Thank you to everyone who went with me on this journey. For me it was
extremely fruitful. I was thinking a vCPU was a thread and therefore
one would need lots of cores and threads to make a Proxmox server. I
can not see that is not the case.
Based on all you good folks have tough me, I assume, I would be able to
use a 10 year old laptop with and i3-2130 CPU and maybe 8GB of RAM as a
Proxmox server for simple PHP development. Maybe even as little as 4GB
of RAM.
I also assume that with this machine (8GB RAM version) I would be able
to create a Web server configured running Proxmox and multiple VMs that
would all be running simultaneously, one for HTTP(s), one running MySQL,
one running BIND, and one running Dovecot and Postfix.
Understanding what a vCPU is really is a game changer.
Keith
On 2023-07-21 09:32, Ryan Petris wrote:
>> 1) a vCPU is akin to a process.
>
> Yes
>
>> 2) One can configure lots of VMs that will share the CPUs.
>
> Yes
>
>> 3) Do not overload the server by adding too many VMs that all want
>>
>> resources. I assume top can be used to evaluate the amount of load
>> on
>>
>> the server.
>
> That's correct, you should see one "/usr/bin/kvm" process per vcpu if
> you're using proxmox
>
>> 3) When I configure a VM the amount of RAM is static (not shared).
>> If I
>>
>> have 16GB of RAM then I realistically can only have around 12 - 14GB
>> of
>>
>> RAM in use at any given time. That would be running VMs. I can
>> have
>>
>> tons of VMs that are not running and not using resources/RAM and
>> their
>>
>> RAM is no counted. Its the active VM's that count. RAM is not
>> shared.
>
> The RAM _can_ be shared but that's dependent on the virtual machine
> being configured properly. Linux, at least, automatically detects if
> it's running in a virtual machine and enables what's called
> "ballooning" to give back unused ram to the host. So again, as long as
> you're able to keep the in use memory under your total memory you
> should be fine.
>
> A good rule of thumb though is, under normal load/usage, your in use
> memory shouldn't exceed 50% of your total memory.
>
> If you're going to run a Windows VM you'll want to make sure to
> install the virtio drivers, of which Fedora provides a compiled
> version of:
> https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/archive-virtio/virtio-win-0.1.229-1/
>
>> 4) The amount of file space allotted to a VM is also static and is
>> taken
>>
>> up even when the VM is off. For example if I have 10 VMs that are
>>
>> assigned 20GB of disk space each, then that would total 200GB that
>> are
>>
>> allocated and are always assigned and not shared with the other VMs.
>
> Disk space is also tricky, you can either pre-allocate it, in which
> case you're correct, or use "thin provisioning", where the VM will
> only take up as much space on the host as used in the VM. Now, that
> space will grow over time but will never shrink on its own, even if
> you delete stuff from the VM. If you think of it as an SSD that needs
> a periodic trim, it functions similarly. Coincidentally, if you use
> Proxmox with either "raw" disk images or use ZFS, then you'll be able
> to issue a trim command from the guest, which will release any unused
> disk space back to the host. I personally run a trim on all my VMs
> once every few months or so, or when I notice that a VM is taking up
> much more space than is actually in-use in the VM.
>
> You'll probably find some information saying that pre-allocating disk
> space is better because it performs better, however I think that
> advice is outdated especially if you're going to run the VMs on a good
> quality SSD or NVME drive.
>
> On Fri, Jul 21, 2023, at 8:02 AM, Keith Smith via PLUG-discuss wrote:
>
>> On 2023-07-20 16:25, Todd Cole via PLUG-discuss wrote:
>>
>>> I use a lot of proxmox servers and very happy with them most are
>> for
>>
>>> small office use running a router, win server and samba file
>> server
>>
>>> and a win 10 for remote users to vpn into
>>
>>> most of the hardware is used dell 4-6th gen I-7 (cheap 4 cores 8
>>
>>> virtual) with zfs raid 1 2 SSD's for redundancy and a spinner HDD
>> for
>>
>>> back up 32-64 gb ram and meet my needs
>>
>>> with ease. both at home and work.
>>
>>>
>>
>>> I have used rack servers but they are hard to fit on a shelf, HOT
>> and
>>
>>> use a lot of power and sound like a jet taking off. (I have a few
>> to
>>
>>> donate free)
>>
>>> my point is do not over think or spend money to build a home lab
>> or
>>
>>> hardware that you will need to replace due to your use case.
