-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 08/02/11 16:00, taemun wrote: > It's generally accepted that two things can break a ZFS pool: the use of > non-ECC RAM; and storage devices which do not respect cache flushes. You're > aiming for a system which is likely to have both. The latter by virtue of > the fact that most USB <=> SATA controllers often don't respect sync > requests. Both of these can lead to broken metadata/uberblocks and hence a > broken pool.
Caché flushes are important. The fist step I do when getting a new computer&disk is to write a small program (like 5 lines long) to write small (1 byte) data followed by a "fsync". If the number of fsyncs per second is too high, I know I can't trust the disk. Python code: """ import os, time syncs = 10000 f = open("zz","w") t = time.time() for i in xrange(syncs) : f.write("a") f.flush() os.fsync(f) print "Realizamos %d transacciones por segundo" %(syncs/(time.time()-t)) """ Using 7200 RPM disks, the right value is around 120 transactions per second. If the value is far higher, "somebody" is lying to you about caché flushes. - -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ j...@jcea.es - http://www.jcea.es/ _/_/ _/_/ _/_/ _/_/ _/_/ jabber / xmpp:j...@jabber.org _/_/ _/_/ _/_/_/_/_/ . _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQCVAwUBTVFgJplgi5GaxT1NAQIVWQP6AonuiAf53+CbD/5h9Y1eDY3bMGLCCjDO 850c13/UBoClAIjda20Z8P2JW1PgVuf7ExN4uW9AdhEN/fKYEd7wZv/XPINyPktK Tp0Q1TYp+sXBY5uQnFi3br3iy3OP/AgsYDwYtN59MOj67WE/HftQRavOkccPGXC0 YdOJhfjvLB0= =IoZv -----END PGP SIGNATURE----- _______________________________________________ OpenIndiana-discuss mailing list OpenIndiana-discuss@openindiana.org http://openindiana.org/mailman/listinfo/openindiana-discuss