is multipath -F safe? (flush all unused paths)

14,225

Yes, it is safe. However, if any other subsystem is using them (lvm, mount) or you have queued I/Os the paths won't be flushed and you'll need to figure out why.

Edit: use -f device to be safe.

See http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/Online_Storage_Reconfiguration_Guide/removing_devices.html

14,225

carillonator

Systems/Database Engineer who dabbles in web design.

Updated on September 17, 2022

Comments

carillonator almost 2 years
from multipath manpage:
```
-F     flush all unused multipath device maps
```
is this a safe operation? I have a bunch of old dead paths and would like to clear them out, but want to make sure it's absolutely safe to do. I've heard ql-scan-lun.sh -r, which is supposed to do the same thing, can interrupt visibility of all the LUNS. using qlogic qla2xxx hbas.
- Deb over 13 years
  
  What OS are you using? It looks Linuxy, but guessing could be catastrophic.
- Philip over 13 years
  
  "I ... would like to clear them out" - Why?
- carillonator over 13 years
  
  @Chris, we are doing maintenance on our san switches and need to be able to see any newly failed paths, so having no failed paths to start is helpful.
- carillonator over 13 years
  
  @sysadmin1138, multipathd is built into the linux kernel.
- Deb over 13 years
  
  Multipath (MPIO is the spec) is built into a lot of things, it comes out of the box in Win2008, Solaris, FreeBSD, and even NetWare, but Linux wasn't stated in your question or tags.
MastaJeet over 13 years

Actually, which OS are you using? My answer assumed RHEL5.
carillonator over 13 years

great, thanks. CentOS 5.2, so essentially RHEL5.