Hi, Seth,
Seth Bardash wrote:
We build a storage unit that anyone using Centos can build. It is based on the 3ware 9750-16 controller. It has 16 x 2 TB Sata 6 gb/s disks. We always set it up as a 15 disk RAID 6 array and a hot spare. We have seen
Interesting. We're still playing with sizing the RAID sets and volumes. The prime consideration for this is that the filesystem utils still have problems with > 16TB (and they appear to have been saying that fixing this is a priority for at least a year or two <g>), so we wanted to get close to that.
This afternoon's discussion has me with 2 17-drive RAID sets and a 6; on that, one volume set each, which gives us 30TB usable on the two large RAID sets and 8TB usable on the small one, all RAID 6.
multiple instances were the A/C has gone off but the customer's UPS kept the systems running for an hour or two with no cooling. Once the ambient temperature goes above 40C you are stressing all the disks in the array. I ramble about this BECAUSE we have seen many RAID 5 arrays fail while rebuilding with a hot spare and then loose all the data.
That's not a problem for us - we've got two *huge* units in the server room, er, computer lab that this RAID box is in. <snip>
Also the rebuild time for a 50 TB array is about 12 hours while the array is in use and online. But during this time there is little or no degradation in performance.
THANK YOU. I'll forward this email to my manager and the other admin - it's really helpful to know this, even if it isn't your box.
The down side is the cost of the controller. If anyone has questions about this I would be glad to answer them off line : at seth at integratedsolutions dot org.
What came with this are QLogic FC HBAs for the server.
mark