>>
>>> I still have one on a duel core 8 gb ram 2 250GB spinning disks
>> that I
>>
>>> use as a router and zoneminder camera DVR in a un air conditioned
>>
>>> vacant office it just chugs along in 118 heat
>>
>>> I have a twin to it that is all set up ready to run that I would
>> be
>>
>>> willing donate also. Todd
>>
>>>
>>
>> ---
>>
>> I'm starting to understand what a vCPU is and that I really do not
>> need
>>
>> a bunch of cores and threads. I have an old Dell i5 with 4 cores, 4
>>
>>
>> threads, 16GB of RAM, and a 1TB SSD.
>>
>> I'm a PHP developer and use the Proxmox box for testing and
>> development.
>>
>> Currently I have one LAMP VM configured.
>>
>> This is what I come away with from this thread:
>>
>> 1) a vCPU is akin to a process.
>>
>> 2) One can configure lots of VMs that will share the CPUs.
>>
>> 3) Do not overload the server by adding too many VMs that all want
>>
>> resources. I assume top can be used to evaluate the amount of load
>> on
>>
>> the server.
>>
>> 3) When I configure a VM the amount of RAM is static (not shared).
>> If I
>>
>> have 16GB of RAM then I realistically can only have around 12 - 14GB
>> of
>>
>> RAM in use at any given time. That would be running VMs. I can
>> have
>>
>> tons of VMs that are not running and not using resources/RAM and
>> their
>>
>> RAM is no counted. Its the active VM's that count. RAM is not
>> shared.
>>
>> 4) The amount of file space allotted to a VM is also static and is
>> taken
>>
>> up even when the VM is off. For example if I have 10 VMs that are
>>
>> assigned 20GB of disk space each, then that would total 200GB that
>> are
>>
>> allocated and are always assigned and not shared with the other VMs.
>>
>> ---
>>
>> OK, another question. If commercial rack mount servers are so noisy
>> and
>>
>> use a lot of electricity... then why not use consumer grade
>> computers?
>>
>> Around 2005/2006 I was working as a level 1 at iPower. A manager
>> showed
>>
>> us some pictures of the server room in downtown L.A. and they had a
>> ton
>>
>> of HP mini towers on storage racks that were being used as hardware
>>
>> servers for hosting. I think they called them dedicated servers.
>>
>> ---
>>
>>> On Thu, Jul 20, 2023 at 3:09 PM George Toft via PLUG-discuss
>>
>>> <plug-discuss@lists.phxlinux.org> wrote:
>>
>>>
>>
>>>> Be very careful with ESX. I know someone who bought a random
>> server
>>
>>>> and ESX7 was not supported. It used to run on anything, now, not
>> so
>>
>>>> much. Check the support matrix before you buy.
>>
>>>>
>>
>>>> Regards,
>>
>>>>
>>
>>>> George Toft
>>
>>>>
>>
>>>> On 7/20/2023 1:12 PM, greg zegan via PLUG-discuss wrote:
>>
>>>>
>>
>>>>> Hello,
>>
>>>>> I appreciate this topic. I have been wondering for a while now
>>
>>>>> if there is an affordable home server out there for EXSi and
>> such.
>>
>>>>> Is there any way for someone to come up with a few choices for
>>
>>>>> people like me? Is there a low end, mid range, and high end
>> home
>>
>>>>> server for someone to list with parts or suggested parts?
>>
>>>>>
>>
>>>>> thanks,
>>
>>>>> Greg
>>
>>>>>
>>
>>>>> On Thursday, July 20, 2023 at 01:01:13 PM MST, Keith Smith via
>>
>>>>> PLUG-discuss <plug-discuss@lists.phxlinux.org> wrote:
>>
>>>>>
>>
>>>>> Thanks!!
>>
>>>>>
>>
>>>>> On 2023-07-20 11:36, Ryan Petris via PLUG-discuss wrote:
>>
>>>>>> I personally wouldn't even go for a used server. They're
>>
>>>>> generally
>>
>>>>>> loud, and even when they aren't they use much more electricity
>>
>>>>> than
>>
>>>>>> what you would get from a consumer platform. There's really no
>>
>>>>> benefit
>>
>>>>>> unless you have room in your house to make a real server room
>>
>>>>> with
>>
>>>>>> racks and the electrical capacity to go along with it.
