Snapraid outofparity error

molnart · Nov 2nd 2017

i was trying to set up snapraid for my config (3x 3 TB disks, 2 drives filled with approx 3,5 TB data). however when attempting an initial sync i am getting an outofparity error, complaining there is not enough space for parity. the snapraid config generated by omv looks like this. any idea what could be wrong?

Code

# this file was automatically generated from
# openmediavault Erasmus 3.0.90
# and 'openmediavault-snapraid' 3.7.2


block_size 256
autosave 10
#####################################################################
# OMV-Name: Snapraid  Drive Label: Snapraid
parity /srv/dev-disk-by-label-Snapraid/snapraid.parity


#####################################################################
# OMV-Name: Data1  Drive Label: Data1
content /srv/dev-disk-by-label-Data1/snapraid.content
disk Data1 /srv/dev-disk-by-label-Data1


#####################################################################
# OMV-Name: Data2  Drive Label: Data2
content /srv/dev-disk-by-label-Data2/snapraid.content
disk Data2 /srv/dev-disk-by-label-Data2


exclude *.bak
exclude *.unrecoverable
exclude /tmp/
exclude lost+found/
exclude .content
exclude aquota.group
exclude aquota.user
exclude snapraid.conf

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molnart · Nov 25th 2017

any idea what can be wrong? snapraid was the main reason i choose OMV over xpenology, and if i cannot get it work all the time i spent with data migration was useless...

Nibb31 · Nov 25th 2017

Is there anything else on the parity drive ?

molnart · Nov 25th 2017

no, it's empty formated freshly. i even tried to exclude a folder with contains smaller files from parity. basically i get the outofparity error immediately after attempting sync, so it's not like it's syncing for minutes than gets ouf of parity

edit: after searching the snapraid forum once again for solution i found this thread https://sourceforge.net/p/snap…/1677233/thread/4a57bd19/ it seems this is a bug in snapraid, i have installed the beta version and syncing finally works

jollyrogr · Nov 27th 2017

You didn't mention in your posts, but are you using BTRFS? Looking at the linked thread, that seems to be the issue.

I've had zero issues with snapraid on ext4.

molnart · Nov 27th 2017

yes, i am on btrfs. what sync speeds are you getting with ext4? my initial sync is running for more than 30 hours now, with current speed 19 MB/s. On SnapRaid forum some users are reporting speeds ove 1000 MB/s (but with 8+ drives)

jollyrogr · Nov 27th 2017

Just to give you some idea of my system configuration,
I have 4 WD red drives and 1 WD gold. 3 data and 2 parity, all 4TB drives. The reds are 5400 rpm and the gold is 7200. I typically run 200-400 MB/s during sync. I use the prehash option on sync as well. Also, CPU is a Pentium G4560, 16GB of ram, drives are connected to a Supermicro SAS card.

When I initially created my snapraid pool, with 2 data and 2 parity drives, the data drives weren't completely full and it took something like 9 hours to sync. (that was without prehash).

I've recently had to replace and rebuild drives and it takes like 9-12 hours per drive. So it's not a fast process, but I think comparable to a raid-6 rebuild and it's nice to know the data is fairly secure.

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