I''m new with ZFS, but I have had good success using it with raw physical disks. One of my systems has access to an iSCSI storage target. The underlying physical array is in a propreitary disk storage device from Promise. So the question is, when building a OpenSolaris host to store its data on an external iSCSI device, is there anything conceptually wrong with creating a raidz pool from a group of "raw" LUNs carved from the iSCSI device? Thanks for your advice. -- This message posted from opensolaris.org
----- Original Message -----> I''m new with ZFS, but I have had good success using it with raw > physical disks. One of my systems has access to an iSCSI storage > target. The underlying physical array is in a propreitary disk storage > device from Promise. So the question is, when building a OpenSolaris > host to store its data on an external iSCSI device, is there anything > conceptually wrong with creating a raidz pool from a group of "raw" > LUNs carved from the iSCSI device?The best would be to export the drives in JBOD style, one "array" per drive. If you rely on the Promise RAID, it you won''t be able to recover from "silent" errors. I''m in the progress of moving from a NexSAN RAID to a JBOD-like style just because of that (we had data corruption on the RAID, stuff the NexSAN box didn''t detect, as the drives didn''t detect it). As this NexSAN box can''t export true JBOD, I export each pair of drives as a stripe, and use them in VDEVs in RAIDz2s and a spare or two. While not as good as local drives, it''ll be better than trusting the ''hardware'' RAID on the box (which has proven to be unable to detect silent errors). Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 roy at karlsbakk.net http://blogg.karlsbakk.net/ -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et element?rt imperativ for alle pedagoger ? unng? eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer p? norsk.
> >The best would be to export the drives in JBOD style, one "array" per > >drive. If you rely on the Promise RAID, it you won''t be able to > >recover from "silent" errors. I''m in the progress of moving from a > >NexSAN RAID to a JBOD-like style just because of that (we had data > >>corruption on the RAID, stuff the NexSAN box didn''t detect, as the > >drives didn''t detect it). As this NexSAN box can''t export true JBOD, > >I export each pair of drives as a stripe, and use them in VDEVs in > >RAIDz2s and a spare or two. While not as good as local drives, it''ll > >be >better than trusting the ''hardware'' RAID on the box (which has > >proven to be unable to detect silent errors). > > Yup, we just did the same thing with our PAC storage units. Created 48 > Raid 0 stripes with 1 drive each. We originally tried 4 drives per > Raid 0 stripe but we ran into massive performance hits.In case someone gets across NexSAN SATABOY boxes, keep in mind that they can neither do JBOD nor make more than 14 RAID sets. I ended up exporting three drives for each RAID-0 set and then used RAIDz2 across them together with a spare. Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 roy at karlsbakk.net http://blogg.karlsbakk.net/ -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et element?rt imperativ for alle pedagoger ? unng? eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer p? norsk.