Arch Linux

luthis

Member

Registered: 2016-02-12

Posts: 8

Is it ok to reboot during intial mdadm sync?

I just finished following the wiki on creating a RAID1 array, not a boot drive.

I think some cables may be loose in my box because when I plug in another HDD into the external case SATA hotswap mount, I can't see it in fdisk -l. It's in the fstab so it should just mount automatically, but OS can't see it.

Is it ok to reboot before the first sync has completed across the drives?

If not, can I speed it up by changing stripe_cache_size?

It's now syncing, and says 21 hours. Which isn't a bad speed I guess for the size, at speed=205629K/sec, but this is the first time I've done this.

How would I find the stripe_cache_size? It seems like a different thing to stripe width.

https://www.itsfullofstars.de/2019/02/i … sync-rate/

says:

You set the size of stripe_cache_size for each RAID device (mdX). In case your RAID is md0:

echo 32768 > /sys/block/md0/md/stripe_cache_size

But it doesn't say how to confirm what stripe_cache_size should be, and what to do after changing it.

Thanks! Sorry if this should be in the Newbie corner.

frostschutz

Member

Registered: 2013-11-15

Posts: 1,417

Re: Is it ok to reboot during intial mdadm sync?

You can reboot, it might start over the sync from 0 though.

luthis

Member

Registered: 2016-02-12

Posts: 8

Re: Is it ok to reboot during intial mdadm sync?

Thanks. Ha, I knew I had seen your username on a post while researching:

https://unix.stackexchange.com/question … king-stuck