Bug 168499 - EXT3 filesystem writes are half slower than reads during backup and restore
Summary: EXT3 filesystem writes are half slower than reads during backup and restore
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Red Hat Enterprise Linux 3
Classification: Red Hat
Component: kernel
Version: 3.0
Hardware: i386
OS: Linux
medium
low
Target Milestone: ---
Assignee: Tom Coughlan
QA Contact: Brian Brock
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2005-09-16 18:08 UTC by Ashish Tripathi
Modified: 2007-11-30 22:07 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2007-10-19 18:54:12 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)
Result of sysreport (7.69 MB, patch)
2005-09-20 14:49 UTC, Ashish Tripathi
no flags Details | Diff

Description Ashish Tripathi 2005-09-16 18:08:02 UTC
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322)

Description of problem:
Hi,
   I am using Redhat AS 3.0 (2.4.21-20.ELsmp) with EXT3 filesystems. The disks reside on a Fibre connected HP SAN storage. I am using HP Data Protector 5.0 for backups/restores.During backups, the average read speed is around 28 MB/s but during restores the write speeds drops down to 12-14MB/s.I have tried this on RAID 0+1 and RAID 5 storage but resutlts were the same.
    Please help.
Thanks.
Ashish

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


How reproducible:
Always

Steps to Reproduce:
1.Restore to RAID 0+1
2.Restore to RAID5
3.
  

Actual Results:  Results were the same. Write speed was around 12-14 MB/s MB/s.

Expected Results:  Write speed should have been atleast 20-25 MB/s.

Additional info:

Comment 1 Tom Coughlan 2005-09-16 21:59:48 UTC
What is the HBA and driver? what model storage? any error messages in
/var/log/messages?

The easiest way to proivide the needed info is to run sysreport and post the
results. 

To start with, it would be helpful to get some raw I/O performance numbers,
excluding the filesystem, etc. If you have a partition on the storage that you
can scratch, then run a simple test like "badblocks" and compare with "badblocks
-w". Use "vmstat 1" to monitor the performance. Post the reasults. 

Comment 2 Ashish Tripathi 2005-09-19 14:03:29 UTC
Hi, 
   Please find the results of "sysreport" attached. Do I really need to run 
tests on raw device because the issue here is the write performance on the 
same filesystem while read performance is decent. 
Thanks.
Ashish

Comment 3 Ashish Tripathi 2005-09-19 14:05:50 UTC
Please let me know how can I attach the output file of sysreport as it is 
bzipped tar archive and bugzilla site is not allowing to attach it.
Thanks.

Comment 4 Ashish Tripathi 2005-09-20 14:49:18 UTC
Created attachment 119027 [details]
Result of sysreport

I have attached the result of sysreport as requested.
Thanks.

Comment 5 Ernie Petrides 2005-10-04 01:56:12 UTC
Reverting to ASSIGNED state.

Comment 6 RHEL Program Management 2007-10-19 18:54:12 UTC
This bug is filed against RHEL 3, which is in maintenance phase.
During the maintenance phase, only security errata and select mission
critical bug fixes will be released for enterprise products. Since
this bug does not meet that criteria, it is now being closed.
 
For more information of the RHEL errata support policy, please visit:
http://www.redhat.com/security/updates/errata/
 
If you feel this bug is indeed mission critical, please contact your
support representative. You may be asked to provide detailed
information on how this bug is affecting you.


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