Re: [gentoo-user] hp H222 SAS controller

[Stefan G. Weichinger]

Am 03.07.2013 21:34, schrieb Paul Hartman:
> On Wed, Jul 3, 2013 at 2:29 AM, Stefan G. Weichinger <lists@×××××.at> wrote:
>> Am 03.07.2013 00:42, schrieb Paul Hartman:
>>> On Tue, Jul 2, 2013 at 2:56 PM, Stefan G. Weichinger <lists@×××××.at> wrote:
>>>>
>>>> Does anyone use that controller with gentoo?
>>>>
>>>> If yes, which driver/module does support it?
>>>>
>>>> I ordered one for a server and did not really check the facts ;-)
>>>
>>> Looks like it uses the LSI SAS2008 chipset (basically LSI controller
>>> with HP branding), so you should enable kernel module mpt2sas
>>> (CONFIG_SCSI_MPT2SAS) and probably some other SAS-related options will
>>> be required as well if you don't already use them.
>>>
>>> I actually just installed a card with this same chipset in my Gentoo
>>> machine yesterday! I have not attached disks to it yet, as I am
>>> waiting for the enclosure to be delivered, but so far nothing froze or
>>> burst into flames when the module loaded. :)  I even upgraded the BIOS
>>> and firmware on the card from within linux and everything seems okay,
>>> so far.
>>
>> Thanks a lot, Paul, for that feedback. Seems that you will be the first
>> to really test it, my box will arrive next week, I assume. This will be
>> an installation from scratch so no SAS-related stuff there already.
>>
>> I wonder if it makes sense to attach the disks to that adapter as well?
>> This box will do amanda backups ... so there will be the amanda holding
>> disk and it is important to have maximum speed between that holding area
>> and the tape drive. I plan RAID1 on 2x2TB disks at least or maybe even
>> RAID0 (it's a rather temporary storage area so the redundancy isn't that
>> important). Testing will show!
>
> Mine will be attached to an external 8-disk storage array with 2
> external SAS cables (4 disks per cable). I had a 5-disk 8TB software
> RAID5 in my computer that I had to remove due to an unplanned
> motherboard upgrade. Right now the disks are in a cheap external
> 5-disk eSATA/USB JBOD enclosure plugged into the eSATA port on my
> motherboard, but it's not able to access all disks at the same time,
> so the RAID5 performance is awful. Around 10-20 MB/sec on writes and
> max 50MB/sec on reads. (It was previously 100MB+/sec for both
> operations.)
>
> In the eSATA enclosure, a single scrub (check) of my array takes FOUR
> DAYS to complete! I worry about what will happen if I have to replace
> a disk, the rebuild would take forever... what if there is a power
> outage and my UPS battery only lasts around 30 minutes?
>
> I bought two of the lowest-quality 4tb Seagate drives for US$140 each
> on sale and plan to use them to make a backup copy of my files from
> the RAID onto those drives. So far I have never made a backup of my
> RAID because I never had enough storage space to duplicate it all.
> "RAID is not a backup" has been repeating in my head for all these
> years. Horror stories about a corrupt filesystem, or 1 bad sector
> causing the whole RAID5 rebuild to fail. Now that I will have extra
> drive bays, maybe I can add a second parity drive and try to do an
> online upgrade from RAID5 to RAID6. I definitely want to make a good
> backup before I try that...
>
> I am hopeful that the SAS controller and enclosure should give me high
> performance again! I will let you know how it goes.
>
> BTW, I am using the latest 3.9 series linux kernel.

My planned box will be a stable gentoo installation so that will mean
3.8.13 for now. No problem, I assume.

Thanks for your description ... good luck with that!
I will maybe pre-install that system in a VM until the hardware gets
here ;-)

Stefan