Raid 5 and 10.000 rpm & 15.000 rpm

[Norman Tan]

Hello.
I have a raid 5 with three 18.2 GB Hot-Swap SCSI HD´s with 15.000rpm. I also have 2 HD´s with 18.2 GB and 10.000rpm.
When one of my Raid-5 Disks fail, can i replace it with one the 10er?
What does happen with the performance?
Can I extend the Raid 5 with the 10ers?
Thank you very much!
Norman

[Andrew Young_2]

Hi Norman.

The effects on disk reading will be a slightly reduced seek/read time depending on which disk it tries to read from.

Write performance will effectively be reduced to 10K speeds since a write is only complete when both writes are complete. If you have write cache enabled on the controller this can be mitigated to a greater or lesser extent.

I am not sure if the controllers have logic to favour disks with faster read/seek times.

Regards

Andrew Y

[e4services]

When one of my Raid-5 Disks fail, can i replace it with one the 10er? Yes

What does happen with the performance? degrades when the 10k is accessed

Can I extend the Raid 5 with the 10ers? Yes

[Blazhev_1]

Hi,

I fully agree to both replies above.
The difference is that the 10k drive will need more time to give the data to the controller. Since the 10k's are in the same RAID 5 every time you access the array it will need little more time, but like Andrew explained, the disk will cache data on the BBWC and think you will not feel a big difference in performance.

Regards,
Pac