We have DELL server with MD1000 Disk array in it. O.S. is CENTOS 5.5. Recently every time MD1000 "patrol read" start I will get "media error" messages on /var/log/message file.
I use MD1000 "slow initialize" to initialize "bad disk" and NO error. After "slow initialize" finish, I manually "startup patrol read". I continue get "media error" on /var/log/message.
Anyone know what difference between "slow initialize" and "patrol read"?
Thanks.
mcclnx mcc wrote:
We have DELL server with MD1000 Disk array in it. O.S. is CENTOS 5.5. Recently every time MD1000 "patrol read" start I will get "media error" messages on /var/log/message file.
I use MD1000 "slow initialize" to initialize "bad disk" and NO error. After "slow initialize" finish, I manually "startup patrol read". I continue get "media error" on /var/log/message.
Anyone know what difference between "slow initialize" and "patrol read"?
No, but let me suggest to you that "media error" means just that, a bad drive.
mark
Thank you for answer. I know "media error" mean disk going to bad. I want to know why "slow initialize" did NOT complain bad block. Based on DELL document "slow initialize" will check bad block.
--- 11/6/8 (三)，m.roth@5-cent.us m.roth@5-cent.us 寫道：
寄件者: m.roth@5-cent.us m.roth@5-cent.us 主旨: Re: [CentOS] what is difference between "slow initialize" and "patrol read" on RAID? 收件者: "CentOS mailing list" centos@centos.org 日期: 2011年6月8日,三,下午3:11 mcclnx mcc wrote:
We have DELL server with MD1000 Disk array in
it. O.S. is CENTOS 5.5.
Recently every time MD1000 "patrol read" start I will
get "media error"
messages on /var/log/message file.
I use MD1000 "slow initialize" to initialize "bad
disk" and NO error.
After "slow initialize" finish, I manually "startup
patrol read". I
continue get "media error" on /var/log/message.
Anyone know what difference between "slow initialize"
and "patrol read"?
No, but let me suggest to you that "media error" means just that, a bad drive.
mark
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Wednesday, June 08, 2011 09:00:48 PM mcclnx mcc wrote:
We have DELL server with MD1000 Disk array in it. O.S. is CENTOS 5.5. Recently every time MD1000 "patrol read" start I will get "media error" messages on /var/log/message file.
I use MD1000 "slow initialize" to initialize "bad disk" and NO error. After "slow initialize" finish, I manually "startup patrol read". I continue get "media error" on /var/log/message.
Anyone know what difference between "slow initialize" and "patrol read"?
Only Dell really knows what they mean by it.
But here are some random thoughts:
* Slow init may write all of the disk during init but maybe: 1) no errors happen during write 2) it notices an error but retries silently 3) it notices an error but has sucky error reporting * Patrolread (may) compare parity data and report this as "media error" (a type of error slow init probably wouldn't detect) * The I/O pattern of patrolread compared to slow init provoks an error
You could try to take this issue over to the poweredge-linux mailing list or just case the bad drive with dell support.
/Peter
On Wednesday, June 08, 2011 09:00:48 PM mcclnx mcc wrote:
We have DELL server with MD1000 Disk array in it. O.S. is CENTOS 5.5. Recently every time MD1000 "patrol read" start I will get "media error" messages on /var/log/message file.
I use MD1000 "slow initialize" to initialize "bad disk" and NO error. After "slow initialize" finish, I manually "startup patrol read". I continue get "media error" on /var/log/message.
Anyone know what difference between "slow initialize" and "patrol read"?
Only Dell really knows what they mean by it.
But here are some random thoughts:
- Slow init may write all of the disk during init but maybe:
- no errors happen during write
- it notices an error but retries silently
- it notices an error but has sucky error reporting
Yes, both can be true. I guess it's simply because a disk which writes on a bad sector/block just silently remaps it and goes on because it's considered fixed.
- Patrolread (may) compare parity data and report this as "media error" (a type of error slow init probably wouldn't detect)
- The I/O pattern of patrolread compared to slow init provoks an error
I always tought patrolread just tries to read the whole disk to detect sleeping bad sectors/blocks. Maybe it also checks consistency on the RAID level but I'm not sure.
Simon
For your reference:
http://stuff.mit.edu/afs/athena/dept/cron/documentation/dell-server-admin/en...
Hopefully that answers the question.
-
Geoff Galitz -
m.roth＠5-cent.us -
mcclnx mcc -
Peter Kjellström -
Simon Matter