>>
>>>>>>
>>
>>>>>> On Thu, Jul 20, 2023, at 10:59 AM, Stephen Partington wrote:
>>
>>>>>>
>>
>>>>>>> the downside for these processors is their mainboards are
>> still
>>
>>>>> very
>>
>>>>>>> pricy to buy. much more than the CPU itself. you are almost
>>
>>>>> better
>>
>>>>>>> off looking for and buying a refurbished server which you can
>>
>>>>> get
>>
>>>>>>> for almost ludicrously inexpensive prices.
>>
>>>>>>>
>>
>>>>>>> On Thu, Jul 20, 2023 at 1:56 PM Ryan Petris via PLUG-discuss
>>
>>>>>>> <plug-discuss@lists.phxlinux.org> wrote:
>>
>>>>>>>
>>
>>>>>>> The CPU's cheap because it's old and no one wants them anymore
>>
>>>>> --
>>
>>>>>>> it's of the same generation as 6000 series intel processors
>>
>>>>> (i.e.
>>
>>>>>>> skylake). It also uses a server socket, so the only
>>
>>>>> motherboards
>>
>>>>>>> you're going to be able to find are server motherboards. Those
>>
>>>>> are
>>
>>>>>>> going to be expensive and/or have other quirks, such as
>>
>>>>> requiring a
>>
>>>>>>> vendor specific heatsink, or a vendor-specific power supply,
>> or
>>
>>>>> take
>>
>>>>>>> 5 minutes to start up, etc.
>>
>>>>>>>
>>
>>>>>>> You'd be better off spending money on a last-gen cpu and
>>
>>>>>>> motherboard, for instance here's a combination that is
>>
>>>>> relatively
>>
>>>>>>> cheap:
>>
>>>>>>>
>>
>>>>>>> $174 for an i5-12400, which according to cpubenchmark.net [1]
>>
>>>>> [1] is
>>
>>>>>>> nearly 30% faster than the Xeon you linked (score of 19501 vs
>>
>>>>> 15146,
>>
>>>>>>> much faster single-core score as well):
>>
>>>>>>>
>>
>>>>>>>
>>
>>>>>>
>>
>>>>>
>>
>>>>
>>
>>>
>>
> https://www.amazon.com/Intel-i5-12400-Desktop-Processor-Cache/dp/B09NMPD8V2/
>>
>>>>>>>
>>
>>>>>>> $139 for a compatible motherboard:
>>
>>>>>>>
>>
>>>>>>>
>>
>>>>>>
>>
>>>>>
>>
>>>>
>>
>>>
>>
> https://www.amazon.com/GIGABYTE-B760M-DS3H-AX-Motherboard/dp/B0BSP61QZC/
>>
>>>>>>>
>>
>>>>>>> I also wouldn't pay so much attention to the number of
>>
>>>>> "threads" you
>>
>>>>>>> think you'll need; you can run many VMs with a total number of
>>
>>>>>>> virtual processors that is much more than what you actually
>>
>>>>> have,
>>
>>>>>>> and as long as you're not trying to go whole hog on every
>>
>>>>> machine at
>>
>>>>>>> the same time you'll be fine, and even if you do, you'll still
>>
>>>>> be
>>
>>>>>>> better off with a faster processor with a few fewer threads
>>
>>>>> than an
>>
>>>>>>> older slower cpu with more.
>>
>>>>>>>
>>
>>>>>>> On Thu, Jul 20, 2023, at 10:26 AM, Keith Smith via
>> PLUG-discuss
>>
>>>>>>> wrote:
>>
>>>>>>>
>>
>>>>>>> Hi,
>>
>>>>>>>
>>
>>>>>>> I was surfing the Inter Web when I happened upon a Xeon server
>>
>>>>> CPU.
>>
>>>>>>> It
>>
>>>>>>>
>>
>>>>>>> is marked at $32.49 at Newegg. It has 12 cores and 24 threads
>>
>>>>> and
>>
>>>>>>> has a
>>
>>>>>>>
>>
>>>>>>> good benchmark score.
