Re: [gentoo-user] VMWare Hypervisor - SD vs CF card?

[Matthew Marlowe]

On Tue, Jun 19, 2012 at 4:47 AM, Tanstaafl <tanstaafl@×××××××××××.org> wrote:
> I could get 2 of these for each server, each with a mirrored pair of CF (or
> SD) cards (mirror mode is defined by a jumper or switch on the adapter),
> then mirror those (in the BIOS), which would result in a total of FOUR CF
> (or SD) redundant cards (a mirror of 2 mirrored pairs) for the hypervisor...
> and I can do this for quite a bit less than even a SINGLE 146GB SAS drive...
>
> Is there any reason NOT to do this?
>

If you have a small ESX cluster, there are numerous advantages to
having some local storage on each your ESX hosts in addition to your
primary SAN storage:
- Testing major ESX version upgrades prior to rolling out to cluster
(converting VM's to new hardware format, while leaving old VM's on
SAN)
- If your setup is too small to have high performance spare SAN
devices + storage, what do you do when you have to do a major upgrade
of the SAN and/or possibly perform data destructive RAID format
changes? iSCSI storage vmotion would allow you to migrate VM's to
local storage on ESX servers while SAN is upgraded...several extra
hard drives + raid controllers are cheaper than buying another
equalogic/emc device.
- Some cluster backup software like to replicate backup data outside
of the SAN and backup server.....I felt much better when I was
performing nightly backups from the SAN to local storage on the ESX
boxes and then exporting the dedup'd backup data to backup server for
writing to tape.  But, there are many ways to resolve this.
- Local ESX storage is much cheaper than SAN...there were several
cases where I used to run production VM's via SAN, and temporary
dev/test VM's on ESX server local storage
- Lastly, I never really have been a fan of ESXi as an upgrade from
ESX.....seems that it was more driven by vmware making windows admins
feel more confident since they didn't have to learn linux for ESX
console.

But, there is nothing keeping you from getting mirrored CF/SD cards
for the hypervisor boot and also keeping a few mirrored 2TB SATA
drives on each host for local datastores (7200rpm SATA is much cheaper
than 15K rpm SAS).

Of course, for large ESX clusters, you can probably afford numerous
SAN devices which would negate most of the above.

Matt