* A puzzling thing about RAID5: syslogd write the log success but another process can not read the /var/log/messages
@ 2004-04-07 13:24 Gewj
2004-04-07 14:51 ` Lars Marowsky-Bree
0 siblings, 1 reply; 4+ messages in thread
From: Gewj @ 2004-04-07 13:24 UTC (permalink / raw)
To: linux-kernel
hammm,tonight is funny because I got a puzzling thing just as....
my setup is a two-scsi-disk raid5 configuration...
(Linux version 2.4.18-18.7.xsmp (Red Hat Linux 7.3 2.96-112)) #1 SMP Wed
Nov 13 19:01:42 EST 2002)
it work well for a long time, but now I found some day early one of the
scsi disks failed, and I found out
that that time syslogd restarted(why??) and it could write log infor to
log file successfully.
but at the same time , another process(named such as B,run by root) can
not read
the /var/log/messages,or what's more exactly, the messages file was look
like empty to B then.
(of course, the syslogd write log infor to /var/log/messages )
I wonder that if syslogd write the log infor to the well-work scsi disk
, but the process B
read the /var/log/messages from the crashed scsi disk,which cause it
just like a empty file.
yes, it is quite unbelievable. but can some one show me a clue to this
puzzling problem?
What is the proper course of this action?
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: A puzzling thing about RAID5: syslogd write the log success but another process can not read the /var/log/messages
2004-04-07 13:24 A puzzling thing about RAID5: syslogd write the log success but another process can not read the /var/log/messages Gewj
@ 2004-04-07 14:51 ` Lars Marowsky-Bree
2004-04-07 23:13 ` Neil Brown
0 siblings, 1 reply; 4+ messages in thread
From: Lars Marowsky-Bree @ 2004-04-07 14:51 UTC (permalink / raw)
To: Gewj, linux-kernel
On 2004-04-07T21:24:01,
Gewj <geweijin@sinosoft.com.cn> said:
> hammm,tonight is funny because I got a puzzling thing just as....
>
> my setup is a two-scsi-disk raid5 configuration...
Impossible. RAID5 requires at least three disks.
Sincerely,
Lars Marowsky-Brée <lmb@suse.de>
--
High Availability & Clustering \ ever tried. ever failed. no matter.
SUSE Labs | try again. fail again. fail better.
Research & Development, SUSE LINUX AG \ -- Samuel Beckett
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: A puzzling thing about RAID5: syslogd write the log success but another process can not read the /var/log/messages
2004-04-07 14:51 ` Lars Marowsky-Bree
@ 2004-04-07 23:13 ` Neil Brown
2004-04-09 1:49 ` Gewj
0 siblings, 1 reply; 4+ messages in thread
From: Neil Brown @ 2004-04-07 23:13 UTC (permalink / raw)
To: Lars Marowsky-Bree; +Cc: Gewj, linux-kernel
On Wednesday April 7, lmb@suse.de wrote:
> On 2004-04-07T21:24:01,
> Gewj <geweijin@sinosoft.com.cn> said:
>
> > hammm,tonight is funny because I got a puzzling thing just as....
> >
> > my setup is a two-scsi-disk raid5 configuration...
>
> Impossible. RAID5 requires at least three disks.
Wrong. RAID5 works fine with just two drives. Try it.
NeilBrown
(I admit that there isn't a lot of point doing raid5 with two drives
as raid1 should provide identical functionality with better
performance, but it makes an interesting base-line for performances
tests on N-drive arrays).
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: A puzzling thing about RAID5: syslogd write the log success but another process can not read the /var/log/messages
2004-04-07 23:13 ` Neil Brown
@ 2004-04-09 1:49 ` Gewj
0 siblings, 0 replies; 4+ messages in thread
From: Gewj @ 2004-04-09 1:49 UTC (permalink / raw)
To: Neil Brown; +Cc: Lars Marowsky-Bree, linux-kernel
thank for your comments
I should say that this question maybe end up without any reasonable result,
the system is now work well , I have give up investigating this problem
any more.
maybe the question is just cause by the RAID card crash.
Neil Brown wrote:
>On Wednesday April 7, lmb@suse.de wrote:
>
>
>>On 2004-04-07T21:24:01,
>> Gewj <geweijin@sinosoft.com.cn> said:
>>
>>
>>
>>>hammm,tonight is funny because I got a puzzling thing just as....
>>>
>>>my setup is a two-scsi-disk raid5 configuration...
>>>
>>>
>>Impossible. RAID5 requires at least three disks.
>>
>>
>
>Wrong. RAID5 works fine with just two drives. Try it.
>
>NeilBrown
>
>(I admit that there isn't a lot of point doing raid5 with two drives
>as raid1 should provide identical functionality with better
>performance, but it makes an interesting base-line for performances
>tests on N-drive arrays).
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html
>Please read the FAQ at http://www.tux.org/lkml/
>
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2004-04-09 1:49 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-04-07 13:24 A puzzling thing about RAID5: syslogd write the log success but another process can not read the /var/log/messages Gewj
2004-04-07 14:51 ` Lars Marowsky-Bree
2004-04-07 23:13 ` Neil Brown
2004-04-09 1:49 ` Gewj
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).