Do volumes unmount during file system check?

Questions about SNMP, Power, System, Logs, disk, & RAID.
Post Reply
Starting out
Posts: 13
Joined: Wed Jul 15, 2020 1:48 am
Location: Yukon, Canada

Do volumes unmount during file system check?

Post by whistlerdan » Thu Apr 22, 2021 11:47 pm

I recently got the warning message about the file system not being clean. of course, it requested to run the file system check, which I did.

On one volume, this happened quickly and completed.

My other volume, however, was suddenly unmounted. And this caused various error messages to appear because the log storage location was set to the volume that had now vanished.

I thought something was wrong, so I rebooted the NAS and then everything seemed fine.

I contacted support, and they told me that when you run the file system check, the volume must unmount to do the check. But that doesn't make sense to me because one of my volumes did not unmount, and the check was completed on that volume. And also, I swear I have run this test multiple times in the past and never seen this happen before.

I also feel that if the plan was for file system check to unmount your volume, it would explicitly tell you this, right? You are going to lose access to your files for an indeterminate amount of time if this is the case. Support actually told me it could be "up to 48 hours".

I'm just trying to find out what is normal because this will surely come up again at some point.

Know my way around
Posts: 122
Joined: Mon Aug 13, 2018 4:58 pm

Re: Do volumes unmount during file system check?

Post by syncthing » Fri Apr 23, 2021 12:53 am

a file system check usually happens on an unmounted filesystem

User avatar
Been there, done that
Posts: 682
Joined: Tue Dec 02, 2008 11:26 am
Location: Somewhere in the Great White North

Re: Do volumes unmount during file system check?

Post by jaysona » Fri Apr 23, 2021 2:36 am

A volume must be unmounted in order for a file system (e2fsck) check to be performed.

These types of check are usually required when a NAS is not powered down gracefully. Under normal use there should be no need to perform a volume check.

I have been using Linux since 1993, and I have never seen a volume check take more than a few minutes of most systems, and up to an hour on really low power CPU system that had a very large volume.

RAID scrubbing can take several hours to a couple of days to complete, but RAID scrubbing is not a volume check.
H/W: Asustor AS6604T (8Gig) / Asustor AS7010T (16Gig)
H/W: TS-219 Pro / TS-509 Pro x2 / TS-569 Pro (being decommissioned)
H/W: TS-670 Pro (i7-3770S 16Gig) / TVS-EC1080 (32Gig) TVS-871 (i7-4790S 16Gig)
O/S: Slackware 14.2 / MS Windows 7-64 (x5)
Router1: Asus RT-AC86U - Asuswrt-Merlin - 386.12
Router2: Asus RT-AC68U - DD-WRT v3.0-r39960M kongac
Router3: Linksys WRT1900AC - DD-WRT v3.0-r43028 std
Router4: Asus RT-AC66U - FreshTomato v2021.2

Misc: Popcorn Hour A-110/WN-100, Pinnacle Show Center 250HD, Roku SoundBridge Radio (all retired)
Ditched QNAP units: TS-269 Pro / TS-253 Pro (8Gig) / TS-853 Pro (8Gig) / TS-670 Pro (i7-3770S 16Gig)

Post Reply

Return to “System & Disk Volume Management”