Re: [zfs-discuss] Two disks giving errors in a raidz pool, advice needed
2012-04-23 9:35, Daniel Carosone wrote: I'll try to leave all 6 original disks in the machine while replacing, maybe zfs will be smart enough to use the 6 drives to build the replacement disk ? I don't think it will.. others who know the code, feel free to comment otherwise. Well, I've heard (and made) such assumption for a few times - like that a resilver to a hotspare disk would try to use whatever source sectors are available, in essense making raidzN+1 during the process. It is quite possible that several disks of the array have errors simultaneously, but there is also a chance that the errors reside in sectors belonging to different zfs blocks, thus much or all of data is recoverable - but the process needs all of the original disks. Thinking that the functionality is in the robust ZFS is at least reasonable. 1) Does it exist in reality? 2) If the code is not there, is it a worthy RFE, maybe for GSoC? //Jim ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Two disks giving errors in a raidz pool, advice needed
So this is a point of debate that probably deserves being brought to the floor (probably for the umpteenth time, but indulge me). I've heard from several people that I'd consider experts that once per year scrubbing is sufficient, once per quarter is _possibly_ excessive, and once a week is downright overkill. Since scrub thrashes your disk, I'd like to avoid it if at all possible. My opinion is that it depends on the data. If it's all data at rest, ZFS can't correct bit-rot if it's not read out on a regular interval. My biggest question on this? How often does bit-rot occur on media that isn't read or written to excessively, but just spinning most of the day and only has 10-20GB physically read from the spindles daily? We all know as data ages, it gets accessed less and less frequently. At what point should you be scrubbing that old data every few weeks to make sure a bit or two hasn't flipped? FYI - I personally scrub once per month. Probably overkill for my data, but I'm paranoid like that. -Matt -Original Message- How often do you normally run a scrub, before this happened? It's possible they were accumulating for a while but went undetected for lack of read attempts to the disk. Scrub more often! -- Dan. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
