EXT errors

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

I've been getting these errors everyone so often:

NeddySeagoon · Posted: Sun Dec 17, 2017 6:47 pm Post subject:

Nicias,

Maybe all of these things, maybe none of them.

What other errors are there in dmesg?
Put it all on a pastebin site please.

The output of

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

got a ton of new errors in the last day:

https://pastebin.com/s7KVxKmR

but SMART looks fine.

NeddySeagoon · Posted: Mon Dec 18, 2017 12:15 pm Post subject:

Nicias,

There are no underlying drive errors in dmesg nor in smartclt.
If you know your backup is good, remake the filesystem and restore the backup.
If the backup was made with those filesystem errors, you don't know that its good, even if it seems to be.

Try fsck but be warned that all it does it make the filesystem metadata self consistent. It may trash your user data in the process of fixing the metadata.
That's because in the face of missing or conflicting information, it guesses and it can guess incorrectly.
All the bits that fsck doesn't know what to do with end up in /lost+found, which should always be empty.

You cannot fsck a mounted partition.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

I have done fsck as recently as a couple of weeks ago. (from a sysrescuecd usb)

This is just the system drive, it has no actual data on it, so I'm not worried about data loss. I'd clobber the whole thing and do a reinstall except for the time that would take.

I'll wipe the disk and reinstall from the last backup. Why would these errors keep popping up?

NeddySeagoon · Posted: Mon Dec 18, 2017 3:49 pm Post subject:

Nicias,

Unclean shutdows, PSU problems of some sort. Maybe even RAM issues.

Its worth a few cycles of memtest86. Be aware that memtest86 uses most of the rest of the system, so not all errors reported by memtest are due to RAM.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

I'll run memtest and see what if finds. The machine is an old laptop. It never shuts down on its own, comes unplugged, or has the power drop.

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

Memtest ran for 24 hours and found no errors.

fsck found a ton of errors on sda3. sdb1 had no errors. sda is an internal sata ssd. sdb1 is externally (usb) attached spinning rust.

Any suggestions? Bad drive? Bad motherboard/controler?

Ant P. · Watchman Joined: 18 Apr 2009 Posts: 6920

Could also be a bad cable, but any of those things would likely show up in the SMART logs.

NeddySeagoon · Posted: Wed Dec 20, 2017 11:10 am Post subject:

Nicias,

Bad SSD firmware ?
Do you use trim/discard?
There are SSDs with problem firmware where trim can erase the wrong things.

There is one famous example where LBA 0 (the boot sector) would be trimmed, making the system impossible to boot.

-- edit --

Hmm ...

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

I don't have trim or discard set.

So it seems like maybe I should get a new drive :/

NeddySeagoon · Posted: Wed Dec 20, 2017 1:26 pm Post subject:

Nicias,

I wouldn't go that far yet.

You have

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

The backup is file-level not file-system level. Doesn't that mean that if it is an accurate copy of a bad file-system that it will just have files that are screwed up, not a corrupted file-system?

So if I reformat the drive, recreate the file system and restore from backup then I might just have some bad files, not a bad file-system. In that case would doing a emerge -e world (and recompile the kernel) fix those files?

NeddySeagoon · Posted: Wed Dec 20, 2017 9:02 pm Post subject:

Nicias,

That's correct.

You run the risk that something important like glibc is broken, so you won't be able to boot, or something in the toolchain is broken, so you won't be able to build packages.
However, challenges like that can be fixed if they arise.

You would have noticed both of those particular examples already though but you get the idea.
Its possible that the restored backup will not work as expected.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

Thanks! Wish me luck!

NeddySeagoon · Posted: Wed Dec 20, 2017 9:56 pm Post subject:

Nicias,

Good luck!
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

So far everything is running smoothly.

Reformatted and reinstalled from backup, then rebuilt toolchain, kernel, and world. Now doing the gcc upgrade for PIE (and world rebuild) no fs errors yet. When this world rebuild is done I'll reboot to a live usb to check for fs errors.

In terms of trim/discard, it seems like best practice is to do that via a cron job. Is this correct?

NeddySeagoon · Posted: Fri Dec 22, 2017 5:58 pm Post subject:

Nicias,

There are divided opinions on the use of trim/discard.
Once you issue a trim command, your data can be removed by the drive at any time.
There is generally no possibility of recovering data from trimmed space.
If that might matter to you, run fstrim manually when you are sure you wont want anything back.

Beware that some drives take a long time to become ready after a fstrim.
I have one that takes over 10min. If they are online, that's fine, if you reboot, you might get a fright as the drive seems to have failed.

Personally, I have the discard option in /etc/fstab but only the installed system is on the SSD.
/home is on rotating rust, so trim/discard does not apply.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

NeddySeagoon,

There is not data on the SSD here either, so I put a daily fstrim cron job.

Thanks for all of your help. After it finished emerging, I restarted from a thumb drive. Checked the filesystems, no errors. Hopefully this fixes it.

-Nick

NeddySeagoon · Posted: Fri Dec 22, 2017 11:31 pm Post subject:

Nicias,

We don't know what happened, so cannot take any steps to stop it happening again.

All you can do is to watch for the errors recurring.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Jaglover · Posted: Sat Dec 23, 2017 12:08 am Post subject:

The hours on the drive are near to 25,000, last test was ran at 1,000.
_________________
My Gentoo installation notes.
Please learn how to denote units correctly!

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

And it's back:

Nicias · Guru Joined: 06 Dec 2005 Posts: 446

Firmware update seems to have solved the problem. No ext errors in almost two months.