Why does this warning comes up?

[lohmag]

Hello my Freenas has this disturbing warning
WARNING: The capacity for the volume 'VOL1' is currently at 83%, while the recommended value is below 80%.
But i created zvol with 15% of reserve to use as iSCSI volume in windows

Why does this warning comes up if it has 25% of freespace only on zvol and 15% of reserve in volume?

 

[pirateghost]

I'm not really sure I understand what you mean by "But i created zvol with 15% of reserve to use as iSCSI volume in windows"

What actual size is your ZVOL?
What actual size is your ZPOOL?

What hardware do you have?

 

[lohmag]

I read that with zfs you shiuld to reserve 15% of zpool capacity from allocation or perfomance will be reduced when it fills.
zpool list
NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT
VOL1 27.2T 22.7T 4.51T 83% 1.00x ONLINE /mnt
VOL2 13.6T 67.6M 13.6T 0% 1.00x ONLINE /mnt

zfs list
NAME USED AVAIL REFER MOUNTPOINT
VOL1 17.3T 3.11T 457K /mnt/VOL1
VOL1/.system 6.79M 3.11T 411K /mnt/VOL1/.system
VOL1/.system/cores 2.51M 3.11T 2.51M /mnt/VOL1/.system/cores
VOL1/.system/rrd 329K 3.11T 329K /mnt/VOL1/.system/rrd
VOL1/.system/samba4 914K 3.11T 914K /mnt/VOL1/.system/samba4
VOL1/.system/syslog 2.67M 3.11T 2.67M /mnt/VOL1/.system/syslog
VOL1/VOL1 17.3T 3.11T 17.3T -
VOL2 8.77T 1.95T 230K /mnt/VOL2
VOL2/VOL2 8.77T 10.7T 52.9M -

 

[Nick2253]

It's because you're above the warning threshold for capacity. 80% is the warning threshold. That's all there is.

The warning is pretty straight forward: you are using 83%, and 83%>80%.

 

[pirateghost]

And volume 1 appears to be 100% full which is very bad...

 

[gpsguy]

Note: for iSCSI use you shouldn't use more than 50% or so.

 

[lohmag]

You say if i have 10T volume i should create max 8.5T zvol and do not use more than 4.2T if it for iscsi? Wtf

 

[jgreco]

Depends on how you're using the pool. You're fighting fragmentation. Copy-on-write filesystems have a lot of difficulty coping with fragmentation. The usual answer is just to throw lots of resources at it.

https://forums.freenas.org/index.php?threads/zfs-fragmentation-issues.11818/

Code:

# zpool list storage3
NAME  SIZE  ALLOC  FREE  EXPANDSZ  FRAG  CAP  DEDUP  HEALTH  ALTROOT
storage3  10.9T  1.87T  9.00T  -  10%  17%  1.00x  ONLINE  /mnt

This system was specifically designed for VM storage. It has six three-way mirrors of 2TB drives (that's 36TB) and currently 64GB of RAM and 256GB L2ARC. Even holding things down to less than 20% capacity, it still managed to hit 10% fragmentation.

 

[lohmag]

I use iscsi as disk for backup in windows, does you post mean that samba share as network drive better option in my case?
P.S. how to find out fragmentation

Code:

zpool list VOL1
NAME   SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
VOL1  27.2T  22.5T  4.75T    82%  1.00x  ONLINE  /mnt

 

[jgreco]

I use iscsi as disk for backup in windows, does you post mean that samba share as network drive better option in my case?

No, my post doesn't mean that. The actual answer to that would be: "Depends." Backups might involve long sequential write runs, which is less stressy on ZFS than VM storage is. The sharing technology you select is more a function of what works well for your selected task.

P.S. how to find out fragmentation

Code:

zpool list VOL1
NAME   SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
VOL1  27.2T  22.5T  4.75T    82%  1.00x  ONLINE  /mnt

"zpool list" on a newer version of FreeNAS.

 

[lohmag]

I have another problem - Windows cant write on one of iscsi shares but rhere should be a lot of storage available

Code:

zfs list
NAME                  USED  AVAIL  REFER  MOUNTPOINT
VOL1                 17.2T  3.28T   724M  /mnt/VOL1
VOL1/.samba4          329K  3.28T   329K  /mnt/VOL1/.samba4
VOL1/.system         6.82M  3.28T   411K  /mnt/VOL1/.system
VOL1/.system/cores   2.51M  3.28T  2.51M  /mnt/VOL1/.system/cores
VOL1/.system/rrd      329K  3.28T   329K  /mnt/VOL1/.system/rrd
VOL1/.system/samba4   896K  3.28T   896K  /mnt/VOL1/.system/samba4
VOL1/.system/syslog  2.71M  3.28T  2.71M  /mnt/VOL1/.system/syslog
VOL1/VOL1            17.1T  3.28T  17.1T  -
---------------------------------------------------------------------------------------------
zpool list VOL1
NAME   SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
VOL1  27.2T  22.5T  4.73T    82%  1.00x  ONLINE  /mnt

But Windows showing this errors

Code:

An error was detected on device \Device\Harddisk5\DR11 during a paging operation.
Event ID 51

Windows working very slow with the drive looks like it full. What could it be?

 

[jgreco]

At 82% capacity, the system is probably struggling to find pages to allocate for whatever swapping operation Windows is trying to perform. I believe it's usually the result of a timeout, though some Windows guy will probably school me on that answer.

Windows working very slow with the drive looks like it full. What could it be?

Probably because your disk is beyond what I (and most ZFS folks) would consider "very full" for block storage use. Answered above by @gpsguy in https://forums.freenas.org/index.php?threads/why-does-this-warning-comes-up.38287/#post-231012

 

[lohmag]

I dont understand how to use nas on which 65% of space is wasted...

 

[pirateghost]

I dont understand how to use nas on which 65% of space is wasted...

You're using it incorrectly then. It's not wasting 65% of the space, but iscsi is a difficult subject in freenas.

 

[lohmag]

You're using it incorrectly then. It's not wasting 65% of the space, but iscsi is a difficult subject in freenas.

What type of share should I choose for backup media to properly use freenas?

 

[pirateghost]

Why wouldn't you use cifs?

 

[lohmag]

Becouse it's saying that only one core working with cifs shares

 

[pirateghost]

Becouse it's saying that only one core working with cifs shares

You haven't really stated what it is you want except for 'backups'. What kind of backups? What software is being used? What are you trying to accomplish?

Cifs should work just fine for backing up windows machines.

 

[lohmag]

Symantec BackupExec for files and Exchange mail backup. And backup media for a lot of wav files(20-200kb)

 

[pirateghost]

I don't see why cifs won't work with that.