rebuild times for P2000 G3??

[Tom Lyczko]

I wonder if anyone has had any real-world or even *estimated* experience rebuilding a RAID6 MSA P2000 G3 array??

With 600 GB or 900 GB SAS drives?? -- the 12-disk array?? or even any of the larger arrays??
Approximately how long did it take??
Is there any way to even *estimate* rebuild times for a given array??
Thank you, Tom

[Dennis Handly]

Rebuild times depends on several factors:

1) Size of the disk being replaced

2) I/O transfer rate

3) For RAID 6, it must read N-1 disks to recompute the parity

4) How much other host I/O is going on

[Tom Lyczko]

I realize many factors are involved -- that's why I asked if anyone had experienced it in REAL LIFE..it's an unfortunate event that hopefully does not happen often, but any sort of information along these lines would be helpful.

Thank you, Tom

[Mike Texter]

Usually it pays to err on the side of assuming the rebuild will take longer than you think it will.  Unfortunately, during the rebuild, the disks are more stressed than normal and you're more likely to have another failure during that time.  For this reason I wouldn't recommend going much more than 6 large disks to an array, it minimizes your risk (and your rebuild time).  If you're looking for hard numbers, I apologize for not having any, but a rough guesstimate for 900GB 10k sas disks in a 12-disk array, in a RAID-5 set, you'd be looking at 1-3 days for a rebuild.  And of course depending on all of the factors that were mentioned above.

[Tom Lyczko]

Guess-timates and anyone's (unfortunate) real-world experiences are what I am asking about...

I know that our current SAN with 11 300GB 15k disks in RAID5 has rebuilt in < 3 hours...

I know it would go slower with larger 600GB 10k SAS disks...I just wanted to have some idea/concept...

Thank you...

[KJohnsonCDA]

I have 2 P2000 G3 setups.  One of them was built up with 16x 1 TB SATA drives in RAID 6.  Popping a drive on that array and rebuilding took about 18 hours. 

I have another unit with 11 x 3TB SAS drives in a single RAID 6 Array.  That takes about 36 hours to rebuild the array after a drive failure.  The rebuild times are taken from real world experience within the last 2 months.  Both arrays were under load and being used during the rebuild.