Which one to choose ext4 vs XFS for disk format

raulk89

Hi

From vertica 11 onwards, I see that XFS is also supported on RHEL8.

With previous vertica versions I had ext4 format.

What do you think which of these is best suited for vertica..?

Regards
Raul

mosheg

Because of the relation between the infrastructure CPU, I/O workload and File System behaver I would recommend to measure the performance on the target server and storage system to make sure you choose the appropriate type of file system.
In performance tests about 2 years ago the only measurement that showed more than a 2% difference in performance between the Ext4 and XFS filesystems showed that XFS was a bit slower when adding nodes.
In general Ext4 file system tend to perform better on systems that have limited I/O capability.
For systems with higher capability, XFS tends to be sometimes a bit faster.
Note that XFS consumes about twice the CPU-per-metadata operation compared to Ext4, so if you have a CPU-bound workload with little concurrency, then Ext4 will be faster.
About volume size, Ext4 max file system size on RHEL 6 was 16TB, but now on RHEL 7 and 8 it is 50TB
While the maximum supported XFS file system image is 500TB for RHEL 7 and 1PB for 8.

raulk89

Thanks.
Also, with XFS there may arise this fragmentation issue as well.

Ext4 seems reasonable enough for me.

Regards
Raul