Hi, I'm having some problems getting decent nfs performance from some MD1220s connected to an R710. Here's a summary of the setup:
3 x MD1220 each with 24 x 500GB 7.2k SAS disk All connected to a Perc H800 in an R710. At present I have a single RAID60 volume with three spans of 23 disks, so each array holds one span plus a hot standby. Stripe element size is 64k. I'm testing the performance with: iozone -l 1 -u 1 -r 4k -s 10g -e and getting write performance of: Direct to filesystem: 1076 MB/s nfs via loopback interface: 217 MB/s nfs via IPoIB: 38 MB/s nfs via Ethernet: 24 MB/s Based on testing other systems I would expect the nfs over Ethernet to be around 100MB/s (ie saturating the GigE link) and the nfs over IPoIB to be higher than that. I've tested the network links with nttcp and there don't appear to be any problems. I've tried various filesystems (ext3, ext4, xfs) but this didn't have a significant effect. I'm wondering: 1) Should the stripe size be smaller? Given that the nfs max block size is 32KB each write is going to be less than one stripe..? 2) Is there a better way of arranging the disks? Given that I want the dual parity I'm more or less stuck with some form of RAID 6, but I could have more spans or create separate volumes and stripe them with LVM. I'm happy to test different configurations but given the time needed to reinitialise the array it would be good to get some pointers first... Any thoughts would be appreciated. Thanks, Rob _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