>>
>>>>>>>
>>
>>>>>>>
>>
>>>>>>
>>
>>>>>
>>
>>>>
>>
>>>
>>
> https://www.cpubenchmark.net/cpu.php?cpu=Intel+Xeon+Silver+4116+%40+2.10GHz&id=3179
>>
>>>>>>>
>>
>>>>>>> https://www.newegg.com/p/274-000A-007K2?Description=Xeon
>>
>>>>>>>
>>
>>>>>>> In the future at some point I would like to build something
>>
>>>>> with 20
>>
>>>>>>> plus
>>
>>>>>>>
>>
>>>>>>> or minus cores and 40 threads more or less for Proxmox. This
>>
>>>>> would
>>
>>>>>>> be
>>
>>>>>>>
>>
>>>>>>> over kills because I only need 1 or 2 VMs active at one
>> time...
>>
>>>>>>> maybe 3
>>
>>>>>>>
>>
>>>>>>> in an extreme situation.
>>
>>>>>>>
>>
>>>>>>> This 12 core/24 thread CPU with 64Gb of Ram and a 1Tb SSD
>> would
>>
>>>>>>> really
>>
>>>>>>>
>>
>>>>>>> be more resources than I would ever need. Off the top of my
>>
>>>>> head
>>
>>>>>>> this
>>
>>>>>>>
>>
>>>>>>> means I might be able to build a decent Proxmox server for
>> $500
>>
>>>>> -
>>
>>>>>>> $600.
>>
>>>>>>>
>>
>>>>>>> I do not need fancy video except for one VM that might be
>>
>>>>> running
>>
>>>>>>> Win 10
>>
>>>>>>>
>>
>>>>>>> or 11... I assume a server grade CPU would handle Win 10 and
>>
>>>>> 11?
>>
>>>>>>>
>>
>>>>>>> Am I on the right track?
>>
>>>>>>>
>>
>>>>>>> Thank You For Your Feedback!!
>>
>>>>>>>
>>
>>>>>>> Keith
>>
>>>>>>>
>>
>>>>>>> ---------------------------------------------------
>>
>>>>>>>
>>
>>>>>>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>>>>>>>
>>
>>>>>>> To subscribe, unsubscribe, or to change your mail settings:
>>
>>>>>>>
>>
>>>>>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>>>>>>>
>>
>>>>>>> ---------------------------------------------------
>>
>>>>>>>
>>
>>>>>>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>>>>>>>
>>
>>>>>>> To subscribe, unsubscribe, or to change your mail settings:
>>
>>>>>>>
>>
>>>>>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>>>>>>
>>
>>>>>> --
>>
>>>>>>
>>
>>>>>> A mouse trap, placed on top of your alarm clock, will prevent
>>
>>>>> you from
>>
>>>>>> rolling over and going back to sleep after you hit the snooze
>>
>>>>> button.
>>
>>>>>>
>>
>>>>>> Stephen
>>
>>>>>>
>>
>>>>>>
>>
>>>>>>
>>
>>>>>> Links:
>>
>>>>>> ------
>>
>>>>>> [1] http://cpubenchmark.net
>>
>>>>>
>>
>>>>>> ---------------------------------------------------
>>
>>>>>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>>>>>> To subscribe, unsubscribe, or to change your mail settings:
>>
>>>>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>>>>> ---------------------------------------------------
>>
>>>>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>>>>> To subscribe, unsubscribe, or to change your mail settings:
>>
>>>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>>>>>
>>
>>>>> ---------------------------------------------------
>>
>>>>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>>>>> To subscribe, unsubscribe, or to change your mail settings:
>>
>>>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>>>> ---------------------------------------------------
>>
>>>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>>>> To subscribe, unsubscribe, or to change your mail settings:
>>
>>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>>>
>>
>>> --
>>
>>>
>>
>>> Todd Cole
>>
>>> Ubuntu Arizona Team
>>
>>> 2928 W El Caminito
>>
>>> Phoenix AZ 85051-3957
>>
>>> toddc@azloco.com
>>
>>> 602-677-9402
>>
>>>
>>
>>>
>>
>>> Links:
>>
>>> ------
>>
>>> [1] http://cpubenchmark.net
>>
>>> ---------------------------------------------------
>>
>>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>>> To subscribe, unsubscribe, or to change your mail settings:
>>
>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>> ---------------------------------------------------
>>
>> PLUG-discuss mailing list: PLUG-discuss@lists.phxlinux.org
>>
>> To subscribe, unsubscribe, or to change your mail settings:
>>
>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
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