Quoting <15AD5D7936F8D21198240000F831776E3E81AB at dboexc1.dbo.cpqcorp.net>
by "Jakma, Paul" <Paul.Jakma at compaq.com>:
> > Even with writeback, any raid5 implementation I've used (*) has
> > sucked. You
> then the controller is parity-bound. RAID5 should be faster at
> writing than RAID1 if the controller can do the parity calculations
> fast enough.
How's that, then? The minimum sensible RAID5 is three disks, so every
write involves writing to at least three disks, plus the parity
calculation time. By contrast, a mirror requires 2 disks and two
writes. If the mirrors are located on seperate controllers for
controller redundancy, the SCSI layer can even dispatch the writes
concurrently to the two controllers.
When asked if it is true that he uses his wheelchair as a weapon he will reply:
"That's a malicious rumour. I'll run over anyone who repeats it."
Stephen Hawking - [http://www.smh.com.au/news/0001/07/features/features1.html]
David Murphy - For PGP public key, send mail with Subject: send-pgp-key
Maintained by the ILUG website team. The aim of Linux.ie is to
support and help commercial and private users of Linux in Ireland. You can
display ILUG news in your own webpages, read backend
information to find out how. Networking services kindly provided by HEAnet, server kindly donated by
Dell. Linux is a trademark of Linus Torvalds,
used with permission. No penguins were harmed in the production or maintenance
of this highly praised website. Looking for the
Indian Linux Users' Group? Try here. If you've read all this and aren't a lawyer: you should be!