Hiya, I''''ve been doing a lot of research surrounding this and ZFS, including some posts on here, though I am still left scratching my head. I am planning on using slow RPM drives for a home media server, and it''s these that seem to ''suffer'' from a few problems; Seagate Barracuda LP - Looks to be the only true 512b sector hard disk. Serious firmware issues Western Digital Cavier Green - 4K sectors = crap write performance Hitachi 5K3000 - Variable sector sizing (according to tech. specs) Samsung SpinPoint F4 - Just plain old problems with them What is the best drive of the above 4, and are 4K drives really a no-no with ZFS. Are there any alternatives in the same price bracket? Who would have thought choosing a hard disk could be so ''hard''! Thanks -- This message posted from opensolaris.org
On Jul 4, 2011, at 6:42 AM, Lanky Doodle wrote:> Hiya, > > I''''ve been doing a lot of research surrounding this and ZFS, including some posts on here, though I am still left scratching my head. > > I am planning on using slow RPM drives for a home media server, and it''s these that seem to ''suffer'' from a few problems; > > Seagate Barracuda LP - Looks to be the only true 512b sector hard disk. Serious firmware issues > Western Digital Cavier Green - 4K sectors = crap write performance > Hitachi 5K3000 - Variable sector sizing (according to tech. specs) > Samsung SpinPoint F4 - Just plain old problems with them > > What is the best drive of the above 4, and are 4K drives really a no-no with ZFS. Are there any alternatives in the same price bracket?4K drives are fine, especially if the workload is read-mostly. Depending on the OS, you can tell ZFS to ignore the incorrect physical sector size reported by some drives. Today, this is easiest in FreeBSD, a little bit more tricky in OpenIndiana (patches and source are available for a few different implementations). Or you can just trick them out by starting the pool with a 4K sector device that doesn''t lie (eg, iscsi target).> > Who would have thought choosing a hard disk could be so ''hard''!I recommend enterprise-grade disks, none of which made your short list ;-(. -- richard
Richard Elling wrote:> On Jul 4, 2011, at 6:42 AM, Lanky Doodle wrote: > > >> Hiya, >> >> I''''ve been doing a lot of research surrounding this and ZFS, including some posts on here, though I am still left scratching my head. >> >> I am planning on using slow RPM drives for a home media server, and it''s these that seem to ''suffer'' from a few problems; >> >> Seagate Barracuda LP - Looks to be the only true 512b sector hard disk. Serious firmware issues >> Western Digital Cavier Green - 4K sectors = crap write performance >> Hitachi 5K3000 - Variable sector sizing (according to tech. specs) >> Samsung SpinPoint F4 - Just plain old problems with them >> >> What is the best drive of the above 4, and are 4K drives really a no-no with ZFS. Are there any alternatives in the same price bracket? >> > > 4K drives are fine, especially if the workload is read-mostly. > > Depending on the OS, you can tell ZFS to ignore the incorrect physical sector > size reported by some drives. Today, this is easiest in FreeBSD, a little bit more > tricky in OpenIndiana (patches and source are available for a few different > implementations). Or you can just trick them out by starting the pool with a 4K > sector device that doesn''t lie (eg, iscsi target). > > >> Who would have thought choosing a hard disk could be so ''hard''! >> > > I recommend enterprise-grade disks, none of which made your short list ;-(. > -- richardI''m going through this at the moment. I''ve bought a pair of Seagate Barracuda XT 2Tb disks (which are a bit more Enterprise than the list above), just plugged them in, and so far they''re OK. Not had them long enough to report on longevity. -- Andrew Gabriel
Richard On 07/04/2011 03:58 PM, Richard Elling wrote:> On Jul 4, 2011, at 6:42 AM, Lanky Doodle wrote: > >> Hiya, >> >> I''''ve been doing a lot of research surrounding this and ZFS, including some posts on here, though I am still left scratching my head. >> >> I am planning on using slow RPM drives for a home media server, and it''s these that seem to ''suffer'' from a few problems; >> >> Seagate Barracuda LP - Looks to be the only true 512b sector hard disk. Serious firmware issues >> Western Digital Cavier Green - 4K sectors = crap write performance >> Hitachi 5K3000 - Variable sector sizing (according to tech. specs) >> Samsung SpinPoint F4 - Just plain old problems with them >> >> What is the best drive of the above 4, and are 4K drives really a no-no with ZFS. Are there any alternatives in the same price bracket? > > 4K drives are fine, especially if the workload is read-mostly. > > Depending on the OS, you can tell ZFS to ignore the incorrect physical sector > size reported by some drives. Today, this is easiest in FreeBSD, a little bit more > tricky in OpenIndiana (patches and source are available for a few different > implementations). Or you can just trick them out by starting the pool with a 4K > sector device that doesn''t lie (eg, iscsi target).Are you refering to the "ahift" patches and what do you mean by tricking them by using an iscsi target? Thanks, Thomas
Thomas, On Jul 4, 2011, at 9:53 AM, Thomas Nau wrote:> Richard > > > On 07/04/2011 03:58 PM, Richard Elling wrote: >> On Jul 4, 2011, at 6:42 AM, Lanky Doodle wrote: >> >>> Hiya, >>> >>> I''''ve been doing a lot of research surrounding this and ZFS, including some posts on here, though I am still left scratching my head. >>> >>> I am planning on using slow RPM drives for a home media server, and it''s these that seem to ''suffer'' from a few problems; >>> >>> Seagate Barracuda LP - Looks to be the only true 512b sector hard disk. Serious firmware issues >>> Western Digital Cavier Green - 4K sectors = crap write performance >>> Hitachi 5K3000 - Variable sector sizing (according to tech. specs) >>> Samsung SpinPoint F4 - Just plain old problems with them >>> >>> What is the best drive of the above 4, and are 4K drives really a no-no with ZFS. Are there any alternatives in the same price bracket? >> >> 4K drives are fine, especially if the workload is read-mostly. >> >> Depending on the OS, you can tell ZFS to ignore the incorrect physical sector >> size reported by some drives. Today, this is easiest in FreeBSD, a little bit more >> tricky in OpenIndiana (patches and source are available for a few different >> implementations). Or you can just trick them out by starting the pool with a 4K >> sector device that doesn''t lie (eg, iscsi target). > > Are you refering to the "ahift" patches and what do you mean by tricking them > by using an iscsi target?This is a roundabout way to do this, but it can be done without changing any source :-) With the Nexenta or Solaris iSCSI target, you can set the blocksize for a LUN. When you create the pool for the first time, make one of the devices be an iSCSI LUN with a 4KB block size. This will cause the top-level vdev to use ashift=12. You can then replace the iSCSI LUN with a different device using "zpool replace" -- richard
On Mon, Jul 04, 2011 at 01:11:09PM -0700, Richard Elling wrote:> Thomas, > > On Jul 4, 2011, at 9:53 AM, Thomas Nau wrote: > This is a roundabout way to do this, but it can be done without changing any source :-) > With the Nexenta or Solaris iSCSI target, you can set the blocksize for a LUN. > When you create the pool for the first time, make one of the devices be an iSCSI > LUN with a 4KB block size. This will cause the top-level vdev to use ashift=12. > You can then replace the iSCSI LUN with a different device using "zpool replace"Thomas, I wrote a little more detailed recipe for this a month or two ago, look in the archives. -- Dan. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 194 bytes Desc: not available URL: <http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20110705/8fd2b19c/attachment.bin>