ZFS Config with 4 SSDs/4HDDs

[Scholledev]

Hey together,

so I'm still somewhat new to the server virtualization environment in general and Proxmox in specific.
I'm currently still in a preliminary testing phase but I would like to define some core aspects of the configuration for production usage.

My use case summarized:

• A mix of dev machines for testing, debugging and developing (not taxing at all).
• A setup for Atlassian JIRA together with Bitbucket, Confluence, Bamboo and Fisheye (not so sure about Crowd but we'll see that). For sure the most taxing ones although concurrent user numbers will be really low here.
• An instance of Redmine with more possible concurrent users although less daily usage to be expected (that's more like a side project in my free time).
• Some small web services (custom stuff, nothing taxing at all there).
• A Ghost blog on my own
• Probably some media storage (tough only pics then, no considerable amount of movies)

The following hardware is available for me:

• 1x Xeon 2630v4 -10x2,2GHz (second socket available but not used currently)
• 256GB REG ECC RAM
• 4x SSDs 1000GB (Consumer Crucial MX300)
• 4x HDDs 4000GB (2 WD, 2 Toshiba, Enterprise-SATA)
• There are no empty bays available in the current rack, I'm stuck to the number (although I could exchange the storage theoretically).

The importance of the data/the server is not extraordinarly - means, there's no big enterprise relying on it or something like that. However, reliability is still an important point

No my thought at setting up the filesystem is the following:

• Have ZFS as a filesystem because the HW is not physically available for me (replacing the HW controller might get difficult due to this in case of failure). And to take advantage of its additional features obviously.
• RAIDz2 for the OS with the SSDs
• On the SSD pool run high-performance applications (JIRA applications). These are also considered more important applications relatively to the others.
• RAID10 for the HDDs. I considered RAIDz2 for them also however I think performance will suffer at a later point. I'm currently running all my Atlassian applications on a (relatively performant) VPS that's backed by pure SSDs, so I'm not sure how Redmine would do with that in a RAIDz2.
• Run more general VMs on the HDDs. Stuff stored there is considered less important compared to the SSD pool - Most test VMs will get reset regularly anyway (taking separate backups offsite and on FTP during config changes).
• Storage should not be an issue in the forseeable future by any means. I'm already planning in a way that I should not use more than 4TB over the timeframe of the next 5 years (for the HDD pool, for the SSDs not more than 2TB).

So, does this plan sound reasonable? I'm not sure about the HDD pool, I would bit limited to the read speed of a single device as far as I read.

Open for thoughts.

Greetings Marcus

 

[pabernethy]

All Proxmox VE versions does not support the Linux Software RAID (mdraid). That means, its not tested in our labs and its not recommended, but its still used by experience users. If you want to run a supported configuration, go for Hardware RAID.

If you were going for hardware RAID anyway, great.
I don't see why Redmine would not be happy in a RAIDz2. ZFS relies heavily on caching and will happily gobble up any and all RAM that you assign to its ARC. So if you suspect Redmine to be by far the most active VM on the HDDs you could determine how big its database is and make the ARC larger. This way the DB should always live in memory. And with LZ4 compression enabled you can even squeeze out some extra storage.
Also what makes you think performance will decrease in a RAIDz2?

 

[Scholledev]

Also what makes you think performance will decrease in a RAIDz2?

Thanks for your insight.
Actually, the comment about a potential performance decrease was meant in comparison to RAID10. But with the available RAM I'll most likely go with RAIDz2 then to take the better redundancy.