Synology NAS – How to speed up expanding drive

If you are like me bought a NAS drive and want to build up storage over time due to the high expense of hard drives. The best way is to start off with 2 Hard disks as Raid 1. Then if you have enough money later on to buy the 3rd Expanding your 3rd drive a Raid 5. Depending how big your hard drives this process of expanding with Synology NAS can be a long process which can take days before you can see changes. I understand why, because anyone on your network will not be interrupted if the server is down, So it will be business as usual. But what if you need the extra space urgently hence the purchase of the third drive? Well, you come to the right place. Here is how to speed up expanding NAS.

Open terminal on you mac Putty for windows,

Type in the following to see progress:

cat /proc/mdstat

You should see something like this:

Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md3 : active raid5 sdc6[2] sdb6[0] sda6[1]
7657726592 blocks super 1.2 level 5, 64k chunk, algorithm 2 [3/3] [UUU]
[============>........] reshape = 61.6% (4722524224/7657726592) finish=402.6min speed=121486K/sec

md0 : active raid1 sdc1[2] sda1[0] sdb1[1]
2490176 blocks [4/3] [UUU_]

Here is what you need to look for:

reshape = 61.6% (4722524224/7657726592) finish=402.6min speed=121486K/sec

If you go here and type in the mins to finish you can work out how long roughly to complete expanding process.

The first this you need to do is switch over to ‘root’ user. To do this type in:

Sudo -i

Next set speed NAS speed

speed_limit_min
cat /proc/sys/dev/raid/speed_limit_min
10000

cat /proc/sys/dev/raid/speed_limit_max
20000

cat /sys/block/md3/md/stripe_cache_size
256

Copy and paste the following make increases:

echo 250000 > /proc/sys/dev/raid/speed_limit_min

echo 250000 > /proc/sys/dev/raid/speed_limit_max

echo 32768 > /sys/block/md3/md/stripe_cache_size

finally checkout the speed now and on your Resource monitor gui:

cat /proc/mdstat