A few basic questions about Proxmox, post install

TheePorkchopExpress

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Nov 26, 2021
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Hello everyone,

My apologies if this is a basic question(s) but I surfed Reddit and these forums and could not find what I was looking for...

Just installed Proxmox on a R620. On the R620 I had configured 2 VDISKs and RAID on the server.
  1. 2x 400gb HDs, in RAID1 for the install, OS (I plan on replacing these with SSDs after christmas)
  2. 6x 400gb HDs in RAID6
Note: If it matters, I am spinning up a second server and will create a cluster, but as of now it is just one server.
  1. I cannot figure out how to passthrough/bring those 6 drives in the 2nd VDISK (in RAID6) to install new VMs/Containers on (i.e. I want to see them in the GUI as an option). I have launched Proxmox, but expected to be able to install all the VMs on the drives in RAID6 including their data - was this a wrong assumption?
  2. LVM thin is my only option for install, should I see LVM? or just LVM thin?
  3. Do I need to configure something in Proxmox for the other VDisk?
  4. Would it just be easier if I scraped the RAID work on the server i already did, and get an HBA in IT mode, and use ZFS?
 

Dunuin

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Jun 30, 2020
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Hello everyone,

My apologies if this is a basic question(s) but I surfed Reddit and these forums and could not find what I was looking for...

Just installed Proxmox on a R620. On the R620 I had configured 2 VDISKs and RAID on the server.
  1. 2x 400gb HDs, in RAID1 for the install, OS (I plan on replacing these with SSDs after christmas)
  2. 6x 400gb HDs in RAID6
Note: If it matters, I am spinning up a second server and will create a cluster, but as of now it is just one server.
  1. I cannot figure out how to passthrough/bring those 6 drives in the 2nd VDISK (in RAID6) to install new VMs/Containers on (i.e. I want to see them in the GUI as an option). I have launched Proxmox, but expected to be able to install all the VMs on the drives in RAID6 including their data - was this a wrong assumption?
How did you create that raid6? I guess HW raid? In that case you should create a LVMthin storage ontop of that HW raid and use it as a VM storage.
  1. Would it just be easier if I scraped the RAID work on the server i already did, and get an HBA in IT mode, and use ZFS?
Depends if you want the ZFS features and if you got enough RAM.
 

TheePorkchopExpress

New Member
Nov 26, 2021
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How did you create that raid6? I guess HW raid? In that case you should create a LVMthin storage ontop of that HW raid and use it as a VM storage.

Yes HW raid.
Depends if you want the ZFS features and if you got enough RAM.

I have 96gbs in the R620 and when it's ready the R720 will have 192gb. I think that would be plenty but not sure what I gain/lose with ZFS otter than starting over (not that I've done much).
 

Huch

Active Member
Mar 28, 2021
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When using ZFS you should keep in
mind that PVE needs around 4GB RAM for each TB storage. So a 3TB RAIDz drive will require additional 12GB RAM (for example).
 

TheePorkchopExpress

New Member
Nov 26, 2021
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When using ZFS you should keep in
mind that PVE needs around 4GB RAM for each TB storage. So a 3TB RAIDz drive will require additional 12GB RAM (for example).

Oh I thought it was 1gb of ram per TB... that certainly changes things. I'll keep hardware raid for now! Thank you!
 

Dunuin

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Jun 30, 2020
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Oh I thought it was 1gb of ram per TB... that certainly changes things. I'll keep hardware raid for now! Thank you!
Jep, rule of thumb should be 4GB + 1GB RAM per 1 TB of raw storage or 4GB + 5TB RAM per 1 TB of raw storage if you want deduplication.
But i will also work with less RAM and the more RAM the better.
 

TheePorkchopExpress

New Member
Nov 26, 2021
12
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43
Jep, rule of thumb should be 4GB + 1GB RAM per 1 TB of raw storage or 4GB + 5TB RAM per 1 TB of raw storage if you want deduplication.
But i will also work with less RAM and the more RAM the better.
Thank you, very good to know. Glad I didn't do ZFS at this point. I am learning enough right now...
 

Dunuin

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Jun 30, 2020
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I think its about replacing HDDs with SSDs and not about the raid level. Wasted money to get SSDs for PVEs root disks if the existing HDDs are fast enough as long as guests aren't not stored on them too. Especially because you don't want to use consumer SSDs for that. Because without the powerloss protection of a expensive enterprise SSD you could corrupt your PVE installation on an power outage (search the forum for all the people who wonder why PVE won't boot anymore after an power outage...even with a ZFS mirror where both consumer SSDs corrupted at the same time).
 
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LnxBil

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Feb 21, 2015
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I think its about replacing HDDs with SSDs and not about the raid level. Wasted money to get SSDs for PVEs root disks if the existing HDDs are fast enough as long as guests aren't not stored on them too. Especially because you don't want to use consumer SSDs for that. Because without the powerloss protection of a expensive enterprise SSD you could corrupt your PVE installation on an power outage (search the forum for all the people who wonder why PVE won't boot anymore after an power outage...even with a ZFS mirror where both consumer SSDs corrupted at the same time).
what he said!
 

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