From a837da06ef18cb8abfb175ba86dcb1f2b05bb558 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 12 Oct 2016 13:44:41 +0300 Subject: [PATCH] scylla_raid_setup: increase chunk size The current chunk size of 256 gives a 50% probability of a 128k read or write getting split into two accesses. This reduces efficiency and increases latency. Change the chunk size to 1MB, with a 12% probability of cross-member access. Message-Id: <1476269082-2473-1-git-send-email-avi@scylladb.com> --- dist/common/scripts/scylla_raid_setup | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/dist/common/scripts/scylla_raid_setup b/dist/common/scripts/scylla_raid_setup index 0229cfd8a1..08fe306192 100755 --- a/dist/common/scripts/scylla_raid_setup +++ b/dist/common/scripts/scylla_raid_setup @@ -60,7 +60,7 @@ if [ "$NAME" = "Ubuntu" ]; then else yum -y install mdadm xfsprogs fi -mdadm --create --verbose --force --run $RAID --level=0 -c256 --raid-devices=$NR_DISK $DISKS +mdadm --create --verbose --force --run $RAID --level=0 -c1024 --raid-devices=$NR_DISK $DISKS blockdev --setra 65536 $RAID mkfs.xfs $RAID -f echo "DEVICE $DISKS" > /etc/mdadm.conf