Why my Linux server ext3 filesystem go read-only?
From my mailbag:
We have 5 Dell server collocated running CentOS 4.x and 5.x server operating system. Sometime my file system (ext3) goes read-only. I’d like to know what could be causing such a problem?
My guess:
a) Hardware problem / hard disk problem, check harddisk for errors.
b) High disk I/O aka busy I/O retry error can mark low level disk call as failed. This will force ext3 to go into read only mode.
c) High disk I/O on SAN
d) SAN is not configured properly for the path failover.
In all sort of problems ext3 goes read-only to protect the filesystem and further damage. If you are using VMWARE, check out official webpage to download SCSI patches or workaround for vmware problems.
So what could be causing the file system on Linux go read-only?
Apart from above generic problem, any other error can trigger filesystem on Linux go read only. I hope our reader / seasoned Linux admin can help to answer this question. Please share the experiences and advice in the comments.
Want to stay up to date with the latest Linux tips, news and announcements? Subscribe to our free e-mail newsletter or full RSS feed to get all updates.
You can Email this page to a friend.
You may also be interested in...
- Shell scripting (BASH) : How to accept password in script
- Setup your own name servers with ISPConfig and GoDaddy domains
- Why doesn’t Linux need defragmenting?
- MySQL Database Runs 60 to 90 Percent Faster on Solaris 10 Than on Red Hat Linux
- History and Culture of Unix Programming - The Art of Unix Programming
Discussion on This Article:
Leave a Reply
We encourage your comments, and suggestions. But please stay on topic, be polite, and avoid spam. Thank you very much for stopping by our site!
Tags: CentOS, check_harddisk, disk_problem, ext3_filesystem, failover, filesystem, hardware_problem, high_disk_i_o, read-only_filesystem, san_path_failover, vmware ~ Last updated on: August 28, 2007



RAID going in degraded mode, the fs may detect that and the server can get in read only.
I have similar issues with RHEL 4ES U3 or U4. Did you get this issue(s) resolved yet? Thanks.
This is a bug in the Linux kernel. It apparently is fixed in kernels as of 2.6.22. Also, I *think* it has been back-ported to some earlier kernels. For example CentOS 5.1 (and RHEL 5.1 for that matter) supposedly have it fixed as well. I was commonly seeing it in CentOS 5 virtual machine running on VMWare. Here is their Knowledge Base article for more info.
Although that article is targeted for virtual machines, apparently the kernel bug affected Linux running on real hardware as well.