robobub Posted July 15, 2020 Share Posted July 15, 2020 I noticed my cache read speeds were quite slow and did some investigation. I had recently switched from btrfs-encrypted cache to xfs-encrypted cache due. It seems that on my system my read speeds with xfs/reiserfs encrypted cache are extremely slow, while unencrypted or btrfs-encrypted is much faster. Any ideas what could be going on? Anyone else have this issue? reiserfs-encrypted 130 MB/s write 25 MB/s read xfs-encrypted 130 MB/s write 20 MB/s read xfs-unencrypted 200 MB/s write 450 MB/s read btrfs-encrypted 130 MB/s write 450 MB/s read Methodology: # urandom to ensure it's not due to the SSD controller compressing the data dd if=/dev/urandom of=/mnt/cache/test bs=4M count=256 conv=fsync # remove from cache before reading sync; echo 3 > /proc/sys/vm/drop_caches dd of=/dev/null if=/mnt/cache/test bs=4M count=256 Also verified speeds with dstat -D sdb. Writing/reading to array itself is as expected, ~80 MB/s for both read and write. SSD Cache drive: ATA SAMSUNG SSD 830 (scsi) CPU: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz Unraid: 6.8.3 changes to blockdev readahead, io scheduler, nr_requests all have no effect and are set to default and rebooted. All dockers/vm/scripts off. All shares set to not use cache. Quote Link to comment
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