Fedora Linux Support Community & Resources Center

Go Back   FedoraForum.org > Community Lounge > Reviews, Rants & Things That Make You Scream
FedoraForum Search

Forgot Password? Join Us!

Reviews, Rants & Things That Make You Scream The place for you to submit reviews of all those applications you use with Fedora. The Devs probably aren't listening, but some times you've just GOT to blow off steam or sing its praises.

Thread Tools Search this Thread Display Modes
Old 14th July 2017, 07:56 PM
John Alien Offline
Registered User
Join Date: Jul 2017
Location: North America
Posts: 1
Data loss on btrfs!!

So it finally happened. I've seen 0 byte files turn up here and there, the odd image which can't be opened where I was almost sure it used to be fine.

So what happened? chmod -R on a directory and the directory went from 28gb to 1.5gb! Now I have a lot of 0 byte files in there which were not 0 byte files just seconds before, so I am sure it was chmod which is responsible, guessing in part with it being a btrfs file system.

Is chmod not to be used on a btrfs filesystem? I haven't read much documentation and have made up for my ignorance by keeping 2+ backups of everything, so I'm doing fine at the moment. I read something about btrfs working great, until it doesn't. Meaning it is so functional and robust (and fault tolerant!) is seems like there isn't anything wrong with it. Except people do run into problems with it. I'm thinking of turning a couple of my backup drives into ext4 or jfs. That way it won't all be btrfs.

Reply With Quote
Old 14th July 2017, 09:46 PM
dd_wizard's Avatar
dd_wizard Offline
Registered User
Join Date: Sep 2009
Posts: 2,113
Re: Data loss on btrfs!!

I've been using btrfs for years, with zero data loss. Also, I can't think of any reason why chmod would cause data loss, even with the -R option. Unless your command was mistyped? Do you have the command in history so you can look at it by editing ~/.bash_history? I do remember a find command typed in by a co-worker that truncated most of the root file system to 0B files. He used the exec option to find that copied the files to themselves when they were located by find. Backups rock!

Reply With Quote
Old 14th July 2017, 09:49 PM
dcrdev Offline
Registered User
Join Date: Oct 2015
Location: Sheffield UK
Posts: 85
Re: Data loss on btrfs!!

I'm pretty sure the filesystem layer is stable, I thought it was only the RAID checksumming and parity that was unstable with certain configurations; I'm no expert though.

I can't see how chmod would result in a data loss, are you sure you didn't somehow make the files immutable? Could you try "chattr -R -i /some/directory" and see i that works?

Otherwise I would try a btrfs scrub and then a reboot. I have been using btrfs in RAID1 for about 1 1/2 years and have done countless chmod operations, never had that issue.
Reply With Quote
Old 17th July 2017, 02:43 PM
tim8723 Offline
Registered User
Join Date: Mar 2017
Location: USA
Posts: 36
Re: Data loss on btrfs!!

What dd_wizard said. Every problem I have had with btrfs over at least 5 years of constant use has been self-inflicted, i.e., mistakes on my part.

Reply With Quote
Old 17th July 2017, 04:42 PM
lsatenstein Offline
Registered User
Join Date: Jun 2005
Location: Montreal, Que, Canada
Posts: 4,349
Re: Data loss on btrfs!!

I can't use my $HOME with btrfs as my favourite Gnome extension locks up Gnome and itself completely, needing a root level intervention to remove that extension Taskbar by Zpdyr. I am slowly tying to follow his javascript and to discover where he stores his data.

I read where btrfs is preferred for SSD's and thats why I am making use of btrfs.
Leslie in Montreal

Interesting web sites list
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
btrfs-convert tool corrupts data tkalfaoglu Using Fedora 0 9th September 2016 10:56 AM
BTRFS data corruption on unclean shutdown empire Using Fedora 0 16th May 2013 10:20 PM
Btrfs and data loss dth4h Linux Chat 12 28th October 2011 11:07 PM
Data Loss > Big Problem! smithxi Using Fedora 13 26th November 2006 02:18 AM

Current GMT-time: 07:28 (Wednesday, 18-10-2017)

TopSubscribe to XML RSS for all Threads in all ForumsFedoraForumDotOrg Archive

All trademarks, and forum posts in this site are property of their respective owner(s).
FedoraForum.org is privately owned and is not directly sponsored by the Fedora Project or Red Hat, Inc.

Privacy Policy | Term of Use | Posting Guidelines | Archive | Contact Us | Founding Members

Powered by vBulletin® Copyright ©2000 - 2012, vBulletin Solutions, Inc.

FedoraForum is Powered by RedHat