Re: 12 TB btrfs file system on virtual machine broke again

From: Christian Wimmer <telefonchris@icloud.com>
To: Chris Murphy <lists@colorremedies.com>
Cc: Qu Wenruo <quwenruo.btrfs@gmx.com>, Qu WenRuo <wqu@suse.com>,
	Anand Jain <anand.jain@oracle.com>,
	"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: 12 TB btrfs file system on virtual machine broke again
Date: Sun, 5 Jan 2020 16:18:19 -0300	[thread overview]
Message-ID: <CC877460-A434-408F-B47D-5FAD0B03518C@icloud.com> (raw)
In-Reply-To: <CAJCQCtQAFRdutyVOt7JALtVsn-EeXhzNYYjdKpmS1Ts_6-6nMA@mail.gmail.com>

> On 5. Jan 2020, at 15:50, Chris Murphy <lists@colorremedies.com> wrote:
> 
> On Sun, Jan 5, 2020 at 7:17 AM Christian Wimmer <telefonchris@icloud.com> wrote:
>> 
>> Seems that I am using fstrim (I did not know this, what is it?):
> 
> Frees unused blocks from underlying storage: in the case of sparse
> files it punches holds, for thin provisioning it frees logical extents
> back to the pool, and for real physical SSDs it informs the firmware
> those blocks are no longer used and can be garbage collected.
> 
> Most bugs in this area have either been fixed by firmware updates by
> manufacturers for the SSD, or they've been blacklisted in the kernel
> so that FITRIM is a no op.
> 
> 
>> 
>> BTW, sda2 is here my root partition which is practically the same configuration (just smaller) than the 12TB hard disc
>> 
>> 2020-01-03T11:30:47.479028-03:00 linux-ze6w kernel: [1297857.324177] sda2: rw=2051, want=532656128, limit=419430400
>> 2020-01-03T11:30:47.479538-03:00 linux-ze6w kernel: [1297857.324658] BTRFS warning (device sda2): failed to trim 1 device(s), last error -5
>> 2020-01-03T11:30:48.376543-03:00 linux-ze6w fstrim[27910]: fstrim: /opt: FITRIM ioctl failed: Input/output error
>> 2020-01-03T11:30:48.378998-03:00 linux-ze6w kernel: [1297858.223675] attempt to access beyond end of device
>> 2020-01-03T11:30:48.379012-03:00 linux-ze6w kernel: [1297858.223677] sda2: rw=3, want=421570540, limit=419430400
> 
> Yeah that's a problem. That may not be *the* problem, but there is
> confusion here. What is /dev/sda?

/dev/sda is the hard disc file that holds the \x10Linux:

#fdisk -l
Disk /dev/sda: 256 GiB, 274877906944 bytes, 536870912 sectors
Disk model: Suse 15.1-0 SSD 
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 186C0CD6-F3B8-471C-B2AF-AE3D325EC215

Device         Start       End   Sectors  Size Type
/dev/sda1       2048     18431     16384    8M BIOS boot
/dev/sda2      18432 419448831 419430400  200G Linux filesystem
/dev/sda3  532674560 536870878   4196319    2G Linux swap

This file is located on the SSD of my MAC Mini. /dev/sda2 is formatted with btrfs.

> This is a virtual drive inside the
> guest VM? And is backed by a file on the Promise storage? What about
> /dev/sdb? Same thing? You're only having a problem with /dev/sdb,
> which contains a Btrfs file system.

Actually I have only a problem with the /dev/sdb which is a hard disc file on my Promise storage. The sda2 complains but boots normally.

Regarding any logs. Which log files I should look at and how to display them?
I looked at the /var/log/messages but did not find any related information.

Chris