LCTL-POOL_ADD(8)

LCTL-POOL_ADD(8) 💖

okay bestie, welcome to lctl-pool_add — section 8 of the Lustre Configuration Utilities, aka the girlboss move where you add OSTs to a named pool. let's get into it 🫶

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✨ NAME ✨

lctl-pool_add — add OSTs to a named pool 💅

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🌸 SYNOPSIS 🌸

lctl pool_add [--nowait|-n] FSNAME.POOLNAME OST_INDEX1 [OST_INDEX2...]
lctl pool_add [--nowait|-n] FSNAME.POOLNAME OST_RANGE1 [OST_RANGE2...]

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🦋 DESCRIPTION 🦋

So what we're doing here is adding one or more OSTs to the pool named POOLNAME inside the filesystem named FSNAME. Iconic. There are a few formats you can use to name those OSTs, and ngl the options are giving versatility.

The simplest one? Just hand over a list of OST_INDEX numbers or OST names. Easy. But you can also drop an OST_RANGE expression shaped like [START-END] or [START-END/STEP], which adds a whole bunch of OSTs with index numbers from START to END inclusive, and if you add the STEP part it skips every STEP index values. lowkey powerful.

NOTE: after the MGS configuration gets updated, this command will wait up to 12s and check if pools are updated on a client — unless you used the --nowait option. And heads up: if the MGS is on a separate node from the MDS, a Lustre client must be mounted on the MGS node while the lctl commands are being run for this to work. Otherwise, the client check is just skipped. no drama, just facts. 🌈

This named list of OSTs is what lfs-setstripe(1) can use to specify which OSTs new files get created on. BUT — super important — the OSTs that make up a specific pool may change over time, and what's actually stored on each file is the poolname used at creation time, not necessarily the OSTs sitting in the current pool. periodt. 💀

The lfs-find(1) command can locate files that were initially created on the specified poolname. Meanwhile lfs-df(1) can show you just the free space or inodes in a named pool. And lfs-quota(1) plus lfs-setquota(1) can use a pool name to get/set a quota limit for OSTs in the pool. the whole squad is eating. 👑

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💅 OPTIONS 💅

• -n, --nowait — do not wait and check if the pool is updated on a client. this is the move when you're calling a lot of lctl pool_* commands in a row, so you don't sit there waiting for each one to finish. 💅

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🎀 EXAMPLES 🎀

Create a pool named flash in the testfs filesystem:

# lfs pool_new testfs.flash

Add OSTs numbered 8, 10, and 12 through 14 to the testfs.flash pool:

# lfs pool_add testfs.flash 8 10 12-14

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👑 AVAILABILITY 👑

lctl pool_add is part of the lustre(7) filesystem package since release 1.7.0 ✨

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🫶 SEE ALSO 🫶

lfs-df(1), lfs-find(1), lfs-setstripe(1), lustre(7), lctl(8), lctl-pool_new(8)

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and that's the whole page, bestie 💖 this was Lustre, dated 2025-05-01, and yeah the manual page title is literally LCTL-POOL_ADD(8) — go forth and pool responsibly 🧚🌸