too many lstat() syscalls, therefore too many IOPS
Andrei Enshin via Any discussion of rdiff-backup <[email protected]>
| Newsgroups | gmane.comp.sysutils.backup.rdiff-backup.general |
|---|---|
| Message-ID | <[email protected]> |
Hi rdiff-backup folks,
Since recent, during backing up I can see spike in IOPS up to 500 which exhaust limit of a VM. Therefore backup process takes very long. I've straced a bit and what I can see is: many failed lstat() syscalls:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
42.71 0.040247 9 4608 1420 lstat
35.41 0.033370 12 2860 getdents
9.41 0.008865 6 1431 open
4.63 0.004363 3 1430 close
4.03 0.003797 3 1431 fstat
3.75 0.003536 2 1417 getuid
0.04 0.000039 39 1 unlink
0.01 0.000013 1 9 read
------ ----------- ----------- --------- --------- ----------------
100.00 0.094230 13187 1420 total
Seems rdiff-backup checks existence of some file/dir:
10:13:16 lstat("/some/path/rdiff-backup-data/increments/foo/bar", 0x7ffd832fa810) = -1 ENOENT (No such file or directory) <0.000020>
After backup is done, there is still no such file.
Seems the part in path - /rdiff-backup-data/increments/ - is some "config" for rdiff-backup and probably it tryies to find something but can't?
What might be wrong in my setup? What would you recommend to check to solve the issue if it is issue at all?
---
Best Regards,
Andrei Enshin