Updating my own post iostat shows /dev/sdb is at 100% transferring at 4MB/S
So what limits a disk to 4MB/S???
On 18 March 2014 08:43, Jeff Allison <jeff.allison at allygray.2y.net>
wrote:> 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 at 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.
>
> Any Ideas what I've done wrong?
>
> parted output
>
> [root at 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