Re: [gentoo-user] cryptsetup close and device in use when it is not

[Dale]

Frank Steinmetzger wrote:
> Am Wed, Jul 07, 2021 at 01:08:55PM -0500 schrieb Dale:
>
>> root@fireball / # blkid | grep dde669
>> /dev/mapper/8tb: LABEL="8tb-backup"
>> UUID="0277ff1b-2d7c-451c-ae94-f20f42dde669" BLOCK_SIZE="4096" TYPE="ext4"
>> root@fireball / # ls /dev/disk/by-uuid | grep dde669
>> 0277ff1b-2d7c-451c-ae94-f20f42dde669
>> root@fireball / #
> I followed this thread, and couldn’t remember ever having the same issue.
> But today I was bitten: It’s a 3 TB external USB drive from Intenso.
>
> Yesterday I was in the middle of a backup (it’s my main backup drive), but I
> had to sleep and so sent the machine into standby. I had to start the PC
> again a few minutes later in order to unmount an sshfs of it on another
> machine, and sent it right back to sleep.
>
> Just now I switched the PC back on and the drive was gone and off (USB
> enclosures tend to spin down the drive when USB disconnects). So I pulled
> the USB cable and plugged it back in for the drive to start and be
> rediscovered. That worked and I resumed the backup, but this enclosure has
> the nasty habit of sometimes intermittently disconnecting on its own.
>
> Its device was not gone (it usually disconnects for a tiny moment and then
> comes back, probably a USB issue), so I just tried to open it again in
> Dolphin, which gave me:
> Error unlocking /dev/sdd1: Failed to activate device: File exists
>
> $ blkid | grep luks
> /dev/mapper/luks-6a55a712-773e-4cd8-9776-fc9b6f39a998: LABEL="backup" UUID="50ed9519-cd9c-4d11-b78a-9f057b089362" BLOCK_SIZE="4096" TYPE="ext4"
>
> $ ls -l /dev/disk/by-uuid/6a55a*
> lrwxrwxrwx 10 root 2021-07-25 21:34 /dev/disk/by-uuid/6a55a712-773e-4cd8-9776-fc9b6f39a998 -> ../../sdd1
>
> $ lsblk
> NAME     MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINTS
> […]
> sdd        8:48   0   2,7T  0 disk
> └─sdd1     8:49   0   2,7T  0 part
>
> $ mount | grep -E 'luks|sdd'
> [nothing]
>
> $ cryptsetup luksClose luks-6a55a712-773e-4cd8-9776-fc9b6f39a998
> Device luks-6a55a712-773e-4cd8-9776-fc9b6f39a998 is still in use.
>
> I don’t quite like this bad habit of the enclosure, but a 3 TB drive is a 3
> TB drive. I just looked at smart to see how old it is, because it has only
> 350 hours of power-on time, but it must be at least 5 years old. And
> smartctl tells me there is a firmware update available! (for Windows, Mac
> and—lo and behold—a bootable ISO, let’s hope it works with USB sticks).
>
> Perhaps this fixes the issue. Dale, maybe you should look for the same.
>


That's interesting.  I have two different drives, can't recall but may
be the same brand.  While using UUID to mount it, it would either fail
every time or in the case of the smaller drive, fail on occasion but not
every time.  The smaller drive worked most of the time but after a
couple failures, I switched to mounting by label.  Since switching both
drives to mount by labels, neither has had a single issue.  My backups
last time went without a hitch.  I was actually planning to post that
after my next backup if nothing failed.  As it is, I think switching to
labels has fixed it. 

I've tried external drives connected by USB before and hated them.  Slow
when they do work and buggy at that.  I've had more drives go bad when
using USB enclosures than I've ever had on IDE or (e)SATA.  I've had two
drives fail after years of service that were IDE or SATA.  I have three
drives that are bricks and all of them were in USB enclosures and far
young to die.  I paid more for eSATA external enclosures and have had no
problems with drives going dead yet.  All of them have far surpassed the
drives in the USB enclosures.  Heck, this 'in use' problem is the first
issue I recall having.  Fast too.  The SMR drive not so much but the CMR
drive is as fast as what is in my system connected to the mobo itself. 

The thing about this, I have no idea why switching to labels works.  The
UUID, label and such are nothing but links to the real device.  It
should make no difference at all which one is used to mount with.  I'm
no guru or anything but it just shouldn't matter. 

Bad thing is, I don't use anything Microsoft here.  Can a drive's
firmware be updated on Linux?  I think my drives are either Seagate or
WD.  I tend to stick with those two, unless it is a really awesome
deal.  I've never updated the firmware on a drive before.  I have my
mobo and my router but not a drive. 

Dale

:-)  :-)