESXI servers with 16 G of RAM and they perform very well for my Lab work - so I am concerned with that warning… NFS or EXT appear to both support thin provisioning and efficient storage without the warning about eating RAM for swap.

Question: In that scenario is the warning a valid concern? If so, then which would be the next best go to for local machine storage?

Keith

LTS_Tom · February 11, 2021, 10:51am

linux mdadm raid setup.

itoutfitters · February 26, 2021, 12:30am

Here is a good step by step for using the CLI to list drive details and subsequently create a RAID and set it up to be a Storage Repository (SR):

note even though it states here to not create a repository during installation, somehow I had inadvertently set this up when I started the XO web based wizard but cancelled. It still worked.
** the only options covered in this guide was to create EXT or LVM - I chose EXT.

Keith