Scott Smyth wrote:
>
> Hi;
>
> Now that LVM is in the SGI tree, we would like to
> find out if anybody is seeing similar issues
> around RAID 5 software support and the complaints
> of mount with XFS in the kernel and trying to mount
> LVM volumes:
>
> LVM 0.9 (obviously)
> 2.4.0-test13-pre3 and 2.4.0-prerelease
>
> First, there are two problems we seem to have with
> RAID 5 with LVM on top and XFS as the file system.
> The first is that the MMX optimization in xor.h
> fails and keeps the xor module from even loading
> properly (see attached patch to avoid this). Having
> gotten around that, we then have a problem with
> the rsync daemon. We get a kernel oops (we have not
> had time to use kdb on it yet but will) on the
> starting the raid, but you can still proceed and
> use it. However, it never resyncs nor makes any
> progress to resync according to /proc/mdstat. Then,
> at shutdown of the raidset (or attempted), the
> raid stop hangs. We will give more info as we debug,
> but it is 100% reproduceable.
>
[ ... ]
Hi,
We have seen similar issues both w.r.t the sse optimizations
and w.r.t re-syncing. The sse issue surfaced when the raid
code got re-worked to factor out some of the architecture/processor
specific optimizations. I don't know if accessing the device
while resyncing is intented to work. One workaround for the
resync problem is to wait for the raid to finish resyncing;
the status, as you noted, is reported in /proc/mdstat.
In our test box, the processor is:
----------
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 7
model name : Pentium III (Katmai)
stepping : 2
cpu MHz : 500.141
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 mmx
fxsr sse
bogomips : 996.15
--------------------
I'll cc: Neil Brown who seems to be actively maintaining
the RAID subsystem.
thanks,
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Rajagopal Ananthanarayanan ("ananth")
Member Technical Staff, SGI.
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