On 06/27/2011 11:59 AM, Jim Klimov wrote: > >> I'd like to ask about whether there is a method to enforce a >> certain txg >> commit frequency on ZFS. > > Well, there is a timer frequency based on TXG age (i.e 5 sec > by default now), in /etc/system like this: > > set zfs:zfs_txg_synctime = 5
When trying to read the value through mdb I get: # echo zfs_txg_synctime::print | mdb -k mdb: failed to dereference symbol: unknown symbol name Is this some new addition in S11E? > Also there is a buffer-size limit, like this (384Mb): > set zfs:zfs_write_limit_override = 0x18000000 > > or on command-line like this: > # echo zfs_write_limit_override/W0t402653184 | mdb -kw Currently my value for this is 0. How should I set it? I'm writing ~15MB/s and would like txg flushes to occur at most once every 10 seconds. Should I set it to 150MB then? > We had similar spikes with big writes to a Thumper with SXCE in the pre-90's > builds, when the system would stall for seconds while flushing a 30-second TXG > full of data. Adding a reasonable megabyte limit solved the unresponsiveness > problem for us, by making these flush-writes rather small and quick. I need to do the opposite - I don't need to shorten the interval of writes, I need to increase it. Can I do that using zfs_write_limit_override? Thanks. -- Saso _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
