ZFS on Linux - VDEV Warnings

[Josh_B]

Hi folks,

I am getting the following warning (found in vdev_disk.c in the ZFS source):

"WARNING: Resized bio's/dio to %d\n",bio_count". In my case, I get a warning that the value for bio/dio (bio_count) is now being set to 32.

I am fairly experienced with Linux but haven't seen this issue with any other filesystems or packages/kernels. Is there a tunable in the Linux kernel (or within the ZFS module) to increase the bio_count?

The performance is fairly good and I have not experienced any stability issues but ideally I'd like to clean this up. (Unless the medicine is worse than the ailment, of course.)

Thanks for everyone's suggestions!

 

[Josh_B]

Actually after some more reading, it appears the block size and Direct I/O writes should be aligned; I might be confused but I am pretty sure the VMFS filesystem within my ZFS-based LUN might be unaligned.

Does that seem plausible? Calling all ZFS gurus. ;-)

 

[Josh_B]

Actually after some more reading, it appears the block size and Direct I/O writes should be aligned; I might be confused but I am pretty sure the VMFS filesystem within my ZFS-based LUN might be unaligned.

Does that seem plausible? Calling all ZFS gurus. ;-)

I'm going to try and create a new LUN using the following command:

'zfs create -b 1024k -V 1G /VMs/LUN2'

I just read that VMFS5 uses a default block size of 1MB.... hopefully I can copy the VMs from the current LUNs, recreate them, and copy 'em back. ;-)

 

[MarkL]

I think you're going to find most 'ZFS Gurus' here have experience with ZFS on *Solaris and BSD.

[Edit:+I have no idea on your error, sorry..]

 

[Josh_B]

I think you're going to find most 'ZFS Gurus' here have experience with ZFS on *Solaris and BSD.

[Edit:+I have no idea on your error, sorry..]

Fair enough. I appreciate your time nonetheless in checking out my thread.