[Moosefs-users] MFS Access very slow during chunk deletions

[Ólafur Ó. <osv...@ne...>]

Hi,
Our system had just over 4.5 million chunks untill one week ago when a good deal of the data was deleted (on purpose).

Today the trash time expired and it seems that our master is deleting all the unused chunks which is quite normal except each server of 10 is doing up to 5.5k chunk deletions pr. minute and all systems accessing the MFS partitions are very slow and that started at the same time as the chunk deletions.

Is there any way to tune MFS so that chunk deletions don't have such an impact on the system, can we somehow control how many chunks are deleted at once in max rate pr. minute or maybe have it somehow linked to chunkserver/master load?

The network links are not saturated and none of the servers seem to be loaded at all?

The disk io on the master even went down when this started, as did the CPU usage of the server, but the memory usage has gone up about 30%

Could it be that the master process is not handling all this at once?

/Oli

--
Ólafur Osvaldsson
System Administrator
Nethonnun ehf.
e-mail: osv...@ne...
phone: +354 517 3400