@Chris, thanks, i did some tests and now we have some numbers. tl;rd the results is pretty
satisfying me, even if there no speedup in my case, but there is a lot disk space could be
saved and reduce writes. Probably not worth file a bug, but a little bit weird that with
zstd:1 still a little bit slower on HDD and on SSD speed equal.
---
! Note: please use monospace font to save formatting.
CPU: Quad Core AMD Athlon X4 845
Kernel: 5.7.11-200.fc32.x86_64 (non-debug)
btrfs-progs: 5.7-4
Scheduler: mq-deadline
Mount options:
- HDD: rw,relatime,seclabel,space_cache=v2,autodefrag
- SSD: rw,relatime,seclabel,compress=lzo,ssd,space_cache=v2
To produce more precise results do some things before:
- Disable ZRAM:
sudo systemctl stop zram-swap.service
- Download all necessary packages before build to exclude time required for downloading
package from internet. After that you can run mock with '--offline' option.
- Before every benchmark clean-up mock:
mock --isolation=simple clean -r fedora-32-x86_64
## How to reproduce?
1. git clone
https://src.fedoraproject.org/rpms/gnome-flashback.git
2. cd gnome-flashback/
3. spectool -g gnome-flashback.spec
4. mock --isolation=simple -r fedora-32-(uname -m) --rebuild --sources . --spec
gnome-flashback.spec --offline
## Results (HDD)
### Compression: lzo
Took: 6m53s
Processed 42492 files, 24340 regular extents (26282 refs), 24114 inline.
Type Perc Disk Usage Uncompressed Referenced
TOTAL 63% 992M 1.5G 1.7G
none 100% 389M 389M 442M
lzo 50% 603M 1.1G 1.3G
### Compression: zstd:1
Took: 7m5s
Processed 42492 files, 24232 regular extents (26219 refs), 24861 inline.
Type Perc Disk Usage Uncompressed Referenced
TOTAL 46% 738M 1.5G 1.7G
none 100% 280M 280M 317M
zstd 35% 458M 1.2G 1.4G
### Compression: zstd:3
Took: 7m8s
Processed 42492 files, 24104 regular extents (26059 refs), 24940 inline.
Type Perc Disk Usage Uncompressed Referenced
TOTAL 45% 707M 1.5G 1.7G
none 100% 270M 270M 306M
zstd 33% 437M 1.2G 1.4G
### Compression: none
Took: 7m18s
## Various combinations with aditional tweaks:
### Compression: zstd:1
Addtional mount options: noautodefrag
Took: 7m3s
### Compression: zstd:1
Addtional mount options: noatime
Took: 7m1s
---
## Results (SSD)
### Compression: lzo
Took: 2m26s
### Compression: zstd:1
Took: 2m26s
### Compression: zstd:3
Took: 2m28s
### Compression: zstd:14
Took: 4m9s
Processed 42495 files, 25883 regular extents (27868 refs), 25013 inline.
Type Perc Disk Usage Uncompressed Referenced
TOTAL 42% 673M 1.5G 1.7G
none 100% 272M 272M 310M
zstd 30% 401M 1.2G 1.4G
### Compression: none
Took: 2m24s