On 20.09.2017 at 16:56 wrote 'Yannic' via bareos-users: > So I continued testing and increased the file history size because the data I > am trying to back up consists of more than 10000000 (default) > files/directories. So far so good. > > I only need some verification on one topic which is related to the directive > above. > > When using this directive the Bareos documentation points out: > > "Please note! This uses a large memory mapped file (File History Size ∗256=⇒ > around 2,3 GB for the File History Size = 10000000). On 32-bit systems or if > a memory limit for the user running the Bareos Director (normally bareos) > exists (verify by su - bareos -s /bin/sh -c "ulimit -a"), this may fail. > Version >= 15.2.4" > > I also assume that the file which is created during the backup is mapped to > physical memory. > > So if I understand this correctly I would need around 7GB of RAM for a backup > job which consists of 30000000 files/directories ( (256*30000000)/(1024^3) ). > And with 7 jobs backing up the same amount of files/directories I would need > 7 times the amount of RAM (around 50GB). > > As far as I can tell this matches what I see in the monitoring during my > testing. > > So if I am right (?) the only option to use less RAM would be to backup less > files/directories per job. > > Please correct me if I am wrong. > I would be glad if someone can enlighten me.
AFAIK, a memory mapped file can be much larger than your physical memory, however, it can not be larger than the maximum memory your processor can address. So I doubt, that you will need this much memory. Also, if your NDMP storage supports HIST = F in principle, Bareos did not require this temporary database at all. However, I'm not sure, if this is already implemented. F: Specifies path-based file history. This is the most efficient with Bareos. regards, Jörg -- Jörg Steffens [email protected] Bareos GmbH & Co. KG Phone: +49 221 630693-91 http://www.bareos.com Fax: +49 221 630693-10 Sitz der Gesellschaft: Köln | Amtsgericht Köln: HRA 29646 Komplementär: Bareos Verwaltungs-GmbH Geschäftsführer: S. Dühr, M. Außendorf, Jörg Steffens, P. Storz -- You received this message because you are subscribed to the Google Groups "bareos-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. For more options, visit https://groups.google.com/d/optout.
