Question about minfree, maxroot, swapsize and ext3 / ext4

[FcbInfo]

I have some doubts about this values?

What is the recommended values for:

maxroot = XX
This will be only used by the system root?
We will need some space in partition in the future?
Temporary lzop files for backups is stored here?

swapsize = XX
This really need to be the same value of our installed memory or we can go for a lower value?
Ex: I have a server with 32GB of ram, but my first hdd is a SSD of 128, i really need to waste 32gb with swap space?

minfree = XX (sets the amount of free space to remain on the disk after the Proxmox installation).
For what this will be used?
I don't know how much space is the best option for me.
At my last installation, I used "minfree = 1"

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And another question is about the EXT3 and EXT4.

Many peoples and many sites, always says that EXT4 is much better than EXT3, but on the proxmox wiki we read this: https://pve.proxmox.com/wiki/Install_Proxmox_VE_on_Debian_Wheezy

"We recommend to use ext3 filesystem for best OpenVZ performance and stability."

What is the real best option?

Thank you guys for the help. If Udo comes here, I believe that will be the best reply =P.

 

[wahmed]

Unless you are using very large file system say 32+TB or working with single virtual disk image of 2+TB, there are really no real definite reason to use ext4 over ext3 or vice versa. Ext3 of course if very very mature due to how long it has been out. Ext4 also dont have much report of failure. But personally i find ext3 slightly faster than ext4.

Basically:
Ext3=Supports 02TB to 32TB overall file system, max. single file size supports 16GB to 02TB, max. directories 32,000.
Ext4=Supports 02TB to 01PB overall file system, max. single file size supports 16GB to 16TB, max. directories 64,000, journaling can be turned off.

I myself use ext4 for very mission critical nodes/vm.

 

[mir]

Three more things to add in:
1) EXT4 is an order of magnitude faster for filesystem check
2) The journal in EXT4 uses checksums
3) EXT3 does not support SSD's so Wear leveling will destroy your SSD's faster on EXT3

 

[udo]

I have some doubts about this values?

What is the recommended values for:

maxroot = XX
This will be only used by the system root?
We will need some space in partition in the future?
Temporary lzop files for backups is stored here?

swapsize = XX
This really need to be the same value of our installed memory or we can go for a lower value?
Ex: I have a server with 32GB of ram, but my first hdd is a SSD of 128, i really need to waste 32gb with swap space?

minfree = XX (sets the amount of free space to remain on the disk after the Proxmox installation).
For what this will be used?
I don't know how much space is the best option for me.
At my last installation, I used "minfree = 1"

Hi,
depends on your config.
I have good experiences with maxroot=20 and swapsize=8 (or 4 - if your server begins to swap there is something wrong). But if you use the root also for backups the 20GB are much to less.

minfree can be helpfull for lvm-snapshots.

Udo

 

[wahmed]

Three more things to add in:
3) EXT3 does not support SSD's so Wear leveling will destroy your SSD's faster on EXT3

Very good point!!

 

[FcbInfo]

Oks... Thank you guys for the help.

 

[kimismenos]

minfree can be helpfull for lvm-snapshots.

Hi there,

I know this is thread is old, but i'm confused. How exactly can it be helpfull with snapshots?

I thought snapshots where a feature of the filesystem itself and woulde hence be stored in the exact same logical volume in which the corresponding vm/ct lifes.

I dont know about the OPs config, but I have a 237.5gb partition with a physical volume of 205.5gb, a volume group of 205.5gb (allocated) and 32gb free space (PFree/VFree).

I' mean it's not unallocated space on my drive that I could turn into a partition. It's already part of the partition, but the filesystem does not use it.

How can I use this free space apart from extending the physical/logical volume(s)?