freebsd-performance Digest, Vol 4, Issue 7
Eric Anderson
anderson at centtech.com
Wed Jun 18 13:44:28 PDT 2003
Jin Guojun [DSD] wrote:
> Eric Anderson wrote:
>
>
>>>Very minimum.
>>>It was slow on SCSI bus , but I do not have time to diagnose,
>>>which can be very time consuming.
>>
>>My tests have shown that a GOOD hardware RAID5 controller can really
>>help you out when it's being slammed (specially over NFS) - I use Dell
>>PERC/2 and PERC/3 controllers (rebranded AMI RAID boards). They run
>>like champs, and I get 40MB/s sustained xfers..
>
>
> What did you mean sustained xfers ? -- in and out, or just read out.
sustained writes (not burst transfers) and sustained reads.. With
hardware RAID's that have cache memory on them (as the PERC's do - mine
has 128mb), you can get huge burst speeds (all in memory, so it makes
sense). If you have a machine that is writing small files constantly,
the cache can significantly help. However, putting a lot of extra
memory in the server running a software RAID can do this with similar
results. I always suggest piling on the RAM for servers..
Eric
--
------------------------------------------------------------------
Eric Anderson Systems Administrator Centaur Technology
Attitudes are contagious, is yours worth catching?
------------------------------------------------------------------
More information about the freebsd-performance
mailing list