Materialized backups using extra disk space

[ke...@indeed.com]

With several of our backups, as incrementals are applied, the materialized version uses a lot more disk space than it should:

$ sudo du -ma dbname

16540   dbname/table1.ibd

8588    dbname/table2.ibd

4948    dbname/table3.ibd

$ sudo du --apparent-size -ma dbname

8400    dbname/table1.ibd

4504    dbname/table2.ibd

2904    dbname/table3.ibd

The table1.ibd.delta files are less than 20 MB each, but after 7 incrementals, the disk usage of table1.idb has grown from 8349 MB to a whopping 16540 MB (but ls shows the expected 8808038400 bytes).

I think all of the bloated tables use TEXT, BLOB, or ROW_FORMAT=COMPRESSED.  Is this a known issue?

I see it with Percona Server 5.5.25a - 5.5.28 and the current percona-xtrabackup 2.0.4.

Thanks!

[Dave Hicks]

Probably better to ask on the Percona Xtrabackup forum. That would be
an issue with Xtrabackup itself, not the backup manager.

[ke...@indeed.com]

I can open a Percona support ticket, but since xbm materializes by default, I thought an xbm user may have already dealt with this.