FC and SATA II Global Hot Spares

Question

I recently added a shelf of 1 TB SATA II drives and I am creating 3 RAID 5 Groups with 5/5/4 disks. I wish to use the last disk as a global hot spare, but I read through the Global Hot Spares best practices and found that there is a possibility that a SATA II drive could be used as a FC hot spare! Can anyone confirm this? The best practices state that a hot spare disk drive is selected by type (ATA or SATA II/FC), size and bus number. I really do not want a SATA II drive being used as a FC hot spare so any help or feedback is appreciated!!

dynamox · Answer

take a look at this discussionhttps://forums.emc.com/forums/thread.jspa?messageID=656817򠖱

JaniceHetrick · Answer

Thank you for the reference to that thread. It is exactly as I feared...a SATA II drive can hot spare for a FC drive which is really just crazy!! I wish they considered that at the controller level when they decided to allow SATA II shelves to be added to the CX3 series.

ZaphodB · Answer

But a SATA drive would only be invoked to spare a FC drive if there was no available FC hot spare of sufficient size. It won't happen 'randomly'.

RRR · Answer

It's a last resort ! So IMHO you're better of with a SATA HS invoked than running in degraded mode if you love your data !

What would perform better ?
- degraded Raid5 Raid Group (for example 4 x FC + 1 x SATA HS invoked)
- degraded Raid5 Raid Group without any HS invoked

The first option certainly is safer !

CLARiiON

FC and SATA II Global Hot Spares