How to disable data persistence on disk?

89 views
Skip to first unread message

Bruno Costa

unread,
May 4, 2016, 1:22:06 PM5/4/16
to Alluxio Users

Hi guys,

Seems that by default Alluxio persists data in /mnt/ramdisk/alluxioworker. I just want my data in RAM memory, only in memory. How can I disable such persistence remaining the data only in RAM?

Thanks!


Regards,

Andrew Audibert

unread,
May 4, 2016, 1:35:48 PM5/4/16
to Bruno Costa, Alluxio Users
Hi Bruno,

Ramdisk is RAM memory which acts like disk, so anything stored inside a ramdisk directory already exists only in RAM memory. The contents of /mnt/ramdisk are not persistent.

Hope that helps,
Andrew

--
You received this message because you are subscribed to the Google Groups "Alluxio Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to alluxio-user...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Bruno Costa

unread,
May 4, 2016, 2:12:05 PM5/4/16
to Alluxio Users, brunoco...@gmail.com
Thanks Andrew,

So, by default, Alluxio doesn't persist data in disk, right? 

My question is because I`m conducting some tests with two scenarios: Spark/HDFS and SPARK/Alluxio/HDFS. In the former the time is quite bigger than by using Alluxio... it's about 5 minutes to load 3GB data to Alluxio, while 2 minutes with Spark/HDFS.

Gene Pang

unread,
May 14, 2016, 2:01:32 AM5/14/16
to Alluxio Users, brunoco...@gmail.com
Hi,

Could you describe your setup with more details? What workload are you running on Spark? What does the data look like? Are Spark nodes co-located with Alluxio workers?

Thanks,
Gene

Chanh Le

unread,
Aug 10, 2016, 3:37:52 AM8/10/16
to Alluxio Users

Hi Gene,
When I stop worker in a node it doesn't delete the data in /mnt/ramdisk/.

du -s -h /mnt/ramdisk/data/alluxioworker/
19G     /mnt/ramdisk/data/alluxioworker/

Even I checked there is a process in ramdisk or not but it didn't.

lsof /mnt/ramdisk
Empty

I can not free my RAM by 
sync; echo 3 > /proc/sys/vm/drop_caches

But When I deleted the folder in /mnt/ramdisk/data/
It's OK, I attached the image to prove that.

Gene Pang

unread,
Aug 10, 2016, 9:07:58 AM8/10/16
to Alluxio Users
The ramdisk folder will not be deleted unless you format the worker, or if you restart the machine.

Hope that helps,
Gene

Gene Pang

unread,
Aug 19, 2016, 9:19:47 AM8/19/16
to Alluxio Users
Hi Chanh,

Were we able to answer your questions?

Thanks,
Gene

Chanh Le

unread,
Aug 19, 2016, 9:29:39 AM8/19/16
to Gene Pang, Alluxio Users
Hi Gene,
For me I have been this before the way to do that is just don’t setup the underFs like HDFS or S3.
I think it safe if you don’t setup a cluster (multi nodes) just run in 1 node because in cluster mode Alluxio need underFs to exchange block between node.


Regards,
Chanh




--
You received this message because you are subscribed to a topic in the Google Groups "Alluxio Users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/alluxio-users/bg5JZE40g1M/unsubscribe.
To unsubscribe from this group and all its topics, send an email to alluxio-user...@googlegroups.com.

Chanh Le

unread,
Aug 19, 2016, 9:31:54 AM8/19/16
to Gene Pang, Alluxio Users
Hi Gene,
Sorry for mis understand the question.
Yes I solved it by delete the folder /mnt/ramdisk/data/alluxioworker/


Regards,
Chanh

Gene Pang

unread,
Aug 19, 2016, 9:32:35 AM8/19/16
to Alluxio Users
Ok, sounds good. Thanks for confirming!

-Gene
Reply all
Reply to author
Forward
0 new messages