Linux Storage - /proc/scsi/scsi
Linux Storage Solution · Config document · referenced from LUNs seen and SCSI bus rescan
The listing of every SCSI device attached to HV01 as the kernel printed it in /proc/scsi/scsi: the local HP Smart Array controller and its logical volume on host0, and six 3PAR virtual volumes plus one enclosure device on each of the two FC hosts. It is the first of the three examples at the end of the notes, the one the section "the SCSI devices attached to the system" refers to for the details. It ran as root on HV01 and reads only.
| Item | Value |
|---|---|
| Path | /proc/scsi/scsi |
| On which host | HV01, the first blade (HP BL660c Gen8) |
| Run as | root |
| Devices | 16: two on host0 (hpsa), seven on host1 and seven on host2 (qla2xxx) |
| Array firmware | Rev: 3122 on every 3PAR device; the notes do not say which 3PAR OS version that stands for |
| Not in it | which virtual volume is which LUN, the sizes, the device names /dev/sd* |
The listing
$ cat /proc/scsi/scsi
output 49 lines
Attached devices: Host: scsi0 Channel: 03 Id: 00 Lun: 00 Vendor: HP Model: P220i Rev: 4.68 Type: RAID ANSI SCSI revision: 05 Host: scsi0 Channel: 00 Id: 00 Lun: 00 Vendor: HP Model: LOGICAL VOLUME Rev: 4.68 Type: Direct-Access ANSI SCSI revision: 05 Host: scsi2 Channel: 00 Id: 00 Lun: 00 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi2 Channel: 00 Id: 00 Lun: 01 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi2 Channel: 00 Id: 00 Lun: 02 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi2 Channel: 00 Id: 00 Lun: 03 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi2 Channel: 00 Id: 00 Lun: 04 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi2 Channel: 00 Id: 00 Lun: 05 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi2 Channel: 00 Id: 00 Lun: 254 Vendor: 3PARdata Model: SES Rev: 3122 Type: Enclosure ANSI SCSI revision: 06 Host: scsi1 Channel: 00 Id: 00 Lun: 00 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi1 Channel: 00 Id: 00 Lun: 01 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi1 Channel: 00 Id: 00 Lun: 02 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi1 Channel: 00 Id: 00 Lun: 03 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi1 Channel: 00 Id: 00 Lun: 04 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi1 Channel: 00 Id: 00 Lun: 05 Vendor: 3PARdata Model: VV Rev: 3122 Type: Direct-Access ANSI SCSI revision: 06 Host: scsi1 Channel: 00 Id: 00 Lun: 254 Vendor: 3PARdata Model: SES Rev: 3122 Type: Enclosure ANSI SCSI revision: 06
The columns
| Column | Meaning |
|---|---|
Host: scsiN | the SCSI host, host0 to host2 of /sys/class/scsi_host; scsi0 is the HP P220i controller (hpsa), scsi1 and scsi2 the two HBA ports (qla2xxx) |
Channel | the bus on the host adapter; 00 everywhere except the P220i controller device itself, which hpsa presents on channel 03 |
Id | the SCSI target ID; 00 for every FC device because each HBA port sees exactly one remote port, the array port it is zoned to |
Lun | the logical unit; the six virtual volumes are LUN 00 to 05, the enclosure device is LUN 254 |
Vendor, Model, Rev | the SCSI INQUIRY strings: HP P220i and HP LOGICAL VOLUME for the local controller, 3PARdata VV for a 3PAR virtual volume and 3PARdata SES for its enclosure service device, firmware 3122 |
Type | RAID for the controller, Direct-Access for a disk, Enclosure for the SES device |
ANSI SCSI revision | the SCSI standard level the device reports: 05 (SPC-3) for the HP devices, 06 (SPC-4) for the 3PAR ones; the mapping of the number to the standard is my understanding |
Two things to read with care. The kernel lists scsi2 before scsi1; the order is the order in which the devices were registered, not the host number, and it says nothing about the paths. And the six VV entries under scsi1 and the six under scsi2 are the same six virtual volumes seen over two paths, one through each fabric; the notes stop before the multipath layer that would fold them into six devices, and they do not say which virtual volume carries which LUN number. The SES device at LUN 254 is the enclosure-services device that a 3PAR host persona with the SESLun element presents next to the volumes; it is not a disk and nothing in the notes uses it.
Checked against Linux 7.2, RHEL 10.2 and HPE 3PAR OS 3.3.2
| As built | Today |
|---|---|
cat /proc/scsi/scsi | Still in the kernel behind CONFIG_SCSI_PROC_FS, which the Fedora and RHEL kernels enable, described as "superseded by files in sysfs but many legacy applications rely on this". The replacement is lsscsi (0.32 in RHEL 9 and 10 and in SLES 15 SP7 and 16.0, r0.33 upstream), which prints the same H:C:T:L, vendor, model and revision on one line per device |
3PARdata SES at LUN 254 | Documented by HPE as the SES device enabled by host persona 1 "Generic" and persona 2 "Generic-ALUA" (SESLun), used by HPE Host Explorer to report the host to the array; the HP 3PAR Citrix guide of 2014 warns that exporting a volume at LUN 254 needs a host reboot before it can be used |
Rev: 3122 | No HPE document maps the INQUIRY revision to a 3PAR OS version; HPE's own examples show 3110 in a 2013 guide and 3140 in the 2021 guides. The newest 3PAR OS is 3.3.2 EMU1 (July 2026), not qualified for the 7000 series, whose last version was 3.3.1 |
| HP 3PAR StoreServ 7400 | End of life announced 30 April 2017, end of service and support life 31 October 2022; successors Primera (2019), Alletra 9000 (2021), Alletra Storage MP B10000 (2024) |
| six volumes seen twice, no multipath | HPE recommends host persona 2 "Generic-ALUA" today (the only option from RHEL 7 on); on current Red Hat releases the 3PAR multipath settings are built in and /etc/multipath.conf needs no device section, only to exist |
Reading 3122 as 3PAR OS 3.1.2 is my own inference from those two examples, plausible and not verified; the notes do not say which 3PAR OS the array ran. The listing is therefore still readable today, but I would take it with lsscsi and expect to see it folded by multipath -ll before using a single volume.