Multipath-IO
多路径存储 I/O 在 Alpine Linux 安装介质上默认未启用。Linux 上的多路径 I/O 依赖于 devicemapper 和 eudev。
注意： 不支持从多路径 I/O 设备启动，这需要在 mkinitfs 软件包中进行更改。
# apk add lsscsi multipath sg3_utils # modprobe dm_mod dm-multipath # setup-udev
列出您的 SCSI 磁盘。
# lsscsi -isw | grep disk [2:0:0:0x0000] disk 600140547f7876a3412466aab5f0debf /dev/sda 3600140547f7876a3412466aab5f0debf 1.07GB [2:0:0:0x0001] disk 600140547f7876a3412466aab5f0debf /dev/sdb 3600140547f7876a3412466aab5f0debf 1.07GB
在大多数情况下，您的 LUN 将被列入黑名单，因此以下命令可能不会显示任何输出。
# multipath -v2 -d # dry-run
如果是这样，则运行更详细的检查。
# multipath -v3 -d # dry-run ...skipped... ===== paths list ===== uuid hcil dev dev_t pri dm_st chk_st vend/prod 3600140547f7876a3412466aab5f0debf 2:0:0:0 sda 8:0 50 undef undef LIO-ORG,t 3600140547f7876a3412466aab5f0debf 2:0:0:1 sdb 8:16 50 undef undef LIO-ORG,t Mar 15 17:32:27 | libdevmapper version 1.02.170 (2020-03-24) Mar 15 17:32:27 | DM multipath kernel driver v1.14.0 Mar 15 17:32:27 | sda: udev property ID_WWN whitelisted Mar 15 17:32:27 | wwid 3600140547f7876a3412466aab5f0debf not in wwids file, skipping sda Mar 15 17:32:27 | sda: orphan path, only one path Mar 15 17:32:27 | sdb: udev property ID_WWN whitelisted Mar 15 17:32:27 | wwid 3600140547f7876a3412466aab5f0debf not in wwids file, skipping sdb Mar 15 17:32:27 | sdb: orphan path, only one path Mar 15 17:32:27 | unloading alua prioritizer Mar 15 17:32:27 | unloading const prioritizer Mar 15 17:32:27 | unloading tur checker
然后检查 multipath 默认值。
# multipath -t
...skipped...
blacklist {
devnode "!^(sd[a-z]|dasd[a-z]|nvme[0-9])"
device {
vendor "SGI"
product "Universal Xport"
}
...skipped...
}
blacklist_exceptions {
property "(SCSI_IDENT_|ID_WWN)"
}
...skipped...
因此，我们的 /dev/sd[ab] 未被列入黑名单，但 ID_WWN 用于显式要求 LUN 的 wwn。
查看 wwids 文件位于何处。
# multipath -t | grep wwids_file
wwids_file "/etc/multipath/wwids"
# cat /etc/multipath/wwids # Multipath wwids, Version : 1.0 # NOTE: This file is automatically maintained by multipath and multipathd. # You should not need to edit this file in normal circumstances. # # Valid WWIDs:
让我们将您的 LUN（即通过两个 LUN 访问您的 wwn）添加到 /etc/multipath/wwids。
# multipath -a 3600140547f7876a3412466aab5f0debf wwid '3600140547f7876a3412466aab5f0debf' added # egrep -v '^(#|$)' /etc/multipath/wwids /3600140547f7876a3412466aab5f0debf/
参见，wwn 用 / 括起来。
让我们再次扫描。
# multipath -v2 -d # dry-run Mar 15 17:46:35 | 3600140547f7876a3412466aab5f0debf: setting dev_loss_tmo is unsupported for protocol scsi:unspec : 3600140547f7876a3412466aab5f0debf undef LIO-ORG,test0 size=1.0G features='0' hwhandler='1 alua' wp=undef |-+- policy='service-time 0' prio=50 status=undef | `- 2:0:0:0 sda 8:0 undef ready running `-+- policy='service-time 0' prio=50 status=undef `- 2:0:0:1 sdb 8:16 undef ready running
让我们来真的，即省略 dry-run。
# multipath -v2 Mar 15 17:48:06 | 3600140547f7876a3412466aab5f0debf: setting dev_loss_tmo is unsupported for protocol scsi:unspec Mar 15 17:48:06 | 3600140547f7876a3412466aab5f0debf: addmap [0 2097152 multipath 0 1 alua 2 1 service-time 0 1 1 8:0 1 service-time 0 1 1 8:16 1] create: 3600140547f7876a3412466aab5f0debf undef LIO-ORG,test0 size=1.0G features='0' hwhandler='1 alua' wp=undef |-+- policy='service-time 0' prio=50 status=undef | `- 2:0:0:0 sda 8:0 undef ready running `-+- policy='service-time 0' prio=50 status=undef `- 2:0:0:1 sdb 8:16 undef ready running
# multipath -ll | sed 's/^/ /' 3600140547f7876a3412466aab5f0debf dm-2 LIO-ORG,test0 size=1.0G features='0' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | `- 2:0:0:0 sda 8:0 active ready running `-+- policy='service-time 0' prio=50 status=enabled `- 2:0:0:1 sdb 8:16 active ready running
如果我们对配置感到满意，让我们添加 openrc 守护程序。
# apk add multipath-tools-openrc # rc-update add multipath boot # rc-update add multipathd boot