[ale] Getting rid of VMware

Fri Mar 12 08:58:56 EST 2021

HI,

iSCSI is supposed to work just like a regular SCSI disk; your computer
"mounts" the disk just like it would a locally-connected disk.  The main
difference is that instead of the LUN being on a physical wire, the LUN is
semi-virtual.

As for your VM issues...  If you have 4 24-core machines, you might want
to consider using something like oVirt to manage it.  It would allow you
to turn those machines into a single cluster of cores, so each VM could,
theoretically, run up to 24 vCores (although I think you'd be better off
with smaller VMs).  However, you will not be able to build a single,
96-core VM out of the 4 boxes.  Sorry.

You could also set up oVirt to use iSCSI directly, so no need to "go
through a fileserver".

-derek

On Fri, March 12, 2021 8:47 am, Tod Fassl via Ale wrote:
> Yes, I'm in academia. The ISCSI array has 8TB. It's got everybody's home
> directory on it. We did move a whole bunch of our stuff to the campus
> VMWare cluster. But we have to keep our own file server. And, after all,
> we already have the hardware, four 24-core machines, that used to be in
> our VMWare cluster.  There's no way we can fail to come out ahead here.
> I can easily repurpose those 4 machines to do everything the virtual
> machines were doing with plenty of hardware left to spare. And then we
> won't have to pay the VMWare licensing fee, upwards of $10K per year.
>
>
> For $10K a year, we can buy another big honkin' machine for the beowulf
> research cluster (maintenance of which is my real job).
>
>
> Anyway, the current problem is getting that ISCSI array attached
> directly to a Linux file server.
>
>
> On 3/11/21 7:30 PM, Jim Kinney via Ale wrote:
>>
>> On March 11, 2021 7:09:06 PM EST, DJ-Pfulio via Ale <ale at ale.org> wrote:
>>> How much storage is involved?  If it is less than 500G, replace it
>>> with an SSD. ;)  For small storage amounts, I wouldn't worry about
>>> moving hardware that will be retired shortly.
>>>
>>> I'd say that bare metal in 2021 is a mistake about 99.99% of the
>>> time.
>> That 0.01% is my happy spot :-) At some point is must be hardware. As I
>> recall, Tob is in academia. So hardware is used until it breaks beyond
>> repair.
>>
>> Why can't I pay for virtual hardware with virtual money? I have a new
>> currency called "sarcasm".
>>> On 3/11/21 5:37 PM, Tod Fassl via Ale wrote:
>>>> Soonish, I am going  to have to take an ISCSI array that is currently
>>>> talking to a VMWare virtual machine running Linux and connect it to a
>>>> real Linux machine. The problem is that I don't know how the Linux
>>>> virtual machine talks to the array. It appears as /dev/sdb on the
>>>> Linux virtual machine and is mounted via /etc/fstab like its just a
>>>> regular HD on the machine.
>>>>
>>>>
>>>> So I figure some explanation of how we got here is in order. My
>>>> previous boss bought VMWare thinking we could take 4 24-core machines
>>>> and make one big 96-core virtual machine out of them. He has since
>>>> retired. Since I was rather skeptical of VMWare from the start, the
>>>> job of dealing with the cluster was given to a co-worker. He has
>>>> since moved on. I know just enough about VMWare ESXI to keep the
>>>> thing working. My new boss wants to get rid of VMWare and re-install
>>>> everything on the bare metal machines.
>>>>
>>>>
>>>> The VMWare host has 4 ethernet cables running to the switch. But
>>>> there is only 1 virtual network port on the Linux virtual machine.
>>>> However, lspci shows 32 "lines with VMware PCI Express Root"
>>>> (whatever that is):
>>>>
>>>>
>>>> # lspci 00:07.7 System peripheral: VMware Virtual Machine
>>>> Communication Interface (rev 10) 00:10.0 SCSI storage controller: LSI
>>>> Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI
>>>> (rev 01) 00:11.0 PCI bridge: VMware PCI bridge (rev 02) 00:15.0 PCI
>>>> bridge: VMware PCI Express Root Port (rev 01) [...] 00:18.7 PCI
>>>> bridge: VMware PCI Express Root Port (rev 01) 02:00.0 Ethernet
>>>> controller: Intel Corporation 82545EM Gigabit Ethernet Controller
>>>> (Copper) (rev 01)
>>>>
>>>>
>>>> The open-iscsi package is not installed on the Linux virtual machine.
>>>> However, the ISCSI array shows up as /dev/sdb:
>>>>
>>>> # lsscsi [2:0:0:0]    disk    VMware   Virtual disk     1.0
>>>> /dev/sda [2:0:1:0]    disk    EQLOGIC  100E-00          8.1
>>>> /dev/sdb
>>>>
>>>>
>>>> I'd kinda like to get the ISCSI array connected to a new bare metal
>>>> Linux server w/o losing everybody's files. Do you think I can just
>>>> follow the various hotos out there on connecting an ISCSI array w/o
>>>> too much trouble?
>>>>
>>>>
>>>>
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-- 
       Derek Atkins                 617-623-3745
       derek at ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant