Bug 139039 - [zfs] zpool scrub makes system unbearably slow
Summary: [zfs] zpool scrub makes system unbearably slow
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 9.0-CURRENT
Hardware: Any Any
: Normal Affects Only Me
Assignee: Pawel Jakub Dawidek
Depends on:
Reported: 2009-09-21 23:30 UTC by Nathaniel Filardo
Modified: 2018-05-28 19:42 UTC (History)
0 users

See Also:


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Description Nathaniel Filardo 2009-09-21 23:30:03 UTC
Even with the sysctl "vfs.zfs.scrub_limit" given value 2, scrubbing my 8-disk array is an exercise in frustration.  The system remains online, and will eventually respond to events, but it's incredibly lagged, even when the events do not directly relate to the controller card and disks making up the array.

The array is 4x320G and 4x750G SATA disks on a
mpt0: <LSILogic SAS/SATA Adapter> port 0x300-0x3ff mem 0x100000-0x103fff,0x130000-0x13ffff at device 1.0 on pci3
mpt0: MPI Version=

For (I assume unrelated) stability reasons (see pr kern/117688), I have had to run "camcontrol tags $DISK -N 16" for each of the disks in the array.

WITNESS and INVARIANTS are both turned on; I've not tried with them off; should I?

How-To-Repeat: Reliably triggered by issuing a scrub request.
Comment 1 Mark Linimon freebsd_committer freebsd_triage 2009-09-22 05:16:07 UTC
Responsible Changed
From-To: freebsd-bugs->freebsd-fs

Over to maintainer(s).
Comment 2 Pawel Jakub Dawidek freebsd_committer 2014-06-01 07:09:34 UTC
State Changed
From-To: open->feedback

Could you tell which threads are consuming most CPU time? 
Pasting first few lines from 'top -SH' should be enough. 

Comment 3 Pawel Jakub Dawidek freebsd_committer 2014-06-01 07:09:34 UTC
Responsible Changed
From-To: freebsd-fs->pjd

I'll take this one.
Comment 4 Pawel Jakub Dawidek freebsd_committer 2014-06-01 07:09:34 UTC
State Changed
From-To: feedback->suspended

I cannot reproduce the problem on my test machine, it can be related to 
the mpt(4) driver and not ZFS, hard to say. Suspend PR for now.
Comment 5 Eitan Adler freebsd_committer freebsd_triage 2018-05-28 19:42:15 UTC
batch change:

For bugs that match the following
-  Status Is In progress 
- Untouched since 2018-01-01.
- Affects Base System OR Documentation


Reset to open status.

I did a quick pass but if you are getting this email it might be worthwhile to double check to see if this bug ought to be closed.