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Useful RAID Tools?
msaes asks: "I've got 4 machines now that I'm running RAID5 on. 3 are Dell's with the PERC (Adaptec) SCSI RAID controller, and one is a software (Win2k Pro) RAID. In all 4 cases, the MS defrag program, and the Norton Speedisk program said that the logical drives are horribly fragged. And from disk I/O performance, I'd tend to agree. Running the MS defrag on any of them is futile. It just cranks away for a while and then cheerfully says that it's done, with little or no improvement. I've run Speedisk on the software RAID machine and it's run for about 3 days solid now and performance on the drive is only getting worse. My question is: Does de-fragmentation software get confused by RAID volumes and actually fragment the drive worse?" Which brings yet another question. What tools are out there for the effective management of RAID volumes? Other partition types have a wide variety of maintenance tools, aside from the defrag utility, like a partition editor, an undelete tool, analyzers, and so on. What about RAID? What tools do you use to make sure your RAID volumes are happy and healthy?
We have several(5??) Dell 540 Precision Workstations that are Win2K with a level 1 RAID setup for GIS. We run Disk Keeper on them and it seems to keep it up. For the most part they seem to be ok w/o trouble.
We have another one we use for a server with level 1 RAID and we have never ran any type of disk tool on it and it seems to work just fine but it is mostly used for uploading images.
In short. Alot of use Buy Disk Keeper if not dont worry about it or reformat and reinstall.
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Like 2 previous posters, get and use Diskeeper. I've used it going back to the 1.x releases and its done nothing but improve. MS Defrag is based on a old version of Diskeeper that is can't be scheduled. It's junk. Further, Executive Software, the publisher of Diskeeper, wrote the API for defragmentation. And it's what Norton uses for SpeedDisk in NT flavored OSes. But Diskeeper is much faster. Besides, it will defragment your directories, MFT and paging files as well.
On the Dell PERC(2) Adaptec, not the PERC(II) AMI, turn off read and write caching (can be performed through the software tool) befor defragging. The read and write cache will confuse degrag software. Not a problem with the AMI PERC (aka MegaRaid). Once done, turn back on. This cannot be scheduled, so you have to be there.
These Perc controllers are integrated on the hardware it seems and need special drivers that may interact in some weird way with some parts of the operating system. That is why i stay way of internal raid cards. I always try to go for external storage with its own embedded intelligence, and these plug to the servers using standard scsi or fibre adapters. This brings some added advantages to us. In low end servers i can use external scsi raid boxes with ide disks, with a very low cost per MB, and very good reliability. I can make the servers boot easily from the raid boxes with no dependency on special storage drivers. I can exchange servers in a snap if they break or if i want to upgrade, the new server just needs to have the same scsi card, and with Linux the rest is piece of cake. And with the cost for storage with more than one host channel going down, i can plug more than one server to the same storage, both sharing filesystems (Gfs) or raid logical disks.
/Pedro