On 10/7/11, Alex <mysqlstudent@gmail.com> wrote:
The only thing I haven't done from above is to use ionice on mail processes. I'm using RAID5 across three 1TB SATA3 disks,
RAID 5 is another major bottleneck there. The commonly cited write penalty for RAID 5 appears to be 4 IOPS, while RAID 1/10 is 2 IOPS. Due to the typical load on an email server with more writes than read, this become rather punishing. So you might see a major improvement simply by adding another 1TB and going for RAID 10. Personally because of that, as well as the headache of recovering from a RAID 5 disaster, I've stopped using RAID 5 especially since the cost of drives are really cheap.
I'm using deadline scheduler, the /var partition is mounted noatime, and the disk is mounted raw:
<disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/var/lib/libvirt/images/mail02.img'/> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
I meant raw disk devices rather than files e.g. <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none'/> <source dev='/dev/server02_vg1_2tb/lv_vm03_swap'/> <target dev='vdb' bus='virtio'/> </disk> This eliminates one layer of filesystem overheads.
How do I configure BIND to ignore TTLs and keep everything for five minutes, as suggested?
I'm not too sure about this sorry.