To RAID or not to RAID

Undoubtably this had been thrashed around, but I missed it.

RAID 5 looks very nice for striping disks together, but I'd like to know the
benefits/downfalls of doing this.

What is the benefit of having one large partition with many subdirectories
(using no_atime on Linux etc) over having multiple directories on many disks
(the default that happens)? Does having two large RAID 5 partitions (say on
twin SCSI controllers) reduce or enhance performance rather than one striped
set?

Do more (or less) sub-directories impact performance?

If you RAID, can you add another disk without losing your cache contents,
ie, just make it bigger? Last I checked if you added more cache_dir
sections, it wiped your stored files and started clean.

Given that RAM isn't a problem, is there any performance issues with using
NOVM or the normal (VM?) code?

Thanks,
Antony.

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Received on Tue Nov 25 1997 - 21:53:02 MST