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Rebuild Rates on SATA II 1 TB Drives
I currently have 3 RAID 5 Groups 5 disks each of the 1 TB SATA II Drives...has anyone had any rebuild experience on these or something close? I have a CX3-40c.
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AranH1
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July 13th, 2009 15:00
Second, I think your fear that a SATAII hot spare will replace a failed FC drive is unfounded. Yes, technically a SATA hot spare can replace a failed FC drive, but as long as you have sufficient FC hot spares in the array of the appropriate size then a SATAII hot spare will not be invoked for a FC drive. In the past four years I have been managing multiple CLARiiONs with FC and SATAII drives and have never had this happen. Plan your hot spare assignment according to EMC best practices, which translates to one hot spare for every 30 drives.
Regarding your RG layout a third option would be two RAID5(6+1) and one hot spare. That would spread your LUNs over more spindles and reduce the amount of overhead lost to RAID parity for that enclosure.
dynamox
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July 9th, 2009 17:00
RyanP2
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July 10th, 2009 07:00
Not taking credit for the answer but if your having problems locating the doc here is the link:
http://powerlink.emc.com/km/live1/en_US/Offering_Technical/White_Paper/H4153-the-influence-of-priorities-on-lun-mgmt-optns-wp.pdf
-Ryan
ZaphodB
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July 10th, 2009 10:00
Here are a few things that come to mind:
AranH1
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July 13th, 2009 12:00
JaniceHetrick
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July 13th, 2009 12:00
I understand there are many factors to rebuilds
JaniceHetrick
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July 13th, 2009 14:00
Scenario 1:
One shelf of 15 1TB SATA II drives that I plan on setting up as such:
Disks 0-4 RAID 5 (4+1)
Disks 5-9 RAID 5 (4+1)
Disks 10-13 RAID 5 (3+1)
Disk 14 Hot Spare
OR
Scenario 2:
One shelf of 15 1TB SATA II drives that I plan on setting up as such:
Disks 0-4 RAID 5 (4+1)
Disks 5-9 RAID 5 (4+1)
Disks 10-14 RAID 5 (4+1)
Issue...Scenario 1 with the hot spare I have found maybe an issue since a SATA II drive could be used for one of my FC drives (for which I have 2 hot spares already)
Issue...Scenario 2 without a hot spare I need to know how long the rebuild rate will be on a 4+1 RAID 5 (thanks to a previous post I have that calculation)
Main concern is do I spread the RAID groups throughout the shelf or keep them as I listed above (0-4, 5-9, 10-14) or from reading through best practices it seems that the RAID groups are spread out within the shelf.
Really what I am trying to do is get the best bang for my buck and keep the rebuild within reason. RAID 6 is out for now due to I have FLARE 24 not 26 on my CX3-40c.
Any input is appreciated!
kelleg
4.5K Posts
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July 15th, 2009 07:00
EMC CLARiiON Storage System Fundamentals for Performance and Availability
http://powerlink.emc.com/km/live1/en_US/Offering_Technical/White_Paper/H1049_emc_clariion_fibre_channel_storage_fundamentals_ldv.pdf
EMC CLARiiON Best Practices for Fibre Channel Storage: FLARE Release 26 Firmware Update - Best Practices Planning
http://powerlink.emc.com/km/live1/en_US/Offering_Technical/White_Paper/H2358_clariion_best_prac_fibre_chnl_wp_ldv.pdf
Also, if you feel that your questions have been answered could you please mark the question as answered, awarding points to the replies that best answered your question.
glen