[Lustre-discuss] exceedingly slow lstats

[wangdi]

What is your lustre version? It looks like LU-15.

Thanks
WangDi
On 01/20/2012 02:35 PM, John White wrote:
> Well, I was reading the strace wrong anyway:
> lstat("../403/a323", {st_mode=S_IFREG|0644, st_size=0, ...}) = 0<0.134326>
> getxattr("../403/a323", "system.posix_acl_access", 0x0, 0) = -1 EOPNOTSUPP (Operation not supported)<0.000018>
> lstat("../403/a330", {st_mode=S_IFREG|0644, st_size=0, ...}) = 0<0.158898>
> getxattr("../403/a330", "system.posix_acl_access", 0x0, 0) = -1 EOPNOTSUPP (Operation not supported)<0.000019>
> lstat("../403/a331", {st_mode=S_IFREG|0644, st_size=0, ...}) = 0<0.239466>
> getxattr("../403/a331", "system.posix_acl_access", 0x0, 0) = -1 EOPNOTSUPP (Operation not supported)<0.000012>
> lstat("../403/a332", {st_mode=S_IFREG|0644, st_size=0, ...}) = 0<0.130146>
> getxattr("../403/a332", "system.posix_acl_access", 0x0, 0) = -1 EOPNOTSUPP (Operation not supported)<0.000012>
>
> The getxattr takes an incredibly short amount of time, it's the lstat itself that's taking 0.1+s.
> ----------------
> John White
> HPC Systems Engineer
> (510) 486-7307
> One Cyclotron Rd, MS: 50C-3396
> Lawrence Berkeley National Lab
> Berkeley, CA 94720
>
> On Jan 20, 2012, at 2:28 PM, Mark Hahn wrote:
>
>>> I'm sorry, I'm not quite understanding what you're asking.  I don't have
>>> ACLs specifically enabled anywhere (and would expect the default is
>>> disabled).
>> I guess what I was suggesting is that you could try a simple experiment:
>> mount a client requesting the acl mount option.  (I don't know whether the "mount -oremount,acl ..." trick will work with Lustre.)
>>
>> if the problem goes away, you're done.
>>
>> you also mentioned OSS load - I don't see how that could be related,
>> since OSSs are not involved in metadata operations like lstat or getxattr.
>> (though depending on Lustre version, they could be involved in fetching
>> actual size of files, which is especially salient on striped files...)
>>
>>
>>
>>> ----------------
>>> John White
>>> HPC Systems Engineer
>>> (510) 486-7307
>>> One Cyclotron Rd, MS: 50C-3396
>>> Lawrence Berkeley National Lab
>>> Berkeley, CA 94720
>>>
>>> On Jan 20, 2012, at 12:49 PM, Mark Hahn wrote:
>>>
>>>>>    0.916908 getxattr("/global/scratch/jwhite/backuptest/highcount/3/a5", "system.posix_acl_access", 0x0, 0) = -1 EOPNOTSUPP (Operation not supported)
>>>> are your clients mounting with the acl option
>>>> and acl isn't missing on the mds mount?
>> -- 
>> operator may differ from spokesperson.	            hahn at mcmaster.ca
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