Bug 86064 - Kernel oops with very large number of software RAID arrays
Summary: Kernel oops with very large number of software RAID arrays
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: kernel
Version: 7.3
Hardware: i686
OS: Linux
Target Milestone: ---
Assignee: Arjan van de Ven
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2003-03-13 13:37 UTC by Andrew Rechenberg
Modified: 2007-04-18 16:51 UTC (History)
0 users

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2004-01-31 00:59:37 UTC

Attachments (Terms of Use)
Patch to convert /proc/mdstat to use seq_file (14.82 KB, patch)
2003-03-13 13:41 UTC, Andrew Rechenberg
no flags Details | Diff

Description Andrew Rechenberg 2003-03-13 13:37:17 UTC
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0)

Description of problem:
When using a large number of Linux software RAID arrays I receive a kernel 
OOPS.  With some help from users on the kernel mailing list and the linux-raid 
list we have determined that /proc/mdstat is overflowing it's 4k page and 
overwriting some other part of kernel memory causing the OOPS.

This problems appears to mainfest itself around 24-27 RAID1 arrays.  

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Boot with 2.4.18-26.7.x
2. Create a large number of software RAID1 arrays.
3. Watch the kernel go bye-bye

Actual Results:  Kernel OOPS in do_try_to_free_pages

Expected Results:  No OOPS

Additional info:

Comment 1 Andrew Rechenberg 2003-03-13 13:41:00 UTC
Created attachment 90582 [details]
Patch to convert /proc/mdstat to use seq_file

The attached patch seems to resolve the OOPS I was seeing.  I currently have 52
SCSI disks in 26 RAID1 arrays and one RAID0 stripe across those.  It has been
running successfully on test hardware under load for approximately 24 hours

Comment 2 Andrew Rechenberg 2004-01-31 00:59:37 UTC
As an FYI, the 2.4.20-x series of errata kernels seem to have switched
to seq_file for md.  

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