Evren Yurtesen wrote:
> Jason Hughes wrote:
>> That drive should be more than adequate. Mine is a 5400rpm 2mb
>> buffer clunker. Works fine.
>> Are you running anything else on the backup server, besides
>> BackupPC? What OS? What filesystem? How many files total?
>
> FreeBSD, UFS2+softupdates, noatime.
>
> There are 4 hosts that have been backed up, for a total of:
>
> * 16 full backups of total size 72.16GB (prior to pooling and
> compression),
> * 24 incr backups of total size 13.45GB (prior to pooling and
> compression).
>
> # Pool is 17.08GB comprising 760528 files and 4369 directories (as of
> 3/27 05:54),
> # Pool hashing gives 38 repeated files with longest chain 6,
> # Nightly cleanup removed 10725 files of size 0.40GB (around 3/27 05:54),
> # Pool file system was recently at 10% (3/27 07:16), today's max is
> 10% (3/27 01:00) and yesterday's max was 10%.
>
> Host User #Full Full Age (days) Full Size
> (GB) Speed (MB/s) #Incr Incr Age (days) Last
> Backup (days) State Last attempt
> host1 4 5.4 3.88 0.22 6 0.4
> 0.4 idle idle
> host2 4 5.4 2.10 0.06 6 0.4
> 0.4 idle idle
> host3 4 5.4 7.57 0.14 6 0.4
> 0.4 idle idle
> host4 4 5.4 5.56 0.10 6 0.4
> 0.4 idle idle
>
Hmm. This is a tiny backup setup, even smaller than mine. However, it
appears that the average size of your file is only 22KB, which is quite
small. For comparison sake, this is from my own server:
Pool is 172.91GB comprising 217311 files and 4369 directories (as of
3/26 01:08),
The fact that you have tons of little files will probably give
significantly higher overhead when doing file-oriented work, simply
because the inodes must be fetched for each file before seeking to the
file itself. If we assume no files are shared between hosts (very
conservative), and you have an 8ms access time, you will have 190132
files per host and two seeks per file, neglecting actual i/o time, gives
you 50 minutes. Just to seek them all. If you have a high degree of
sharing, it can be up to 4x worse. Realize, the same number of seeks
must be made on the server as well as the client.
Are you sure you need to be backing up everything that you're putting
across the network? Maybe excluding some useless directories, maybe
temp files or logs that haven't been cleaned up? Perhaps you can
archive big chunks of it with a cron job?
I'd start looking for ways to cut down the number of files, because the
overhead of per-file accesses are probably eating you alive. I'm also
no expert on UFS2 or FreeBSD, so it may be worthwhile to research its
behavior with hard links and small files.
JH
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