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p

proud-addition-21854

11/18/2022, 3:29 PM
Longhorn question. On harvester nodes, do we add muitlple disks by “Add Disk” or do we add a Raided single disk?
f

full-plastic-79795

11/21/2022, 2:23 AM
Both should work, but I'm not sure which is the best practice for longhorn. There are many things to consider: performance, security, and ease of operation and maintenance. I created an issue on github https://github.com/harvester/harvester/issues/3183 to track this and get advice from longhorn experts
p

proud-addition-21854

11/21/2022, 3:23 PM
Say if you have two 100GB disks on each node. They both mounts as seperate extra disks. Now when I upload an image 125GB, it fails saying “No space left”. How do we handle images larger than a size of a single disk?
f

full-plastic-79795

11/21/2022, 3:27 PM
In this case, it seem that the only option is to increase the size of the hard drive, either by using multiple hard drives for RAID or by using a larger single hard drive
p

proud-addition-21854

11/21/2022, 3:28 PM
Hmm ok. How about creating a virtual machine or a volume larger than 100GB? Have not tried yet but what is going to happen?
f

full-plastic-79795

11/21/2022, 3:31 PM
longhorn replica can't be scheduled because there are no disks have enough space
p

proud-addition-21854

11/21/2022, 3:41 PM
Say I have , 3 nodes. each with 2x 100GB disks
The VM i am creating is 125Gb in size
f

full-plastic-79795

11/21/2022, 3:47 PM
Oh, sorry. I forgot that longhorn storage can be overcommit, since the default storage overcommit setting is 200%. I guest it will success. https://docs.harvesterhci.io/v1.1/advanced/settings#overcommit-config
p

proud-addition-21854

11/21/2022, 3:50 PM
May be I am asking too much , but how about if you need a thick provisioned vm?
f

full-plastic-79795

11/21/2022, 3:53 PM
What do you mean
a thick provisioned vm
? the example vm with 125G disk?
p

proud-addition-21854

11/21/2022, 3:54 PM
RIght. I mean nonsparse or preallocated disk volume
f

full-plastic-79795

11/21/2022, 3:58 PM
Maybe I will use
qemu-img
to shrink vm image first
p

proud-addition-21854

11/21/2022, 4:02 PM
The image is a qemu-img converted image and it took down to 125GB from 275GB.
f

full-plastic-79795

11/21/2022, 4:05 PM
The vm is successfully created in favor of storage overcommit.
p

proud-addition-21854

11/21/2022, 4:06 PM
Ok
Thank you. I will test it when I can and report here
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