There is various information about - enterprise-class drives (either SAS or just enterprise SATA) - the SCSI/SAS protocols themselves vs SATA having more advanced features (e.g. for dealing with error conditions) than the average block device For example, Adaptec recommends that such drives will work better with their hardware RAID cards: http://ask.adaptec.com/cgi-bin/adaptec_tic.cfg/php/enduser/std_adp.php?p_faqid=14596 "Desktop class disk drives have an error recovery feature that will result in a continuous retry of the drive (read or write) when an error is encountered, such as a bad sector. In a RAID array this can cause the RAID controller to time-out while waiting for the drive to respond." and this blog: http://www.adaptec.com/blog/?p=901 "major advantages to enterprise drives (TLER for one) ... opt for the enterprise drives in a RAID environment no matter what the cost of the drive over the desktop drive" My question.. - does Linux md RAID actively use the more advanced features of these drives, e.g. to work around errors? - if a non-RAID SAS card is used, does it matter which card is chosen? Does md work equally well with all of them? - ignoring the better MTBF and seek times of these drives, do any of the other features passively contribute to a better RAID experience when using md? - for someone using SAS or enterprise SATA drives with Linux, is there any particular benefit to using md RAID, dmraid or filesystem (e.g. btrfs) RAID (apart from the btrfs having checksums)? -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
