* Derek Simkowiak <[email protected]> wrote on [01-03-10y 15:35]:
> May I ask, why must it be hardware RAID? Linux's software RAID is
> usually as fast -- and sometimes faster -- than hardware RAID:
>
> http://www.linux.com/news/hardware/servers/8222-benchmarking-hardware-raid-vs-linux-kernel-software-raid
>
> I've built a handful of 4TB+ software RAID systems, and it works
> great. Red Hat and Ubuntu (9.10) both include a nice RAID management
> GUI called Palimpsest. Linux's software RAID also has a couple of
> advanced features that most hardware cards don't. The best feature: you
> can upgrade or migrate your hardware without any dependence on a
> particular hardware RAID card. All you need is SATA.
I like this idea, after looking through the management interface of
palimpset. My only experience with software RAID was with a Terastation
1TB a few years back. It was so horribly slow, I got rid of it after 10
days. I don't remember the numbers, but it was borderline worthless.
How does a modern linux kernel running software RAID do with CPU usage?
A good example would be for transcoding video. Its very CPU intensive,
and fairly IO heavy, but in mostly contiguous blocks. Will this bog
down the system to the point that other users won't be able to make
light web requests, or incoming (fairly light) e-mail, will start to
drop due to excessive latency?
Of course all systems are different, I'd just like to know your
experiences.
Thanks,
-- Ryan
>
> My advice would be to turn off the RAID function in your Dell card,
> so it treats all the disk as simple SATA drives (sda, sdb, sdc ... sdf),
> and then set up software RAID.
>
> --Derek
>
> P.S.> I recently lost data on a top-end hardware RAID system because a
> 3ware card had a compatibility issue with some hard drives. A few weeks
> later both 3ware and the drive Mfr. issued firmware updates to "fix" it.
>
> P.P.S.> I recently had a top-end LSI hardware RAID system fall over due
> to an un-acknowledged drive compatibility issue. I had no choice but to
> swap out the LSI card for a 3ware card. Did I mention that Linux
> software RAID is awesome?
>
>
> On 01/03/2010 03:11 PM, Ryan Allen wrote:
>> Hi SSL,
>>
>> I just purchased 4 new 1TB SATA drives, and attempted to upgrade my
>> RAID 5 system to 3 TB. however my Dell CERC 6 channel SATA RAID card
>> will only let me build a RAID volume up to 2 TB.
>>
>> I couldn't find any firmware upgrades on this horribly supported
>> el-cheepo raid card. At least its been a solid work horse, with
>> little problems aside from a horrible UI utility called afacli.
>>
>> I am looking for a hardware RAID card, PCI-X (100MHz), that has an
>> fairly easy to use UI that is well supported in Linux. It should
>> also take advantage of ALL my drive space for an expected volume of a
>> little under 3TB.
>>
>> Any suggestions? I would like to not spend $550 on an fancy 3ware
>> card either. Anything in the $100 range?
>>
>> Thanks,
>> Ryan
>>
>>
>>
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