Date: Wed, 4 Jan 2017 10:43:09 -0800 From: Xin LI <delphij@gmail.com> To: Freddie Cash <fjwcash@gmail.com> Cc: FreeBSD Filesystems <freebsd-fs@freebsd.org> Subject: Re: Check status of background destroy Message-ID: <CAGMYy3uU6bUfjufXFQXbNT2krnRnOj-YC2069ep_2tNjDJuw4A@mail.gmail.com> In-Reply-To: <CAOjFWZ4S42mebL15iT8=TLcfvabBWeUdLDzi_d3WfhKTpuGdOw@mail.gmail.com> References: <CAOjFWZ4S42mebL15iT8=TLcfvabBWeUdLDzi_d3WfhKTpuGdOw@mail.gmail.com>
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Try setting vfs.zfs.free_max_blocks to 100000 (this is an arbitrary number, can be larger, limits maximum blocks being freed per txg; see https://svnweb.freebsd.org/base?view=revision&revision=271532 for details). You can inspect the progress with DTrace by looking at zfs-dbgmsg. On Wed, Jan 4, 2017 at 10:30 AM, Freddie Cash <fjwcash@gmail.com> wrote: > Is there a way to check the progress of a background destroy process? > > I did a very bad thing in the middle of December. "zfs destroy -r > poolname/dataset", where there's approx 40 TB of data in that dataset, > spread across about 400 snapshots, sitting on a dedupe-enabled pool. :( > (Usually, I delete individual snapshots, but thought I would try a > recursive destroy instead.) > > Needless to say, the 128 GB of RAM in the box, with 128 GB of L2ARC on SSD, > is not enough to hold the DDT, and the box deadlocks after about 8 hours of > disk churning. Once Wired memory goes above 120 GB, the system is > unresponsive to everything, including pings. > > During that 8 hour period, the pool is usable; I can read and write data to > the pool, I can create and destroy snapshots, and I can receive snapshots > from other systems. But the background destroy continues to run after > every boot, continues to churn through RAM, and locks everything up after > about 8 hours. > > This has been going on for several weeks now. > > Is there any way to check the progress of the background destroy to see how > much longer this will continue, how much data has been freed, how much of > the DDT has been updated, etc? "zfs list" shows very little change in free > space. > > Or am I just going to have to live with resetting the box every 8-10 hours > for the next few weeks? Unfortunately, adding more RAM to the box isn't an > option right now. :( > > -- > Freddie Cash > fjwcash@gmail.com > _______________________________________________ > freebsd-fs@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" >
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