I have a large RAID5 array (3x80G) shared via NFS to allow access to photos and music from my other computers on my server. When copying a large number of files over to that system, I’m noticing a huge jump in load. I’m getting a load of 7.5 on the server right now, and I’m just copying files from the client to the server’s NFS share.
The server has the directory shared with this line in /etc/exports
/mnt/share/pictures 192.168.2.0/24(all_squash,rw,sync)
The RAID5 array is defined as
raiddev /dev/md1
raid-level 5
nr-raid-disks 3
nr-spare-disks 0
persistent-superblock 1
chunk-size 32
device /dev/hdf1
raid-disk 0
device /dev/hdg1
raid-disk 1
device /dev/hdh1
raid-disk 2
And the filesystem is mounted in fstab as
/dev/md1 /mnt/share ext3 noatime 0 0
DMA is emabled on the drives, and hdparm -Tt /dev/md1 gives me
/dev/md1:
Timing buffer-cache reads: 128 MB in 1.38 seconds = 92.75 MB/sec
Timing buffered disk reads: 64 MB in 1.70 seconds = 37.65 MB/sec
I’m also seeing 12mb/s transfer rate through the 100mb hub I have (which isn’t great, but isn’t horrible either 🙂
I’m seeing high load from raid5d, kjournald and nfsd in top and I’m guessing (hoping) that there’s a simple fix for this. It’s not a huge deal, but it’s still annoying. Anyone know why it would be doing this and how to fix it?