Question about DRBD

M

macday

Member
Mar 10, 2010
408
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16
Stuttgart / Germany
Hi guys,

I just read in a thread here, that ionice(vzdump) and other features of proxmox are only working well with the cfq-scheduler.

But the drbd-wiki tell me, that drbd-devices should be set up with the deadline-scheduler and other tweaks.

What is the best-practise ?

thx
macday
 
macday said:
Hi guys,

I just read in a thread here, that ionice(vzdump) and other features of proxmox are only working well with the cfq-scheduler.

But the drbd-wiki tell me, that drbd-devices should be set up with the deadline-scheduler and other tweaks.

What is the best-practise ?

thx
macday
Click to expand...
Hi macday,
I use DRBD with the standard pve installation without any trouble (the trouble I had before, came from the dolphin-driver... - with 10G-ethernet DRBD work rock solid).

Udo
 
You can have CFQ globally and deadline for the DRBD related block devices.

I use sysfsutils to configure scheduler on my DRBD backing devices.

sdc and sdd are my DRBD devices

/etc/sysfs.conf:
Code: 
block/sdc/queue/scheduler=deadline
block/sdc/queue/iosched/front_merges=0
block/sdc/queue/iosched/read_expire=150
block/sdc/queue/iosched/write_expire=1500
block/sdd/queue/scheduler=deadline
block/sdd/queue/iosched/front_merges=0
block/sdd/queue/iosched/read_expire=150
block/sdd/queue/iosched/write_expire=1500

I agree with Udo, 10G works great, using Infiniband cards here.
 
I this this deadline-tweaks already and ran in some errors while vzdump-ing (concurrent local writes detected...)

I´m trying this now:

echo cfq > /sys/block/sda/queue/scheduler
echo 64 > /sys/block/sda/queue/iosched/quantum
echo 0 > /sys/block/sda/queue/iosched/slice_idle
echo 1 > /sys/block/sda/queue/iosched/group_idle
echo 512 > /sys/block/sda/queue/nr_requests
Click to expand...

...for I got enterprise SAS RAID10 with DELL H700 HBA with writeback-cache.

I have also 10G Intel here.
 
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