forked from pool/s390-tools
207 lines
8.8 KiB
Diff
207 lines
8.8 KiB
Diff
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Subject: lstape, lsluns: handle non-zfcp; lin_tape multiple paths
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From: Steffen Maier <maier@linux.ibm.com>
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Description: lstape, lsluns: handle non-zfcp; lin_tape multiple paths
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Symptom: lstape shows unexpected additional Device suffix numbers in
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excess output columns for each additional path of the same
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tape/changer driven by the IBM lin_tape device driver
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(independent of actual path failover enablement in lin_tape).
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It also shows a wrong number of found devices in the header
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(without --scsi-only).
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lstape prints error about "Unexpected extra argument:" and the
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usage for "sg_inq" along with wrong tabular output.
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lsluns prints ENOENT error text for "cat" on SCSI device sysfs
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attributes hba_id, wwpn, and fcp_lun.
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lstape with --verbose option prints ENOENT error text for
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"cat" on SCSI device sysfs attributes hba_id and wwpn.
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lstape man page: Description of --type and <devbusid> filter
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for channel tapes is incomplete. SCSI output description is
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incomplete.
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lstape shows "N/A" instead of the HBA device bus-ID with
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virtio-scsi-ccw.
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Problem: s390-tools-1.8.0 before the first upstream commit b627b8d8e1ab
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("Initial s390-tools-2.0.0 import") introduced SCSI
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tape/changer output for lstape. It used the SCSI device serial
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number as lookup key to find a match in IBM lin_tape device
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driver proc-fs output for a given SCSI device name. Multiple
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paths to the same tape/changer have the same serial number.
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Multiple matches cause excess arguments to printf. Explaining
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the resulting output, the bash man page says: "The format is
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reused as necessary to consume all of the arguments." This
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also causes a wrong number of found devices.
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The default bash settings have nullglob disabled so if
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$SCSI_DEV/scsi_generic* aka
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/sys/bus/scsi/devices/*:*:*:*/scsi_generic* does not match
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anything, it leaves the glob pattern unmodified and
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SG_DEV=$(basename $SG_DEV/*) results in the literal "*". If
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$SG_INQ exists, it invoked sg_inq with more than the one
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allowed positional argument for a SCSI generic device node
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"sg_inq /dev/*". Causing error messages and the usage of
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sg_inq to land in $TAPE_SERIAL.
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lsluns iterates SCSI generic devices and unconditionally
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reads zfcp-specific SCSI device sysfs attributes hba_id, wwpn,
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and fcp_lun.
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lstape --verbose unconditionally reads zfcp-specific SCSI
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device sysfs attributes hba_id and wwpn.
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<devbusid> filter missing from synopsis. <device-type> example
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at wrong place with <devbusid> filter. <devbusid> filter
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option description is a duplicate of <device-type> filter
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option description. SCSI output description misses fields.
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Lstape only used the zfcp-specific sysfs attribute hba_id.
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Solution: Prefer sysfs to find lin_tape device name for SCSI device.
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Fallback: The lin_tape proc-fs output format has changed over
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the years. The HBA device driver string can contain whitespace
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(e.g. "Virtio SCSI HBA") and breaks the field numbers with
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tokenized parsing. Grep for the SCSI device name as word (to
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skip names with same substring, such as 0:0:1:1 also matching
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0:0:1:10) and cut the first field 'Number' (lin_tape device
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name suffix). If there is no SCSI column at all [lin_tape
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before v2.2.0] (and no SCSI LLDD or other column with a name
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accidentally matching an existing SCSI device name), we get no
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match and better bail out with the initialized "N/A" for the
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lstape column "Device".
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To not have to rely on the nullglob setting, explicitly check
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for the existence of $SCSI_DEV/scsi_generic before evaluating
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SG_DEV=$(basename $SG_DEV/*). Also handle availability of
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sg_inq but absence of scsi_generic individually to provide the
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user with a hint if only sg is missing.
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Simply skip non-zfcp SCSI devices, such as iSCSI or
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virtio-scsi-ccw, to not erroneously access absent attributes.
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Assume "N/A" for HBA and WWPN of non-zfcp SCSI devices, such
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as iSCSI or virtio-scsi-ccw, to not erroneously access absent
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zfcp-specific sysfs attributes.
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Add <devbusid> filter to synopsis. Move <device-type> example
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to <device-type> option. Replace <devbusid> filter option
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description. Move existing SCSI output description to a new
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subsection and add description of missing fields.
