Hi, I just replaced Slackware64 14.1 running on my office's HP Proliant Microserver with a fresh installation of CentOS 7. The server has 4 x 250 GB disks. Every disk is configured like this : * 200 MB /dev/sdX1 for /boot * 4 GB /dev/sdX2 for swap * 248 GB /dev/sdX3 for / There are supposed to be no spare devices. /boot and swap are all supposed to be assembled in RAID level 1 across 4 disks. The / partition is supposed to be assembled in RAID level 5 across 4 disks. With Slackware I created the arrays manually like this: # mdadm --create /dev/md1 --level=1 --raid-devices=4 --metadata=0.90 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 # mdadm --create /dev/md2 --level=1 --raid-devices=4 --metadata=0.90 /dev/sda2 /dev/sdb2 /dev/sdc2 /dev/sdd2 # mdadm --create /dev/md3 --level=5 --raid-devices=4 --metadata=0.90 /dev/sda3 /dev/sdb3 /dev/sdc3 /dev/sdd3 Using this setup, I had 650 MB of disk space on /dev/md3. Now I tried to do the same thing with CentOS 7. Everything seemed to work at first, but here's what I got now: [root at nestor:~] # df -h Sys. de fichiers Taille Utilisé Dispo Uti% Monté sur /dev/md127 226G 1,1G 213G 1% / devtmpfs 1,4G 0 1,4G 0% /dev tmpfs 1,4G 0 1,4G 0% /dev/shm tmpfs 1,4G 8,5M 1,4G 1% /run tmpfs 1,4G 0 1,4G 0% /sys/fs/cgroup /dev/md125 194M 80M 101M 45% /boot /dev/sde1 917G 88M 871G 1% /mnt The root partition (/dev/md127) only shows 226 G of space. So where has everything gone? [root at nestor:~] # cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md125 : active raid1 sdc2[2] sdd2[3] sdb2[1] sda2[0] 204736 blocks super 1.0 [4/4] [UUUU] md126 : active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0] 4095936 blocks super 1.2 [4/4] [UUUU] md127 : active raid5 sdc3[2] sdb3[1] sdd3[4] sda3[0] 240087552 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU] bitmap: 0/1 pages [0KB], 65536KB chunk unused devices: <none> [root at nestor:~] # mdadm -D /dev/md127 /dev/md127: Version : 1.2 Creation Time : Wed Feb 18 06:49:01 2015 Raid Level : raid5 Array Size : 240087552 (228.97 GiB 245.85 GB) Used Dev Size : 80029184 (76.32 GiB 81.95 GB) Raid Devices : 4 Total Devices : 4 Persistence : Superblock is persistent Intent Bitmap : Internal Update Time : Wed Feb 18 08:04:26 2015 State : active Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : left-symmetric Chunk Size : 512K Name : localhost:root UUID : cfc13fe9:8fa811d8:85649402:58c4846e Events : 4703 Number Major Minor RaidDevice State 0 8 3 0 active sync /dev/sda3 1 8 19 1 active sync /dev/sdb3 2 8 35 2 active sync /dev/sdc3 4 8 51 3 active sync /dev/sdd3 Apparently no spare devices have been created. So why do I only have 226 GB of disk space under CentOS, when I had roughly 650 GB under Slackware? I'm a bit lost here. Any suggestions? Cheers, Niki -- Microlinux - Solutions informatiques 100% Linux et logiciels libres 7, place de l'église - 30730 Montpezat Web : http://www.microlinux.fr Mail : info at microlinux.fr Tél. : 04 66 63 10 32