Using ZFS with MBR (cannot use GPT...)

[hakim]

Hi,

In the page Storage: ZFS, it is mentionned 2 times : "(important: use GPT partition table)"

Unfortunately, I am using a server that is alredy pre-installed with Proxmox4, but on an MBR partionned disk, and I cannot change it.
I manage to create extra-partitions on that disk in order to create a Zpool to use on Proxmox.
Do you think that I might face problems going that way ?
And if so, what kind of problems ?

Thanks,
Hakim

 

[fireon]

You can't change the existing installation... you can but an new install on ZFS is easier. But you can add a few this to your server on an extra new pool. That is easy. Put the disks in, for example 4 disks for Raid10 and do an zpool. With one command everything is done.

zpool create -f -o ashift=12 <pool-name> mirror <device1> <device2> mirror <device3> <device4>

 

[hakim]

Hi,

Thanks for your answer. But my problem is a bit different.

I have a server with an existing disk (already installed, using MBR). I cannot add any new disk, and therefore my question is about : if I add on this existing disk :
- a partition for the data (MBR / primary)
- a partition for the logs (MBR / logical - not enough primary partitions...)
and create a zpool with these two partitions (which I already did, and so far it seems to be working), may I expect problems because it is based on MBR ?

Thanks,
Hakim

 

[fireon]

Hi,

Thanks for your answer. But my problem is a bit different.

I have a server with an existing disk (already installed, using MBR). I cannot add any new disk, and therefore my question is about : if I add on this existing disk :
- a partition for the data (MBR / primary)
- a partition for the logs (MBR / logical - not enough primary partitions...)
and create a zpool with these two partitions (which I already did, and so far it seems to be working), may I expect problems because it is based on MBR ?

Thanks,
Hakim

I don't really know this, but yes ZFS does work also on Partition. Recommended the whole disk. Maybe ZFS works also on MBR. Better you test it with an other machine.

 

[hakim]

>> Better you test it with an other machine.

I already did a test and I can create VMs, and do some little things...

But, I would prefer to get a feedback from either the Proxmox team, or any people using such a config before going in prod and discover that for some reason, this is not reliable.
I did some search and could not find another place with the statement writen by the Proxmox team : "(important: use GPT partition table)" ,
What are the kind of problems to be expected : performance issue, security issue, crash... ?

Thanks,
Hakim

 

[hakim]

Any chance to get an answer ?

Thanks

 

[fireon]

Any chance to get an answer ?

Thanks

Maybe you should open an supportticket.

 

[tom]

Any chance to get an answer ?

Thanks

You already got an answer, more or less all is said.

 

[hakim]

Hi Tom,

>> You already got an answer, more or less all is said.

Well in fact, I got an answer, but not to my question which is about the Proxmox statement about GPT partition table (see below) :

I did some search and could not find another place with the statement writen by the Proxmox team : "(important: use GPT partition table)"
What are the kind of problems to be expected : performance issue, security issue, crash... ?​

This is why I was expecting to have another answer...

Best regards,
Hakim