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Also search sysfs for an ancestor with subsystem ccw.
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Reproduction: Attach more than one path to the same SCSI tape or changer and
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load the IBM lin_tape device driver.
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Unload sg kernel module.
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Attach non-zfcp SCSI devices such as iSCSI or virtio-scsi-ccw.
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Attach non-zfcp SCSI devices such as iSCSI or virtio-scsi-ccw.
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man lstape
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Attach SCSI tape or changer with virtio-scsi-ccw to a KVM
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guest and run "lstape --verbose".
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Upstream-ID: -
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Problem-ID: 170633
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Signed-off-by: Steffen Maier <maier@linux.ibm.com>
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---
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zconf/lstape.8 | 68 +++++++++++++++++++++++++++++++++++++++++++++------------
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1 file changed, 54 insertions(+), 14 deletions(-)
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--- a/zconf/lstape.8
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+++ b/zconf/lstape.8
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@@ -29,20 +29,6 @@ channel attached tape devices this outpu
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/proc/tapedevices (which is obsolete) but also includes offline devices. By
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default all tape devices are displayed.
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-Since SCSI tape devices are accessed differently to channel attached tape
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-devices they are only visible if they are known to the SCSI layer. There
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-are at least two possible drivers that can claim a SCSI tape device and the
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-lstape command tries to find out which one this is. For the generic tape
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-and changer driver the device names start with "st" or "sch", while for the
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-IBM tape driver this would be "IBMtape" or "IBMchanger". If "N/A" is shown,
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-the correct driver could not be obtained.
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-
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-The serial number of a SCSI tape can be displayed with the --verbose option. If
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-there is no sg_inq command available "NO/INQ" is shown as the serial number
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-of the tape.
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-If no SCSI generic (sg) kernel support is available, "NO/SG" is shown
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-as the serial number of the tape and "N/A" for the "Generic" column.
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-
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The lstape command without the --ccw-only option causes extra SAN traffic
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for each SCSI tape or changer device by invoking the sg_inq command.
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@@ -89,6 +75,55 @@ tape devices).
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Limits the output to information about the specified tape device or
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devices only. For CCW-attached devices only.
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+.SH OUTPUT FIELDS FOR SCSI TAPE/CHANGER DEVICES
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+.TP
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+.B Generic
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+SCSI generic device file for the tape drive, for example /dev/sg0.
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+"N/A" if the SCSI generic (sg) kernel functionality is not available.
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+.TP
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+.B Device
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+Main character device node file for accessing the tape drive or medium changer.
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+SCSI tape devices are only visible if they are known to the SCSI layer. There
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+are at least two possible drivers that can claim a SCSI tape device. The
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+lstape command tries to determine the device driver. For the generic tape
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+and changer driver the device names start with "st" or "sch", while for the
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+IBM tape driver this would be "IBMtape" or "IBMchanger". If "N/A" is shown,
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+the device driver could not be determined.
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+.TP
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+.B Target
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+Linux SCSI device name in H:C:T:L format.
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+.TP
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+.B Vendor
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+The vendor field from the SCSI device.
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+.TP
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+.B Model
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+The model field from the SCSI device.
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+.TP
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+.B Type
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+"tapedrv" for a tape drive or "changer" for a medium changer.
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+.TP
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+.B State
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+The state of the SCSI device object in the kernel.
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+Any state other than "running" can indicate problems.
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+
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+.PP
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+
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+For SCSI devices, the --verbose option additionally displays:
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+.TP
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+.B HBA
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+The device bus-ID of the FCP device
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+through which the tape drive is attached.
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+"N/A" if device is not attached through zfcp.
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+.TP
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+.B WWPN
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+The WWPN (worldwide port name) of the tape drive in the SAN.
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+"N/A" if device is not attached through zfcp.
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+.TP
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+.B Serial
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+The serial number.
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+"NO/INQ" if there is no sg_inq command available.
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+"NO/SG" if no SCSI generic (sg) kernel support is available.
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+
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.SH EXAMPLES
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\fBlstape\fR
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.RS
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@@ -99,3 +134,8 @@ List all tape devices that are available
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.RS
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Show all 3490 CCW devices that are online.
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.RE
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+
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+\fBlstape --scsi-only --verbose\fR
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+.RS
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+Show all SCSI tape or changer devices with maximum information.
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+.RE
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