[Ocfs2-users] ENOSPC

[Sunil Mushran]

Please file a bugzilla. This may involve more people. And it
is easier to track that way.

David Johle wrote:
> See attachment for requested output.
>
> At 08:54 PM 3/24/2010, Sunil Mushran wrote:
>> Quite a bit of work is ongoing on this front. I'll list all that work
>> in another email.
>>
>> Meanwhile make a bz with the stat_sysdir output. We'll need that
>> to determine the best way forward.
>>
>> David Johle wrote:
>>> So in light of prior issues with lock contention and such due to 
>>> writing apache logs to shared files I have started storing them 
>>> locally on each node.  I made a script to combine them nightly 
>>> before the statistics generator kicks off for the previous day's 
>>> traffic analysis.
>>>
>>> This script, using logresolvemerge.pl, is actually writing the 
>>> output back to the shard volume for easy reference later.  I figure 
>>> I would not have issues with this as it's a large amount of 
>>> sequential writes from a single node at off-peak time.  However, 
>>> It's been getting hung with high CPU from the merger.
>>>
>>> I'm pretty sure I'm running into the famous "free space 
>>> fragmentation" problem, but wanted to confirm that this was the case 
>>> or see if there was additional troubleshooting I can do.
>>>
>>> Here's the disk, plenty of overall free space:
>>>
>>> Filesystem           1K-blocks      Used Available Use% Mounted on
>>> /dev/mapper/mpath1   209725440  85311460 124413980  41% 
>>> /san/live-websites
>>>
>>>
>>> While my merging was going 100% of a CPU core, but the merged file 
>>> was not growing in size and not much I/O actually happening to the 
>>> shared volume, I did an strace to see what it was doing and got this:
>>>
>>> # strace -p 16844
>>> Process 16844 attached - interrupt to quit
>>> read(3, "1\" 200 936 \"http://www.industria"..., 4096) = 4096
>>> write(1, ".NET CLR 1.1.4322; .NET CLR 2.0."..., 4096) = -1 ENOSPC 
>>> (No space left on device)
>>> read(4, "oration&locationName=South+Jerse"..., 4096) = 4096
>>> write(1, "ivers=8&ngPipelines=600&kvtl230="..., 4096) = -1 ENOSPC 
>>> (No space left on device)
>>> read(4, "1\" 200 936 \"http://www.industria"..., 4096) = 4096
>>> write(1, "gan+Boulevard&locationCSZ=Salem%"..., 4096) = -1 ENOSPC 
>>> (No space left on device)
>>> read(3, "HTTP/1.0\" 200 4096 \"-\" \"WinampMP"..., 4096) = 4096
>>> write(1, "elta=.375&zoomlevel=6&label=Sout"..., 4096) = -1 ENOSPC 
>>> (No space left on device)
>>> read(4, "HTTP/1.0\" 200 4096 \"-\" \"WinampMP"..., 4096) = 4096
>>> write(1, "ident/4.0; .NET CLR 1.1.4322; .N"..., 4096) = -1 ENOSPC 
>>> (No space left on device)
>>> read(3, "0 36516 \"-\" \"Mozilla/5.0 (compat"..., 4096) = 4096
>>>
>>>
>>> Now I'm really worried about the cluster stability from other 
>>> routine writes that might fail soon.  I know the typical workaround 
>>> is to reduce the node slots, but I don't have any excess slots to 
>>> spare.  Are there any other tricks to improve/reduce freespace 
>>> fragmentation?