LCTL-PCC(8)

NAME
lctl-pcc - commands used to interact with PCC features

SYNOPSIS
lctl pcc add MNTPATH PCCPATH [--param|-p PARAM]
lctl pcc del [--keep|-k] MNTPATH PCCPATH
lctl pcc clear [ --keep | -k ] MNTPATH
lctl pcc list MNTPATH

DESCRIPTION

lctl pcc add MNTPATH PCCPATH [--param|-p PARAM]
    Add a PCC backend specified by HSM root path PCCPATH on a Lustre filesystem client instances with the mount point referenced by MNTPATH. The parameter PARAM is a string in the form of name-value pairs to config the PCC backend such as read-write attach id (archive ID) or read-only attach id and auto caching rule. i.e. for the string "projid={500}&fname={*.h5} rwid=2", the first substring of the config parameter is the auto caching rule. Where "&" represents the logical conjunction operator while "," represents the logical disjunction operator. The example rule means that new files are only auto cached if the project ID is 500 and the suffix of the file name is "h5". "rwid" represents the read-write attach id (2) which value is same as the archive ID of the copytool agent running on this PCC node. In addition to the equal (=) operator, it also supports greater than (>) and less than (<) comparison operators. The following rule expressions are supported:
        - "projid={100}&size>{1M}&size<{500G}"
        - "projid>{100}&projid<{110}"
        - "uid<{1500}&uid>{1000}"
    Currently each PCC backend only has one rule which is configured when setup PCC backend on a client. If a user wants to change the rule, the PCC backend needs to be removed first and then added back with a new rule.

lctl pcc del [--keep|-k] MNTPATH PCCPATH
    Delete a PCC backend specified by path pccpath on a Lustre client referenced by the mount point of mntpath.

lctl pcc clear [--keep|-k] MNTPATH
    Remove all PCC backend on a Lustre client referenced by the mount point of mntpath.

lctl pcc list MNTPATH
    List all PCC backends on a Lustre client referenced by the mount point of mntpath.

OPTIONS

-p, --param
    Specifies the configuration parameters for a PCC backend.

-k, --keep
    By default, when remove a PCC backend from a client, the action is to scan the PCC backend fs, and then uncache (detach and remove) all scanned PCC copies from PCC by FIDs. With the option "--keep|-k", the "lctl pcc del|clear" command just removes the PCC backend from the Lustre client, and retains the data on the cache. In this way, the PCC-RW backend falls back as a tranditional HSM storage solution since the copytool is still running at this client.

AVAILABILITY
lctl pcc
    is part of the lustre(7) filesystem package since release 2.13.0

SEE ALSO
lfs(1), lfs-hsm(1), lfs-pcc(1)