[TriLUG] TriLUG Server Refresh

Thu Apr 30 15:20:35 EDT 2015

Depends on the requirements.  If speed is favored over space, RAID 10 is
better.  If stability is favored over speed, I would suggest RAID-6
(dual-parity).  These questions depend on performance requirements, number
of VMs to be hosted, the time it takes to get to the server and replace the
drive, etc.

For what its worth, I normally do RAID-6 setups where performance is not
critical simply because it gives me more time to replace a bad drive.
Using RAID-5, you only have so much time available before the next drive
goes bad.  I have not had bad luck with RAID-5 or RAID-6.  But, I tend to
pick only enterprise-rated drives with high-quality RAID cards (LSI).

Finally, SSDs are great *if* you need the performance and are willing to
spend the money.  Right now, you can get the Samsung 850-EVO 1TB SSD drives
for about $400/ea.  If 1TB is enough space, get two and put them in a
RAID-1 configuration.

On Thu, Apr 30, 2015 at 2:13 PM, Stephen P. Schaefer via TriLUG <
trilug at trilug.org> wrote:

> Perhaps you folks are smarter or luckier than I am, but I've had grief
> with RAID5.  Perhaps RAID 10 would be easier?
> http://www.cyberciti.biz/tips/raid5-vs-raid-10-safety-performance.html
>
> Independently, due to Linux's aggressive memory caching (presuming the
> hypervisor keeps its guest images on a file system rather than raw
> devices), you won't get as much bang from SSD as you would in Windows or
> MAC.  If you're going to spend money on SSD, I'd suggest using it for
> swap or /var on the hypervisor.
>
> (For workstation Linux, SSD can reduce boot times by a lot, but I
> presume the hypervisor won't be running an end-user graphics stack.)
>
> On Thu, Apr 30, 2015, at 01:30 PM, Jonathan Mainguy via TriLUG wrote:
> > OS for the Host - Centos or Debian
> > Drives - atleast 2, raid + lvm (Software raid is pretty good these days
> > with mdstat)
> > IPv4 - Haproxy for all web traffic, will divert to the appropriate vm. 22
> > goes direct to vm, some other port for ssh to the host. iptables /
> > haproxy
> > for the other stuff like mail.
> >
> > On Thu, Apr 30, 2015 at 1:22 PM, Mauricio Tavares via TriLUG <
> > trilug at trilug.org> wrote:
> >
> > > On Thu, Apr 30, 2015 at 1:00 PM, Bill Farrow via TriLUG
> > > <trilug at trilug.org> wrote:
> > > > TriLUG has acquired a new rackmount server from ncsu-lug. The
> Steering
> > > > Committee (SC) intends to replace our existing server, Pilot, by
> > > > moving it into a VM running on this new hardware. The plan is to
> > > > purchase new hard drives, install a small host OS, and bring up a kvm
> > > > guest of "pilot". We could use some help and advice:
> > > >
> > > > * How many disks should we buy ?
> > >
> > >       Correct me if I am wrong but it is a 2U with 6 drive bays.
> > > Personally I would get at least 4 drives: 2 small ones (SSD?) for the
> > > OS and 2-4 large ones for the VMs (raid 1 or 5). For the large drives,
> > > how much are 2TB nowadays?
> > >
> > > > * How should the disks be managed (lvm, raid, etc) ?
> > >
> > >       Since lvm now can do raid, I would suggest that.
> > >
> > > > * What host OS ? (Pilot is Ubuntu 12.04 LTS)
> > >
> > >       It depends on how you want to deploy. Personally I want to do as
> > > lightweight vm host os as possible, so something like alpine linux
> > > would be a starting point. That said, it would make sense it to be
> > > Ubuntu 12.04 LTS because of what people are comfortable with.
> > >
> > > For which vm thingie to run, I personally have run esxi, kvm/qemu,
> > > vbox, and xen. I can help with any of those but I only have packer
> > > scripts (to spool up vms) for esxi and kvm. I would also later suggest
> > > to run docker/juju but having that server to be a vm.
> > >
> > > > * How do we manage the host and VMs if we only have 1 public ipv4
> > > address ?
> > > >
> > >       That is a router issue: ports (PAT?). But you will need to do
> > > that anyway depending on which other services you will provide. But,
> > > we can have some weird port to ssh into the host... using of course
> > > "password" as the password.
> > > >
> > > > Current Server:
> > > >   Supermicro X6DH8-XB, 2x Intel Xeon Dual-Core 3.2GHz, 2GB RAM
> > > >   3ware 9000 Storage Controller
> > > >   8x WDC WD2500SD-01KCC0 Hard Drives
> > > >   1x FUJITSU MHT2040BH
> > > >
> > > > New Server:
> > > >   Dell PowerEdge 2950, 2x Intel Xeon X5450 3.0GHz, 32GB RAM
> > > >   8x empty drive slots for 2.5" SATA HDD
> > > >   http://trilug.org/~bgerard/moya.specs.tgz
> > > > --
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> > > --
> > > This message was sent to: Jon Mainguy <jon at jmainguy.com>
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> > --
> > This message was sent to: sschaefer at acm.org <sschaefer at acm.org>
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> that
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> > Welcome to TriLUG: http://trilug.org/welcome
> --
> This message was sent to: Ron Kelley <rkelleyrtp at gmail.com>
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>