From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Is this stupid? Date: Mon, 5 Dec 2011 17:01:14 +1100 Message-ID: <20111205170114.49cf7437@notabene.brown> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/PFTGFnrT7ME0zez0/O7B+cs"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Leslie Rhorer Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/PFTGFnrT7ME0zez0/O7B+cs Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sun, 4 Dec 2011 16:28:25 -0600 "Leslie Rhorer" wro= te: > I have a system - one that is not expandable - that has relatively limited > RAM, comparatively speaking, and must boot from a usb stick. The system > hosts a RAID array, but one cannot assume the RAID array is available when > the system boots. IOW, I want to be able to take down the RAID array for > maintenance, possibly booting the system with no array created, at all. >=20 > On the other hand, USB sticks have a limited number of writes available > before they fail, so I don't want the system to be thrashing the flash dr= ive > any more than necessary. At this time, I have /var/run, /var/log, > /var/lock, and /tmp mounted as tmpfs file systems. What I propose is to = run > an init script that checks to see if the array is mounted, and if so appe= nds > files in the aforementioned directories to existing directories on the ar= ray > and then remounts and binds the directories on the array. The stop call = in > the script will reverse the process so the system can shutdown or so I can > take the array offline after booting for maintenance. Is this unwise? A= m I > missing something crucial that might cause the system to blow up? Sounds reasonably sane. After the bind mount you would need to make sure any process with a file open in one of those directories re-opens the file. So you might want to restart syslogd. NeilBrown --Sig_/PFTGFnrT7ME0zez0/O7B+cs Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBTtxeKjnsnt1WYoG5AQKLMA//YXnia+IchksnWb7ZgNsj52EUNV39k87C 8rKYYqc+YwYkWw54aSC0+QFH+lj8dt2tX1iTB7VKAqz07MlsTmlQgvOJi8qopenK cpzXszXCUFhPoV18yA0SfRYJzPFPE7S6KOXIwWgLtPjf0ZfJLtnNYESYwctoxMFj j8tpJeH9jFFrh6NNY0l/5IHZI/vkrLXDEhqaL3+w3ngnRHhQqt6Pl9QRS3XrUFbc Vo4DbzykWec0n3pOAcfxcx4kl3lscQvEgvBc4dJi3Fyb7OLiFG2/zBRV1axIe+go twWywrOVz3HOW13bGLGRYBIjp/vUaae39D6cHelxldwu61gKU6OQkpng8GXsIiLh oVG7Uh5wAXiI/Vw+mDqN2u11VxRssOPx/Ve2+vH1Umcd5SGKv/u2oOKiUeDz865g z3mXwErRXV6UwieD1jN0iJe/cNjgjzB2YD6/+WY+cczXAwS/IiCeUKZy8ZlzCPR0 fmUJqHWj137WkWTUMoiWkUNK/oZbYFdLdYU766KuB2BsnOCnzI8LzTf/DYg0brNI SXewNCFdXLVQO8KxaV5WvcavoNzMrYNq2AEZCIwNEOfNBkj0CK+eDAlVpxYX/i+9 ZjvlxPQsKCRbPdyoFtKqpp1QZDHNr8jxXpz3/PDeSHpZY6PX3CgnskGoD6ktTFAJ yXZaCSGlmXE= =lBnf -----END PGP SIGNATURE----- --Sig_/PFTGFnrT7ME0zez0/O7B+cs--