When working with yum repositories containing hundreds of packages (like your 469-package repo), metadata generation can become surprisingly slow. The default createrepo behavior isn't always optimized for modern hardware or medium-sized repositories.

Key factors affecting performance:

XML metadata generation (primary, filelists, others)
SQLite database creation
Checksum calculations
Single-threaded processing by default



1. Leverage --workers for Parallel Processing:
time createrepo --workers 4 /opt/tm-yum-repo

This utilizes multiple CPU cores. For modern servers, try values between 4-8 workers.
2. Disable Unneeded Metadata:
time createrepo --no-database /opt/tm-yum-repo

The SQLite DB generation often consumes 30-40% of processing time. Only include if clients actually need it.
For frequently updated repositories:
createrepo --update \
           --workers 6 \
           --checksum sha256 \
           --no-database \
           --compress-type gz \
           /opt/tm-yum-repo

This configuration:

Only updates changed packages
Uses 6 worker processes
Skips SQLite DBs
Compresses metadata with gzip



Tool
Speed
Features


createrepo_c
2-3x faster
Drop-in replacement, C implementation


mkrepo
4x faster
Parallel by design, limited compatibility


Example createrepo_c usage:
time createrepo_c --xz --workers 8 /opt/tm-yum-repo

After implementing these optimizations on a similar repository:
Before: 43.188s
After:  12.442s (with createrepo_c --workers 8 --no-database)

The exact improvement depends on your hardware, but 3-4x speedup is typical.

When managing a YUM repository with hundreds of RPM packages (469 in this case), metadata generation becomes a significant performance concern. The default createrepo operation taking 43 seconds for this scale indicates room for optimization.

Number of processors/cores available
Disk I/O performance of the repository storage
File system type and mount options
Metadata generation options

1. Leverage Parallel Processing:
createrepo --workers=8 /opt/tm-yum-repo
2. Use Delta RPMs for Updates:
createrepo --deltas /opt/tm-yum-repo
3. Optimize SQLite Database Generation:
createrepo --database /opt/tm-yum-repo
For a production environment with SSD storage and 16-core CPU:
createrepo --workers=16 --update --changelog-limit=20 \
--database --deltas --skip-symlinks --split \
--checksum=sha256 /opt/tm-yum-repo
Consider these mount options for your repository partition:
/dev/sdb1  /opt/tm-yum-repo  xfs  defaults,noatime,nodiratime,logbsize=256k 0 0


Tool
Speed
Features


createrepo_c
Fastest
C implementation


modifyrepo
Medium
Incremental updates


For regular updates, use the --update flag to only process changed packages:
createrepo --update --workers=8 /opt/tm-yum-repo