OK todays problem. I have a HP N54L Microserver running centos 6.5.
In this box I have a 3x2TB disk raid 5 array, which I am in the process of extending to a 4x2TB raid 5 array. I've added the new disk --> mdadm --add /dev/md0 /dev/sdb And grown the array --> mdadm --grow /dev/md0 --raid-devices=4 Now the problem the resync speed is v slow, it refuses to rise above 5MB, in general it sits at 4M. from looking at glances it would appear that writing to the new disk is the bottle neck, /dev/sdb is the new disk. Disk I/O In/s Out/s md0 0 0 sda1 0 0 sda2 0 1K sdb1 3.92M 0 sdc1 24.2M 54.7M sdd1 11.2M 54.7M sde1 16.3M 54.7M I partitiioned the disk with --> parted -a optimal /dev/sdb [root@nas ~]# parted -a optimal /dev/sdb GNU Parted 2.1 Using /dev/sdb Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) p Model: ATA ST2000DM001-1E61 (scsi) Disk /dev/sdb: 2000GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 2000GB 2000GB primary ntfs raid There is no ntfs filesystem on the disk, I've still not worked out how to remove that flag. I've followed the article here --> http://www.cyberciti.biz/tips/linux-raid-increase-resync-rebuild-speed.html to attempt to speed it up but no joy. iostat -x -m5 implies that the disk is at 100% when writing at 4.2 MB/s, so there's something very wrong somewhere. Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util sdb 0.00 711.20 0.00 8.40 0.00 4.20 1024.00 97.42 9441.55 119.05 100.00 Any Ideas what I've done wrong? parted output [root@nas ~]# parted -l Model: ATA ST31000528AS (scsi) Disk /dev/sda: 1000GB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 525MB 524MB primary ext4 boot 2 525MB 1000GB 1000GB primary lvm Model: ATA ST2000DM001-1E61 (scsi) Disk /dev/sdb: 2000GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 2000GB 2000GB primary ntfs raid Model: ATA ST2000DM001-9YN1 (scsi) Disk /dev/sdc: 2000GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 2000GB 2000GB primary raid Model: ATA WDC WD25EZRS-00J (scsi) Disk /dev/sdd: 2500GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 2000GB 2000GB primary ntfs raid Model: ATA ST2000DL001-9VT1 (scsi) Disk /dev/sde: 2000GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 2000GB 2000GB primary raid -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
