OS: Ubuntu 14.04 LTS Software Raid10: 4x120Gb Intel 530 SSDs Server: HP ProLiant DL160 G6 FS: md0: ext4/ md1:swap
Test is made on fresh new install, before making any change to some package or reboot.
Writing speed decreased to the a normal SSD write speed (in my case).
Bellow I add the stats/commands I performed.
dd if=/dev/zero of=test bs=1048576 count=2048
2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 1.79013 s, 1.2 GB/s
dd if=test of=/dev/null bs=1048576
2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 0.376622 s, 5.7 GB/s
Everythig is looking good so far. Now I took out and put back in one of the disks:
mdadm --fail /dev/md0 /dev/sda1
mdadm --remove /dev/md0 /dev/sda1
mdadm --fail /dev/md1 /dev/sda2
mdadm --remove /dev/md1 /dev/sda2
mdadm --add /dev/md0 /dev/sda1
mdadm --add /dev/md1 /dev/sda2
After rebuilding the array:
dd if=/dev/zero of=test bs=1048576 count=2048
2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 9.5621 s, 225 MB/s
dd if=test of=/dev/null bs=1048576
2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 0.375301 s, 5.7 GB/s
My arrays look like this:
cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md0 : active raid10 sdc1[2] sdb1[1] sda1[4] sdd1[3]
195177472 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
md1 : active raid10 sdd2[5] sda2[4] sdc2[2] sdb2[1]
39095296 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
I don't know where to start now. Do I miss to set some flag or something?