vzcptcheck(8)

💖 vzcptcheck — the CPT vibe checker (section 8, Containers) 💖

okay bestie, gather round, because this little utility is lowkey a baddie. it's vzcptcheck, and it lives in the Containers part of the manual. she's a low-level utility, meaning she doesn't do small talk — she shows you CPT properties and tests them, and that's the whole personality. 🎀

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🌸 NAME 🌸

vzcptcheck — show/test CPT properties. that's it, that's the job, and she does it flawlessly. ✨

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🦋 SYNOPSIS 🦋

vzcptcheck property [argument ...]
vzcptcheck help

two moods, one queen. 💅

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💜 DESCRIPTION 💜

so here's the tea: this low-level utility is the one vzmigrate(8) calls up when it needs to check if a container can be successfully restored on a destination system before it does a live migration. she's the vibe check before the big move, fr fr. currently she's able to check CPT version and CPU flags compatibility — those are her two areas of expertise and she's obsessed with both. 🫶

she's got two modes of operation:

• showing mode — you name a property and give her zero arguments, and she just shows you the thing. no notes. 👑
• testing mode — you name a property and then hand her one or many arguments, and she tests it. 🔥

generally, the move is: run vzcptcheck on one node to get a property, then run it on the other node to check for that property. two nodes, one conversation, very main character energy. 💫

⚠️ real talk though: this utility does not guarantee that migration will succeed even if all the tests pass. she merely gives you a way to prevent a migration that will definitely fail. so like, passing the vibe check is not a promise, it's a filter. 💀

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✨ OPTIONS ✨

🍓 version things

• vzcptcheck version — run this on the source node to get the CPT version number. 📥
• vzcptcheck version num — then, to check if that version number is supported, run this on the destination node. 📤

🌈 caps things

• vzcptcheck caps — run this on the destination node to get the CPU capabilities number. 🧠
• vzcptcheck caps ctid capnum — run this on the source node to check if a running CT can be live migrated to a node with such a CPU. 🏃♀️
• vzcptcheck caps capnum — the form without ctid. use this one to check if a suspended container can be migrated, i.e. whether it can be restored on the destination node. 😴

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🌟 EXIT STATUS 🌟

• in showing mode: returns 0 on success, or 1 if there's an error. 🎉
• in testing mode: returns 0 if migration is possible (test passed 💖), 1 if there's an error (😭), or 2 if migration is not possible (test failed 💀).

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🎀 EXAMPLES 🎀

so say you wanna check if CT 123 can be migrated to $DEST. run the following commands on the source node. (heads up: error checking is omitted here for brevity, don't come for me 🙈)

VEID=123
VERSION=$(vzcptcheck version)
echo Got CPT version: $VERSION
ssh root@$DEST vzcptcheck version $VERSION
echo Version check result: $?
CAPS=$(ssh root@$DEST vzcptcheck caps)
echo Got caps: $CAPS
vzcptcheck caps $VEID $CAPS
echo Caps check result: $?

if both tests pass, you should get 0 as a result for both checks. slay. 🎊

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👀 SEE ALSO 👀

vzmigrate(8). that's her bestie, that's who she's out here doing all this for. 🫶

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📜 LICENSE 📜

Copyright (C) 2013-2015, Parallels, Inc. Licensed under GNU GPL v2. iconic, legally protected, periodt. 💅

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and that's the whole page, babe — this one shipped as part of OpenVZ, dated 21 Apr 2015. go forth and migrate responsibly. 🌸💖✨