ProLiant DL380 G6 RAID 5 rebuild time

[chris_stiv]

Hi,

I see some other posts about this topic so sorry for duplicating those, but id like an answer myself.

I have a 550GB RAID 5 array on a Smart Array P410i controller. A drive had failed and the active spare appears to be rebuilding. The little animated "plus" icon is all that tell me this.

Am i right with the 15min per GB estimate? That means 137 hours! I notice the rebuild priority is at medium, is there any speed gained from setting this to high? Or turning on the Pysical Write Cache? This server is on a UPS.

The strange thing is that the drive was reported as failed last Thursday, but im not convinced the array started rebuilding right away, is that possible? For one it should be completed by now right? I have phoned support and they say it all checks out OK however.

Thanks,

Chris

[SMR]

Hi,

The rebuild time on new gen controllers like the P410i is slightly faster, those 15 min per gig have been around for years... these chips are faster as are the drives that they control. The rebuild speed will increase when set to High only if the server is currently under heavy production disk I/O thus taking a hit on production I/O to gain better rebuild speed, otherwise Medium is fine for most disk workloads. If by write cache you mean the array accelerator then yes, it will dramatically increase performace, you should enable it, if there is no battery installed you assume the risk of possible data loss on power failure but as you mentioned, the box is running on a UPS.