Hello, I just upgrade my Unraid server from 6.8.3 to 6.9.2

 

I know that there is a new feature to create multiple pools but something I feel confuse.

 

Seems only "Array Device" part got parity check disk?

 

If I create a new pool with 4 disk inside and then set to RAID5, it is a real RAID5? (Because that is no real RAID function in 6.8.3)

And this RAID5 is isolated from the "parity disk" under "Array Device"?

 

Currently I got 10 x 12 TB disks and I would like to break them as follow:

 

POOL1: 4 x 12 TB in RAID5 (i.e. able to lose on disk and recovery)

POOL2: 4 x 12 TB in RAID5 (i.e. able to lose on disk and recovery)

POOL3: 1 x 12 TB

POOL4: 1 x 12 TB

 

So, I only need to do this under "Pool Device" section and totally ignore anything in "Array Device"?

 

Thanks and forgive me if I am asking stupid question, I still a newbie on the new system.

Edited April 21, 20215 yr by Symadic William

Unraid currently only supports one array, pools use btrfs, and can use any of the available btrfs profiles, including raid5/6, but note that those are still considered experimental.

Thanks Jorge. Do you mean that such "RAID5" is not that safe 😅?

 

Some forum also say that Btrfs "bugs" cause RAID5/6 not stable

1 hour ago, Symadic William said:

Do you mean that such "RAID5" is not that safe 😅?

There are still some issues, but it can be used, I have several btrfs RAID5 pools, but also have good backups.

6 hours ago, JorgeB said:

There are still some issues, but it can be used, I have several btrfs RAID5 pools, but also have good backups.

Thanks for your advice 😀

I am now adding  a 4 x 12TB RAID pool 1st, the others will remain as normal array.

 

Anything I need to pay attention on using btrfs RAID5?

Monitor the pool for errors, though this is important for any btrfs pool, pool should be immediately scrubbed after any unclean shutdown, but keep in mind that scrub on raid5/6 pools are painfully slow, unless you're using SSDs, so be prepared for that.

Thanks Jorge, my parity check is done. However, I found that only "Array Disk" can be add to "Shares".

The "Pool" disk seems cannot be show up in "Shares". Did I missed something?

 

Pools are still part of the user shares, any top folder in a pool is a share.

A pool is (potentially) part of a share when you select that pool within the share setting.   Whether it actually gets used depends on what option you select from the Use cache pool setting.

 

I tried to select "only" under  "Use cache pool (for new files/directories)" in "Shares" and now able to access the share folder via SMB.

 

How ever the performance is really terrible @o@"

 

Starting: 110 MB/s then drop down to 30-45 MB /s

 

Is that normal? I am using 10 Gb LAN right now

That mostly depends on the hardware used and pool config, I have a 6 disk RAID5 pool and get around 350MB/s sustained writes.

 

 

1 hour ago, JorgeB said:

That mostly depends on the hardware used and pool config, I have a 6 disk RAID5 pool and get around 350MB/s sustained writes.

 

 

Feel really strange, I build a single disk pool with one of my SSD, again write speed drop down to 4x MB/s but read speed can keep at 600 MB/s.

How can I check what's going on?

 

My build is:

============

Intel® Core™ i5-9500T CPU @ 2.20GHz

ASRock B365 Phantom Gaming 4
American Megatrends Inc., Version P4.30
BIOS dated: Thu 14 May 2020 12:00:00 AM PDT

32 GB DDR4 Memory

LSI SAS 9207-8i SAS/SATA 6Gb PCI-E 3.0 SAS HBA

WD HC520 12 TB Harddisk x 8

Intel X520-DA2 10Gbs LAN Card
 

 

sydisk-diagnostics-20210423-2136.zip

 

Edited April 23, 20215 yr by Symadic William

Can't download diags, forum problem, what model SSD?

2 minutes ago, JorgeB said:

Can't download diags, forum problem, what model SSD?

WD Black SN750 NVMe

 

I tried, no wonder what type of harddisk, array, pool setting, the writing speed keep around 100 MB/s in frist 15-20 second and then drop down to 4XMB /s

 

I uploaded a copy of log file to google drive as follow:

https://drive.google.com/file/d/1y6975SxT02Bg6fzwXbsqE9bspCAKPJEB/view?usp=sharing

 

50 minutes ago, Symadic William said:

the writing speed keep around 100 MB/s in frist 15-20 second

This should be much faster with 10GbE, while it's caching to RAM.

 

51 minutes ago, Symadic William said:

and then drop down to 4XMB /s

But this suggests it's not just a network issue, in any case I would start with a single stream iperf test.

1 minute ago, JorgeB said:

This should be much faster with 10GbE, while it's caching to RAM.

 

But this suggests it's not just a network issue, in any case I would start with a single stream iperf test.

 

Thanks Jorge, I also hear about iperf from other post, however I don't know how to use it.

 

I downloaded the program to my Win10 PC, seems I need to type some command things.

Another silly question it, in some post, I find that iperf is runnning in Unraid.

 

What should I do in my case? Run from Win10 client PC or Unraid or both 😅?

 

Many Thanks 😃

 

My information as follow:

 

That's not very good, but not what's limiting speeds to <100MB/s, did you try transferring to a disk share to see if it's any different?

42 minutes ago, JorgeB said:

That's not very good, but not what's limiting speeds to <100MB/s, did you try transferring to a disk share to see if it's any different?

 

OMG 😶When I activated disk share, the speed write-in changed to around 8X - 100MB/s

How come @@"

User shares always have some overhead, though some users feel it much more than others.

18 hours ago, JorgeB said:

User shares always have some overhead, though some users feel it much more than others.

Thanks a lot, Jorge 👍

 

I rebuild my RAID5 with original plan (now with disk share), I can now have 4xx - 5xx write-in speed~~~ 😃

 

Never imagine the coding in "User share" will cause much performance issue: https://blog.insanegenius.com/2020/04/25/unraid-user-share-vs-disk-share-smb-performance/