New home server setup need advice.

[vl1969]

Hello, I have been playing with some different vm, fike server setup for a while. Finally I think I zero onto setup I want, as in CentOS 7 with kvm, managed via webmin and cloudmin or convirt.

My question though is about system setup.

Is it worth to do a system on raid 1 ?
I have been trying to do a full system setup on a bootable software raid1 and so far not fully successful. I mean if I go through all the trouble setting up on raided drives I want them to boot from either one. If one fails second should boot up in degraded mode but still run.

Also is it worth to setup a home set it and foget it server using sdd for system. It will run pretty much 24/7
With only occasional reboot.
I have a couple ssd drives 120gb that I can spare for this, but I can also use them somewere else.

Please advise.

Thanks Vlad

 

[pricklypunter]

More information on your setup is required for any meaningful answers. To begin with, are you using hardware or software raid etc? What other hardware do you plan in your build? What are your goals here?

My own feelings for using raid OS drives is that about the only real benefits I see would be down time reduction and perhaps a little speed advantage. The other side of that coin is more administration and higher cost. For a heavy database server, the extra speed might be an advantage. If it is also located remotely, then having that redundancy is a plus point. If it is a production server where there are downtime penalties involved, then the redundancy, if properly set up, gives you the opportunity to deal with the issue without disrupting the client. Of course raid will not protect you from yourself, if you delete something accidentally for example, mis-configure your OS or have any kind of filesystem corruption you will mirror that onto the other disks and you may not be able to boot the server anyway.

For home use, where I have full and easy access to my server, I see little benefit of using raid for an OS disk, it only complicates my setup and recovery should the worst happen. My first stop would be a recent backup then either a cloned disk sitting on the shelf, or as a last resort, a recent image file on a DVD or pen drive would be the way I would go. I can live with the downtime of the half hour while I either restore my backup, swap the disk out or re-image etc.

Using an SSD for the OS will bring obvious benefits, and you could probably reduce your costs a little by going for something read optimised with medium endurance, but for home use, raid used for an OS is hardly worth the trouble imho

 

[Jeggs101]

You need to setup mdadm RAID 1 during installation. I still do RAID 1 boot drives just because it sucks to have to fix them.

 

[vl1969]

Ok, let me clarify few points here.

1. This is a home server. Will be used as a file server for whole household and media file server.
Also a virtualisation server using kvm

2. I do not have hardware raid. So if decided will use software raid.

3. I am thinking about using raid for system drive so I do not have to redo whole setup if drive fails. Do you think it would be simpler to image the drive after every update or change?

4. I am thinking of using ssd simply because I already have then, it might be less power hungry than hdd

 

[pricklypunter]

While raid has some benefits, it's not the holy grail and as I mentioned earlier, it won't save you from yourself, that's what your backups are for. Software raid is a good choice, if for no other reason than it is largely hardware independent, so a failed mainboard or controller is little hindrance to getting up and running again, however, this is a home setup and not a production server with an SLA, and for the reasons I already touched on, I personally wouldn't bother with the complexity of raid for the OS drive on a home server. Think for a minute about what is involved in the event of a raid disk failure, and what would be required to fully restore it. Compare that same scenario having a single OS disk and either using a backup, cloned drive or an image file. Really there isn't much difference time wise, if anything re-imaging a corrupt disk is actually quicker, and a lot less complicated than fixing a bad raid array. As for still allowing you to boot on a degraded array, that only works in practise if the filesystem left on the good disks hasn't been corrupted by the failed one prior to it going offline. If it has been, you are back to square one with a non bootable OS anyway. Using an SSD for the OS has some benefits, speed being an obvious one, power for another and noise level, but depending on what you are planning, it may not be necessary. Lots of hypervisors commonly boot from SD cards or USB pen drives nowadays because it is loaded directly to RAM and runs from there, so there is no real speed advantage of using SSD for example

 

[Biren78]

Ok, let me clarify few points here.

1. This is a home server. Will be used as a file server for whole household and media file server.
Also a virtualisation server using kvm

2. I do not have hardware raid. So if decided will use software raid.

3. I am thinking about using raid for system drive so I do not have to redo whole setup if drive fails. Do you think it would be simpler to image the drive after every update or change?

4. I am thinking of using ssd simply because I already have then, it might be less power hungry than hdd

1 - Great - you game to the right place
2 - Most of us here are probably in the same, SW RAID
3 - If you are going to keep the same base OS, and it looks like you're using inexpensive enough SSDs, just do RAID 1 mirror.
4 - Yes and they make less noise at home

 

[vl1969]

1 - Great - you game to the right place
2 - Most of us here are probably in the same, SW RAID
3 - If you are going to keep the same base OS, and it looks like you're using inexpensive enough SSDs, just do RAID 1 mirror.
4 - Yes and they make less noise at home

Noise is not an issue. I am running this server now with 10 hdd, it barely make any noise to speak off.

What do you mean by "if I am using the same base os" ?
My plan is to setup a centos 7 with kvm for host. Install webmin and cloudmin or convirt for host and vm management. Do a nfs shares for all data drives
And provide storage acces via openmediavault vm.

 

[Biren78]

Noise is not an issue. I am running this server now with 10 hdd, it barely make any noise to speak off.

What do you mean by "if I am using the same base os" ?
My plan is to setup a centos 7 with kvm for host. Install webmin and cloudmin or convirt for host and vm management. Do a nfs shares for all data drives
And provide storage acces via openmediavault vm.

Responding to: "Do you think it would be simpler to image the drive after every update or change?" if you keep using CentOS, RAID 1 is easier. If your updates or changes would be to switch to Debian, then that's different.

Sounds like what you have will work. I know many of us have switched to Proxmox. I'd like to see how your cloudmin turns out for you. You should make a new thread when you get it setup to share.

 

[vl1969]

Once all is setuped and works to my satisfaction I am not planning to switch distro. I see no ppont in doing this.
and of course if I decide later that I want to go with another os, raid will not help me but by than I would simply grab a spare drive and setup on it.

I would love to run proxmox, however the base setup does not support btrfs, and if I want to use btrfs, and I do, I have to do a Debian/proxmox install. It adds complexity and still does not work as I want it to. So I figure if I have to go through all this steps I might as well do a straight up install on a regular distribution. Adding only what I really need or want to it.
Centos supports thing I want out of the box except for web ui.
But webmin gives me that.
Add a cloudmin or convirt, and I got a web ui for vm management as well.

All this is nice exercise on learning Linux and networking and virtualization.