LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices


Reply
  Search this Thread
Old 04-24-2017, 12:08 AM   #1
SSy1
LQ Newbie
 
Registered: Apr 2017
Posts: 2

Rep: Reputation: Disabled
RAID1 Monitoring often shows: resync=DELAYED - what does that mean?


I have an automated cron that sends me mdadm status to ensure everything is running fine. Sometimes it looks like this:

Personalities : [raid1]
md2 : active raid1 sda2[0] sdb2[1]
225278912 blocks [2/2] [UU]
[>....................] check = 3.1% (7080320/225278912) finish=23.4min speed=155272K/sec
bitmap: 0/2 pages [0KB], 65536KB chunk

md3 : active raid1 sda3[0] sdb3[1]
242781120 blocks [2/2] [UU]
resync=DELAYED
bitmap: 2/2 pages [8KB], 65536KB chunk

md1 : active raid1 sdb1[1] sda1[0]
261056 blocks [2/2] [UU]
resync=DELAYED

unused devices: <none>

Does that mean that the raid is not synced at that moment? Does the delay relate to the checking process?

Thanks.
 
Old 04-24-2017, 02:59 AM   #2
Guttorm
Senior Member
 
Registered: Dec 2003
Location: Trondheim, Norway
Distribution: Debian and Ubuntu
Posts: 1,374

Rep: Reputation: 403Reputation: 403Reputation: 403Reputation: 403Reputation: 403
Yes. It happens when you have many md devices sharing a single disk, and you are rebuilding them.

What you are seing here is resyncing between sda and sdb. It is a lot faster to resync the md devices after one another, than doing them in parallel. After md2 is finished, you will se it continues with md3 and so on. If it did all at once, the disk heads would have to move a lot - kind of like the difference between random and sequential IO.
 
Old 04-24-2017, 03:52 AM   #3
SSy1
LQ Newbie
 
Registered: Apr 2017
Posts: 2

Original Poster
Rep: Reputation: Disabled
Why is it resyncing however? These are not new drives. What happens if there is a HD crash in the middle of this?
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
weekly once resync is starting itself in RAID1 ananthkadalur Linux - Server 5 08-04-2011 05:50 AM
RAID1 resync very VERY slow using mdadm rontay Linux - Software 7 03-13-2010 10:13 AM
RAID1 resync very VERY slow using mdadm rontay Linux - General 1 03-12-2010 10:19 AM
How do I resync a "dirty" software raid1? isync Linux - Server 2 06-04-2007 01:12 AM
Software RAID1 monitoring Sushy Slackware 1 10-05-2005 08:52 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Software

All times are GMT -5. The time now is 06:21 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration