-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Thierry Florac wrote: > Le mercredi 16 juillet 2008 à 21:22 -0400, Tres Seaver a écrit : >>> Application setup includes a ZEO server managing two databases (a "main" >>> one for common data and a "catalog" to store catalog), and two Zope >>> clients (one as main frontend and another one for uncommon >>> administration tasks, both with standard threads count of 4). >>> Database sizes (when packed) are of 280 and 400 MB ; Zope clients caches >>> are of 300 and 500 MB, for 40000 and 80000 objects. >>> >>> All data are stored on two mirrored (via RAID 1) Hitachi SAN with quite >>> good writing speed. >> Because you need fast *seek* speed, too, I would recommend trying your >> app with the ZODB on local disk, first. In fact, I never recommend >> putting the main ZODB on a non-local disk, for just this reason. The >> usage pattern of FileStorage (one big file, writing only at the end, but >> with lots of random-access reads throughout) is nearly worst-case for >> such deployments. >> >> I have one client whose setup is similar (Linux, but using a "big iron" >> SAN), where the first phase of incremental repozo backup (the part >> checking whether incremental is possible) takes longer by a factor of >> two than just doing a full backup. Putting it on local disk both makes >> writes go faster and makes incremental backup feasible. > > Actually, I've already seen that "big reads/writes" are efficient on the > SAN (more than 40 MB/s) but small ones (many 'seek' and 'read' of 8 Ko > as made by ZEO) are not efficient at all ; I'll try to see if putting > ZEO databases as well as Zope clients caches on local disks (which are > also mirrored) can be more efficient (a hourly cron job can then copy > ZEO databases on the SAN for data security, I think...).
Rather than copying the open file, which can potentially lose a transaction which occurs during the copy, I would use the 'repozo' script to create backup sets onto the remote drive. Tres. - -- =================================================================== Tres Seaver +1 540-429-0999 [EMAIL PROTECTED] Palladion Software "Excellence by Design" http://palladion.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFIf0tO+gerLs4ltQ4RAgCQAJsFH019JfoVpqrsMCI0FGHE6aG7iwCeIMi7 rYIjpPBQ36tP3YTk8Yr3B+c= =CXZK -----END PGP SIGNATURE----- _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev