SATA controllers

[Tom H]

>>> /me rotfl. I definitely do not remember ever reading about or discussing
>>> reviews of sata controllers on the Centos list.

>> I have; in interminable threads about RAID controllers and SASvSATAvSCSI.

> Reviews? Discussions/arguments about raid controllers and type of
> interconnects yes but reviews? Just nitpicking :-P

A review is just a one-way, totally biased discussion! :)


>>>> If you are looking for software (mdadm) RAID, make sure that you do
>>>> not buy a FakeRAID card.

>>> It would be a bit hard to find a 4 port non-raid sata controller. After
>>> all, they get to charge a premium for a slightly modified bios. At least
>>> here in Hong Kong anyway.

>> Probably true. I have never considered buying such a card.

> Not a software raid guy eh? Well, I'd rather do hardware raid + bbu
> cache for anything that is not raid1+0 or raid1 or raidz
> (OpenSolaris/Solaris) too. It would be nice to see a PCIe 8-port SATA
> controller that also support PMP. Might make for a nice cheap storage
> solution given the right motherboard and interface. Right now, I think I
> will have to settle for Supermicro's LSI based non-raid dual SGPIO port
> SAS controllers and its 6 SGPIO port backplane.

For anything not originating from a SAN, I prefer software RAID... But
the companies where I moonlight generally cannot afford SANs and since
their Windows admins only swear by hardware RAID, I end up having to
fight for a big enough budget to get a good RAID card - and hopefully
have them choose mdadm in order to cut the server cost. I will stop
here beofre this turns into one of the CentOS/Debian RAID fests


>> I made that point because Karmic will try quite aggressively dmraid,
>> as we have seen in a previous thread.

> Oh, missed that thread. Hmm,
> https://help.ubuntu.com/community/FakeRaidHowto has a rather specious
> reason for 'promoting' dmraid. Does dmraid support barriers? If not,
> Karmic is then doing an installation that is by nature not data safe.
> Nice, let's do an installation that will potentially cost a new user
> his/her data or might be rendered useless in the event of a crash/power
> failure instead of promoting other choices like WUBI, using a VM or
> *gasp* buying a hard disk.

The problem with dmraid is that manufacturers like it so they can
cheap(er) RAID especially to desktop users. Pre-9.10, getting dmraid
to work was painful (I even remember seeing a help.ubuntu.com or
wiki.ubuntu.com page saying that it was not really supported but then
more or less explaining how to use it) so the developers seem to have
tipped the balance the other way for Karmic.

AFAIK, LVM does not support barriers. This is not a topic that I know
much about though...