On 2-Dec-08, at 8:24 AM, Glaser, David wrote: > Ok, thanks for all the responses. I'll probably do every other week > scrubs, as this is the backup data (so doesn't need to be checked > constantly).
Even that is probably more frequent than necessary. I'm sure somebody has done the MTTDL math. IIRC, the big win is doing any scrubbing at all. The difference between scrubbing every 2 weeks and every 2 months may be negligible. (IANAMathematician tho) --T > I'm a little concerned about the time involved to do 33TB (after > the 48TB has been RAIDed fully) when it is fully populated with > filesystems and snapshots, but I'll keep an eye on it. > > Thanks all. > > Dave > > > -----Original Message----- > From: Paul Weaver [mailto:[EMAIL PROTECTED] > Sent: Tuesday, December 02, 2008 8:11 AM > To: Glaser, David; zfs-discuss@opensolaris.org > Subject: RE: [zfs-discuss] How often to scrub? > >> I have a Thumper (ok, actually 3) with each having one large pool, > multiple >> filesystems and many snapshots. They are holding rsync copies of > multiple >> clients, being synced every night (using snapshots to keep > 'incremental' >> backups). >> >> I'm wondering how often (if ever) I should do scrubs of the pools, or > if >> the internal zfs integrity is enough that I don't need to do manual > scrubs >> of the pool? I read through a number of tutorials online as well as > the zfs >> wiki entry, but I didn't see anything very pertinent. Scrubs are I/O >> intensive, but is the Pool able to be used normally during a scrub? I >> think the answer is yes, but some confirmation helps me sleep at > night. > > Scrubs are the lowest priority, so I understand it should > theoretically > work fine. > > We've got two 48TB thumpers, with a nightly rsync from the main to the > reserve. I'm currently running a scrub every Friday at 23:02, which > last > week took 5h15 to scrub the 7TB of used data (about 5TB of real, > 2TB of > snapshots) on the single pool. That's about 380MBytes/second. > > > -- > > "09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0" > > Paul Weaver > Systems Development Engineer > News Production Facilities, BBC News > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
