2011/7/14 Peter Hamilton <peterghamilton@gmail.com>:
I'm trying to find out what the negotiated speed is on a SATA port. dmesg reports the negotiated speed, but I'm hoping to find it somewhere in /sys or /proc (or some other tool). Scraping dmesg is a messy process as I'm starting with a block device. I would have to trace the block device to the scsi address and translate that to an ata address. Here's the scsi and block device info from dmesg:
scsi 7:0:0:0: Direct-Access ATA WDC WD1600AAJS-2 01.0 PQ: 0 ANSI: 5 sd 7:0:0:0: [sdd] 312581808 512-byte logical blocks: (160 GB/149 GiB) sd 7:0:0:0: [sdd] Write Protect is off sd 7:0:0:0: [sdd] Mode Sense: 00 3a 00 00 sd 7:0:0:0: [sdd] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sd 7:0:0:0: [sdd] Attached SCSI disk sd 7:0:0:0: Attached scsi generic sg3 type 0 Here's the corresponding ata info from dmesg: ata7: SATA link up 3.0 Gbps (SStatus 123 SControl 370) ata7.00: ATA-8: WDC WD1600AAJS-22L7A0, 01.03E01, max UDMA/133 ata7.00: 312581808 sectors, multi 0: LBA48 NCQ (depth 31/32), AA ata7.00: configured for UDMA/133
Finding the SATA link speed in dmesg would be much cleaner than scraping dmesg. Does anyone know where I might find that? Also, for a SAS HBA, the link speed is not reported to dmesg. Does anyone know how to find the link speed for a SAS drive? Thanks, Peter Take a look at /sys/class/ata_link/linkX/sata_spd Where X should be the number of your SATA port. There probabably exists something equivalent for SAS but I don't have a controller so I can't tell for sure.
Mirco