problem on 1TB filesystem RAID 5 3ware

[Mike Tancsa]

On Sat, 29 Mar 2003 13:48:15 -0600, in sentex.lists.freebsd.hardware you
wrote:

>
>>There have been broken 3ware firmwares in the past that specifically
>>effected RAID5. A quick test of the same hardware under LINUX or win2k
>>would confirm if this is another firmware issue or driver specific. Another
>>common issue across all platforms (i.e. firmware issue) was changing the
>>disk stripe to anything other than the default 64k on RAID0 or 10.  This
>>too would break things on all operating systems.
>
>We'd like to use the 3ware 7000-2 in non-RAID JBOD, to get the supposed 
>speed benefit of the 3ware "switch fabric", lower CPU overhead, etc. in 
>high-volume SMTP relays.
>
>Will whatever 3ware+FreeBSD somewhat "discutable" 3ware problems show up in 
>JBOD mode or are the problems limited to RAID?


I have *many* 3ware cards deployed in FreeBSD in RAID1, one very large news
server with several RAID0 stripes (it blasts 25Mb/s onto the drives 24hrs a
day) running dnews with about 55 concurrent clients reading at peak times)
and a busy sql server in RAID10 with excellent results.  I cant speak to
RAID5 as I dont have any application for that configuration, nor JBOD.
However, I have tested a pair of drives in RAID 1 vs the same drive on a
regular ATA controller. Even in RAID1, the reads are faster as both
spindles seem to be used in an intelligent way and we had no difference in
write speed

with respect for the RAID5 issues, try "raid5, 3ware, corruption, linux" on
google...

http://www.google.ca/search?q=cache:DXp1yfuL5RwC:computing.fnal.gov/cms/disk/performance/3ware/3Ware_CMS_Story.html+3ware+corruption+raid5&hl=en&ie=UTF-8



>Does anybody have experience or URL that says the 3ware 7000-2 @ $100 is 
>sufficiently "better" to justify it over an Promise "Ultra133 TX2" @ $40?

as JBOD, I doubt you would see any significant difference.  If you want
RAID0,1 or 10, I highly recommend the 3ware.


	---Mike
Mike Tancsa  (mike at sentex.net)	
http://www.sentex.net/mike