From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On Behalf Of Feizhou > > > > About 10 seconds after I started this thread, I remembered > a long discussion about > > RAID, SATA, etc., 2 or 3 months ago. I think that Feizhou > (?) strongly recommended > > going with Software RAID in CentOS. I will search for that > and do a lot of > > reading. RAID 1 for mirroring is what I want. Lanny > > Whoa there! > > Hardware raid + battery backed up memory cache in raid 1,10 > mode is hard > to beat with software raid and hardware raid offers data integrity > guarantee beyond software raid. > > If you were planning a huge array especially a raid5 array, then > software raid may be better. Hardware RAID cards all come with memory > caches now so their throughput is no longer limited. > > Another route you can go is getting a PCI/PCIe/PCI-X BBU > RAM/NVRAM card > to put an external journal on to speed up fsync performance for > filesystems like ext3 over software raid since these cards > can go beyond > 1GB of memory unlike hardware raid cards that usually max out > at 256MB. What are some of these BBU NVRAM cards that I keep hearing people talk about? I would love to check them out. > Software RAID is also good if you need to be able to transfer > the disks > to another box that does not have a hardware raid controller > or the same > controller. > > Weigh these in your decision. :-) For 2 SATA hard disks used for the OS I think HW RAID is overkill. Besides I do not believe the PERC 5IR has BBU cache, that controller is really only meant as a simple RAID1 controller for the OS. If you use HW RAID you will need to install the manufacturer's software for monitoring it for a hard disk failure. If you wanted to add additional storage, say a SAS/SATA enclosure of 15 disks, then I would definitely invest in a HW RAID card for that! -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.